Catalogue of Organisms

Bradybaenids: The Little Freaks

noreply@blogger.com (Christopher Taylor) — Wed, 19 Jun 2013 06:56:00 +0000

Just a quick one this week, as I'm busy preparing for the International Conference of Arachnology in Taipei next week. The wonderful assembly in the photograph above (by B. Frank) is a congregation of the Asian tramp snail Bradybaena similaris. The Bradybaenidae are a family of small snails, closely related to the garden snails of the Helicidae, that are mostly native to eastern Asia. However, a few species such as B. similaris have become widespread around the world as a result of human transportation. Not deliberate transportation of the snails themselves, of course, but transportation of plants and plant matter that have had the snails clinging to them. Also, recent phylogenetic studies have indicated that the Australasian snails hitherto included in the Camaenidae are in fact not close relatives of the North American representatives of that family, but should be placed close to or even within the Bradybaenidae (Wade et al. 2007).

Euhadra grata gratoides, from here.

You may already be familiar with the production by some species of snail of 'love darts', small calcareous spears that a mating snail fires into its partner. The function of the love dart is still not entirely understood, though it does seem to improve sperm uptake by the snail being darted: whether by lowering its ability to resist insemination, or because snails are mini-masochists that get off on being stabbed, I couldn't say. Most textbooks describing the use of love darts will (at least effectively) base their description on the common garden snail Cornu aspersum (or Cantareus aspersus, or whatever the heck we're supposed to be calling it these days), which leaves its love dart embedded in its partner's skin. Bradybaenids whose mating behaviour has been studied, however, do things a bit differently. Instead of abandoning its dart after a single firing, bradybaenids withdraw the dart and use it to stab their partner repeatedly, making it more of a love shiv than a love dart. And when I say repeatedly, I mean repeatedly: mating pairs of Euhadra subnimbosa would, on average, stab each other with the dart over 3300 times (Koene & Chiba 2006). So vigorous is the stabbing, in fact, that the dart pierces straight through the recipient and emerges through its foot! For those with JSTOR access, a video of the process can be seen at http://www.jstor.org/stable/10.1086/508028. And trust you to go rushing to watch a film of gastropod SM.

REFERENCES

Koene, J. M., & S. Chiba. 2006. The way of the samurai snail. American Naturalist 168 (4): 553-555.

Wade, C. M., C. Hudelot, A. Davision, F. Naggs & P. B. Mordan. 2007. Molecular phylogeny of the helicoid land snails (Pulmonata: Stylommatophora: Helicoidea), with special emphasis on the Camaenidae. Journal of Molluscan Studies 73: 411-415.

All About Buris ensipes

noreply@blogger.com (Christopher Taylor) — Mon, 10 Jun 2013 05:39:00 +0000

Sunorfa, from here.

The beetle pictured just above is not the intended subject of today's post. It is a related beetle found in Thailand, but I've used its photo instead of one of today's subject because, as far as I have been able to find, today's subject has never been illustrated. It was described as Dalmodes ensipes from San Esteban in Venezuela by Raffray in 1891, before it became de rigeur to illustrate any new species described (Raffray did illustrate a number of other species described in the same paper, but not this one). It has since been recorded from Antigua and Trinidad in the West Indies by Park et al. (1976), who also indicated that it should be placed in the genus Buris instead of Dalmodes, but did not illustrate it. Park (1942) had previously placed it in the genus Bythinophysis, but did not illustrate it then either. I have not been able to find any illustration of another species of Buris. Nor have I been able to find illustrations for any other species of Dalmodes, nor of Bythinophysis. Sadly, this is not an uncommon state of affairs for insect species. I did briefly consider the idea of composing an illustration of a potential Buris ensipes on the basis of Raffray's (1891) verbal description, but then I remembered that I was a rubbish drawer.

Buris ensipes is a member of the beetle group known as the Pselaphinae, of which another genus, Bryaxis, has previously been featured on this site. Like Bryaxis, Buris ensipes would probably be found in leaf litter, or possibly within rotting wood (specific collection details for Buris ensipes have not been recorded, but Park [1942] described pselaphines as found in both habitats). Also like Bryaxis, it is probably a micropredator, though again no record of its life habits has yet been made. Buris ensipes probably looks roughly similar to the photo of Sunorfa above, but Raffrays' (1891) description indicates that it would have shorter antennae (the first segment is described as subquadrate, and the end as obtusely pointed). A curved, transverse fovea (depression) is described as present in the rear half of the pronotum, and the elytra bear a pair of subhumeral foveae (i.e. just near the 'shoulders'). The fourth abdominal segment is toothed on either side. Also distinctive is the shape of the hind tibia, which is bisinuate with a median tooth. Overall, it is just over one and a half millimetres in length.

And that, as it stands, is just about all about Buris ensipes. Like all too many organisms, we have a morphological description, a few localities, and not a heck of a lot else. Buris ensipes just needs a little more love.

Update: A big thank you to Stephen Thorpe, who managed to do what I couldn't and locate an illustration of a Buris species, B. brevicollis, in Sharp (1887). I've reproduced the figure below; it also tallies reasonably closely with Raffray's description of B. ensipes. Potential differences between the species are that Sharp makes no mention in B. brevicollis of a toothed fourth abdominal segment like that of B. ensipes (though one should always be extremely cautious of assuming a given feature to be absent simply because a given author didn't mention it), and that Raffray referred to the tibial spine of B. ensipes as 'minute' whereas that of B. brevicollis looks quite sizable.

REFERENCES

Park, O. 1942. A study in Neotropical Pselaphidae. Northwestern University Studies in the Biological Sciences and Medicine 1: i-x, 1-403, 21 pls.

Park, O., J. A. Wagner & M. W. Sanderson. 1976. Review of the pselaphid beetles of the West Indies (Coleopt., Pselaphidae). Fieldiana Zoology 68: 1-90.

Raffray, A. 1891. Voyage de M. E. Simon au Venezuela (Décembre 1887-Avril 1888). 10^e Mémoire. Psélaphides. Annales de la Société entomologique de France, ser. 6, 10: 297-330, pl. 6.

Sharp, D. 1887. Fam. Pselaphidae. In: Biologia Centrali-Americana. Insecta. Coleoptera, vol. 2, pt 1, pp. 1-46.

Holometabolous When?

noreply@blogger.com (Christopher Taylor) — Fri, 07 Jun 2013 05:55:00 +0000

A few days ago, I asked you to guess the problem with this T-shirt (from here):

'Holometaboly' refers to the life-cycle found in insects belonging to the clade Holometabola (i.e. flies, moths, wasps, beetles, etc.), where the larval stage is significantly different in appearance to the adult stage, and the body undergoes significant reconstruction during an intervening, quiescent pupal stage. Some of you may be aware that thrips are not members of the clade Holometabola, being instead more closely related to the Hemiptera, the sucking bugs. Nevertheless, thrips can indeed be described as holometabolous, as they have evolved a pupal stage in their life cycle independently of the holometabolans. So my problem with the slogan 'Holometabolous before it was cool' is not with the use of the word 'holometabolous'.

It's with the word 'before'. The earliest known crown-group thrips, and thus the earliest known thrips that we can be reasonably certain was holometabolous (absent actual fossilised thrips pupae) is Liassothrips crassipes from the Late Jurassic (Shmakov 2008). In contrast, the earliest known crown-group holometabolans are stem-beetles and stem-neuropterans from the Early Permian, a good hundred million years or so before (Grimaldi & Engel 2005). Even if we open the gates to potential stem-group thrips (which may or may not have been holometabolous), that doesn't take us back any further than a potential tie with the Holometabola.

Liassothrips crassipes, from Schmakov (2008). Scale bar equals 1 mm.

So while thrips may be holometabolous, the possibility that they were so 'before it was cool' is fairly remote. Thrips are much more likely to have been late-comers to the holometaboly game.

REFERENCES

Grimaldi, D., & M. S. Engel. 2005. Evolution of the Insects. Cambridge University Press.

Shmakov, A. S. 2008. The Jurassic thrips Liassothrips crassipes (Martynov, 1927) and its taxonomic position in the order Thysanoptera (Insecta). Paleontological Journal 42 (1): 47-52.

Catalogue of Organisms on Twitter

noreply@blogger.com (Christopher Taylor) — Wed, 05 Jun 2013 07:26:00 +0000

Ok, so I've finally opened an account on Twitter, about five years after it was a Thing. For those looking, I can be found at @CatOfOrg.

Book Review: The World's Rarest Birds, by Erik Hirschfeld, Andy Swash and Robert Still

noreply@blogger.com (Christopher Taylor) — Tue, 04 Jun 2013 06:06:00 +0000

The World's Rarest Birds is a fairly self-explanatorily named new book from Princeton University Press, a copy of which was recently forwarded to me to review. Published under the auspices of the conservation group BirdLife International, this book aims to provide information on every one of the world's 650 (or so) endangered bird species. To gather material for this, we are told, an international photography competition was held, and the book features mostly new photographs of nearly 600 bird species. Only 76 of the species covered could not be illustrated by photographs, and all of these have been represented with paintings by the artist Tomaz Cofta. And the results are...well, just take a look at this:

This is an incredibly handsome book. Every page just absolutely pops with colour, a veritable kaleidoscope of flight and feathers. Hours could be spent contemplating the images presented. A mass of red-breasted geese take flight on page 51, a pair of Bali starlings imitate gossiping suburban housewives on page 10, a Laysan duck strides amongst a flurry of flies on page 186, and a gloriously draggy bare-necked umbrellabird sneers at the camera on page 247. The images are crisp and clear, and accompanied by authoritative text. Nor does the book drop the ball any with the individual species accounts:

Every species receives a representative illustration and a quick rundown of status, estimated population, primary threats (represented by codes explained in the introduction to the book) and distribution map, though in the case of population estimates the choice of model can make some seem a little spuriously precise (such as the estimated 2090 Uvea parakeets). A red or green arrowhead against each species allows the reader to see at a glance whether a species' population has been declining or recovering (sadly, all the examples in the spread above are declining). A brief blurb provides specific information, most commonly a further rundown of the primary threats. Each species also has a barcode that is supposed to take the reader directly to that species' page on the BirdLife International website where more extensive information is available (not having the necessary features on my phone, I wasn't able to test this myself). The book and species accounts are divided into sections by continental mass; where a migratory and/or wide-ranging species can be regularly found in more than one continent, it is represented in multiple sections.

The real highlights of the book, in my opinion, are a number of sections covering more overarching topics: particular geographic regions (as in the example above), or particular groups of conservation interest such as bustards, vultures, or migratory birds. These provide a more synthetic view of the challenges, pressures, and occasionally conflicting interests affecting conservation around the world. However, it is also with these sections that one wonders how well the book is achieving its stated goal of advocacy. There are few images in the book other than those of birds, and I personally feel that the summary sections would have been a suitable place for some pictures more directly conveying the threats involved. A few well-placed photos of land clearance, grazing damage, or hunting snares may have sharpened this book's impact.

My other complaints are fairly minor. Some of the photos chosen to illustrate species accounts may have benefited from captions clarifying details such a whether the individual(s) shown is male or female, or where the photo was taken. The text's practice of consistently capitalising terms referring to formal conservation categories such as 'Endangered', 'Critically Endangered' or 'Extinct in the Wild' together with vernacular names, and of insistently providing the conservation status of each species when mentioned (never just 'the White-backed Vulture', but 'the Endangered White-backed Vulture'), can feel a bit heavy-handed at times. It can be hard not to read certain sentences as if Punctuated. For. Emphasis.

There is also the question of price. In an ideal world, one would not quibble at paying for quality, but sadly this world is not ideal. And so, having seen how much this book is awash with colour, how much effort has evidently gone into compiling it, it is with trepidation that we ask: how much?

And as it turns out, the list price is just $45 US. So if nothing else, the price of admission alone makes this worth it.

Quick Quiz

noreply@blogger.com (Christopher Taylor) — Mon, 03 Jun 2013 13:47:00 +0000

Recently, this has been seen doing the rounds on the interweb:

My first thought: clever. My second thought: hang on, there's something wrong here. Anyone care to guess what it was?

The Stone Mantis

noreply@blogger.com (Christopher Taylor) — Mon, 03 Jun 2013 06:01:00 +0000

Lithomantis carbonarius, as illustrated by Woodward (1876).

In 1876, Henry Woodward published the description of a large fossil insect found in a Scottish clay-ironstone nodule. This insect, when alive, would have had a wingspan of well over ten centimetres: Woodward measured the longest preserved wing at two and a quarter inches long, and a sizeable piece of the end was still missing. Believing it to be an ancient relative of the modern mantids, he named it Lithomantis carbonarius, the 'stone mantis from a coal measure'. Woodward's interpretation of his new fossil was to prove incorrect: it was not a mantis, but a member of those spectacular wonders of the Palaeozoic, the palaeodictyopteroids. More specifically, Lithomantis has been placed in a group of palaeodictyopteroids distinguished by Sinitshenkova (2002) as the Eugereonoidea.

Reconstructed wings of Lycocercus goldenbergi from Kukalová (1969), showing the overlap between the fore and hind wings; note also the bold colour patterning (often preserved in insect wings).

The palaeodictyopteroids are a group long overdue a truly comprehensive revision, and many aspects of their higher classification remain debatable. Of the current default classification, that of Sinitshenkova (2002), Prokop & Nel (2004) somewhat snarkily commented that, "Sinitshenkova’s classification cannot be considered based on the cladistic method, even if it uses the cladistic terminology". Nevertheless, Sinitshenkova defined the Eugereonoidea by a number of wing characters: wings that were about 2.5 times as long as broad, a subcostal vein reaching the costal vein near the wing apex, medial and cubital veins with little-branched anterior forks but much-branched posterior forks, and a tendency for the archedictyon (the net-like array of veinlets running amongst the major wing veins in palaeodictyopteroids) to become simplified or replaced by direct cross-veins. Members of the Eugereonoidea are known from the Upper Carboniferous and Lower Permian (Sinitshenkova 2002; Prokop & Nel 2007) and, like other palaeodictyopteroids, would have inhabited tropical latitudes in life.

Wings of the eugereonid Peromaptera filholi, from Kukalová (1969).

Like other palaeodictyopteroids (and, indeed, many other Palaeozoic insect groups in general), Eugereonoidea are mostly known from fossils of the wings, but those that are more completely known are large-bodied insects with relatively long sucking beaks. One species, Eugereon boeckingi, had a beak over three centimetres long; that of Lithomantis was a bit more restrained at only just over one centimetre. They used these impressive weapons to attack the stems of the ferns and seed ferns of the time in search of sap. Other palaeodictyopteroids, including the eugereonoid Lycocercus goldenbergi (Kukalová 1969), had much shorter beaks, and would have probably fed from spores or seeds. Eugereonoids had fairly broad-based wings with the fore and hind pairs of wings originally little differing from each other. The pronotum bore well-developed paranotal lobes that have lead to descriptions of these insects as 'six-winged'; though the pronotal lobes could not actively flap in the manner of true wings, Wootton & Kukalová-Peck (2000) suggested that they were somewhat movable, and could have been used to stabilised pitch. In the family Lycocercidae, the two pairs of wings overlapped to a degree unknown in any living insects; in Notorhachis wolfforum, the forewings overlapped the hind wings almost entirely. As argued by Wootton & Kukalová-Peck (2000), these species would have flown quickly but with relatively little manouevrability, like insectoid turkeys. In contrast, members of the families Eugereonidae and Megaptilidae developed relatively long narrow forewings followed by shorter, broader hind wings. Like modern insects with comparable wing morphologies (such as bees and butterflies), members of these families probably beat the two pairs of wings in concert, and would have been more manoeuvrable compared to the lycocercids. However, with an estimated wingspan of over a foot, the eugereonoid Megaptilus blanchardi was by far the largest insect ever known to develop this mode of flying.

REFERENCES

Kukalová, J. 1969. Revisional study of the order Palaeodictyoptera in the Upper Carboniferous shales of Commentry, France part II. Psyche 76: 439-486.

Prokop, J., & A. Nel. 2004. A new genus and species of Homoiopteridae from the Upper Carboniferous of the Intra-Sudetic Basin, Czech Republic (Insecta: Palaeodictyoptera). European Journal of Entomology 101: 583-589.

Prokop, J., & A. Nel. 2007. New significant fossil insects from the Upper Carboniferous of Ningxia in northern China (Palaeodictyoptera, Archaeorthoptera). European Journal of Entomology 104: 267-275.

Sinitshenkova, N. D. 2002. Superorder Dictyoneuridea Handlirsch, 1906 (=Palaeodictyopteroidea). In History of Insects (A. P. Rasnitsyn & D. L. J. Quicke, eds) pp. 115-124. Kluwer Academic Publishers: Dordrecht.

Woodward, H. 1876. On a remarkable fossil orthopterous insect from the coal-measures of Scotland. Quarterly Journal of the Geological Society of London 32: 60-65.

Wootton, R. J., & J. Kukalová-Peck. 2000. Flight adaptations in Palaeozoic Palaeoptera (Insecta). Biol. Rev. 75: 129-167.

The Mites of Springs

noreply@blogger.com (Christopher Taylor) — Thu, 30 May 2013 05:58:00 +0000

The Euroepan groundwater-inhabiting Stygohydracarus subterraneus, from here.

Arachnids might not normally be thought of as aquatic animals, but there are a number of arachnid lineages that have taken up a wetter way of life. Among these, it should come as no surprise that a number of them can be found among the mites, because mites are everywhere*
. The Athienemanniidae, the subject of today's post, are a family in one of the most diverse lineages of aquatic mites, the Hydrachnidia.

*Including on you. Right now.

Hydrachnidians are themselves one of the major subgroups of the mite lineage known as the Parasitengonina (briefly referred to in this post). The larval stage of the Parasitengonina, as the name of the group suggests, are parasitic on other animals, while the second nymphal and adult instars are free-living predators. Between each of these stages (i.e. at the first and third nymphal instars) is a non-feeding instar that could be thought of as a 'pupal' stage. As with an insect's pupal stage, parasitengoninans go through a significant physical transformation between stages (and I'm not just talking about the addition of an extra pair of legs between larva and nymph—all mites do that). Mature hydrachnidians are often heavily sclerotised, but larval hydrachnidians (like female ticks) are soft and membranous around the sides so they can swell up full of their host's internal juices.

A North American spring mite, Chelomideopsis besselingi, photographed by I. M. Smith.

The Athienemanniidae are one of the smaller mite families, with only fourteen currently recognised genera (Walter et al. 2009). Distinctive features of the family include a dorsoventrally flattened capitulum (the 'head-like' region of the animal incorporating the chelicerae and the pedipalps) and a rotated pedipalp, with the tarsus (the terminal segment) not visible from the side. The lifestyle of most athienemanniids remain little studied, but where known the larvae are parasites of midge larvae (for reasons about to become clear, this is probably not the case for all species). A number of species of Athienemanniidae are found in streams and springs, but the family is also diverse in the hyporheic zone, the region of sediment beneath and alongside streams where the water contained in the stream mixes with the groundwater. With their flattened, armoured bodies, athienemanniids would be well suited for crawling among the pockets of water between sand and gravel grains. There are also a number of species that have become adapted to live in the groundwater itself and may be found deep below the surface.

Despite the relatively small number of recognised species, the Athienemanniidae have been divided between four subfamilies. The great majority of species belong to the Athienemanniinae, which is also the most widespread subfamily. Species of Athienemanniinae are known from surface to ground waters in Eurasia, Africa and North America, and a single species Anamundamella zelandica is known from groundwater in New Zealand. The other subfamilies all contain small numbers of species in more restricted areas. The genera Stygameracarus and Africasia are each placed in their own subfamily; Stygameracarus is found in hyporheic gravels in North America, and Africasia in streams in southeastern Eurasia and tropical Africa (Walter et al. 2009). The subfamily Notomundamellinae contains four genera found in hyporheic gravels in Australia (Smit 2007).

The world diversity of Athienemanniidae is undoubtedly underestimated, perhaps significantly so. Sampling hyporheic and groundwater habitats can be a difficult process, and species found in these habitats generally exist at very low population densities. Even sampling previously productive localities may not be guaranteed to yield a result (Smit [2007] named one of the Australian athienemanniid species Janszoonia difficilis because of the difficulty in collecting the type specimen). And even if you do find them, you still have to wonder what it is that they're finding to eat down there.

REFERENCES

Smit, H. 2007. New records of hyporheic water mites from Australia, with a description of two new genera and ten new species (Acari: Hydrachnidia). Records of the Australian Museum 59: 97-116.

Walter, D. E., E. E. Lindquist, I. M. Smith, D. R. Cook & G. W. Krantz. 2009. Order Trombidiformes. In: Krantz, G. W., & D. E. Walter (eds) A Manual of Acarology, 3rd ed., pp. 233-420. Texas Tech University Press.

Porcelain Fans

noreply@blogger.com (Christopher Taylor) — Thu, 23 May 2013 07:22:00 +0000

Mature specimen of Rhapydionina deserta, from Loeblich & Tappan (1964).

Calcareous foraminiferans have been featured on this site before: planktic floaters, living stars, microscopic jelly moulds and gigantic reef-formers. All these forms have belonged to the group of calcareous forams known as the rotaliids. Today's subject is another group of forams, the Rhapydionininae, belonging to a different calcareous group, the Miliolida. Miliolids may have shell walls made of calcite like the rotaliids, but differ in the wall structure: while the walls of rotaliids are glass-like and porous, those of miliolids are structured like porcelain. Phylogenetic studies of forams have not placed the miliolids close to the rotaliids, and the two groups seem to have evolved their secreted shells independently (Sen Gupta 2002).

Rhapydionina liburnica, from Loeblich & Tappan (1964).

The Rhapydionininae were defined by Loeblich & Tappan (1964) as a group of miliolids with a conical test composed of broad chambers stacked one on top of another (the overall shape being kind of like a fan or an ice-cream cone), with each of these chambers subdivided by internal septa into multiple chamberlets (the difference between a 'chamber' and a 'chamberlet' being that the latter are not completely divided from each other by the walls). The opening of the test took the form of a sieve-like array of pores at the top end. However, subsequent researchers have discovered that Loeblich & Tappan's definition was inadequate. Rhapydioninines start life growing as a flat spiral, with growth becoming linearised at maturity. However, it turns out that not all Rhapydionininae become linear; some retain their juvenile coiling into maturity (Vicedo et al. 2011). At least some species are believed to have both a linear megalospheric form and a coiled microspheric form. To explain, forams can be divided between microspheric forms, in which the first chambers of a new test are much smaller, and megalospheric forms with larger initial chambers. In those relatively few forams whose life cycles have been studied in detail, these two forms correspond to an alternation of generations, with a mostly microspheric asexually-reproducing generation giving rise to the generally megalospheric sexually-reproducing phase. Loeblich & Tappan's (1964) concept of rhapydionines, therefore, would have potentially placed members of a single species into separate families.

Diagram of internal structure of two adult chambers of Cuvillierinella, from Vicedo et al. (2011). Key to abbreviations: ap f = apertural face, c chl = cortical chamberlets, flo = floor, m chl = medullar chamberlet, prp = preseptal space, rpi = residual pillars, s = septum, sl = septulum.

Rhapydionines are best known as fossils, with a definite range from the Upper Cretaceous to the mid-Eocene (Loeblich & Tappan 1984). Believe it or not, whether there are still rhapydioninines in the world is something of an open question. Loeblich & Tappan (1964) listed two Recent genera in the Rhapydionininae, each represented by only a single known specimen. Ripacubana conica was originally described from sand deposits in Cuba; however, Loeblich & Tappan (1964) suggested that Ripacubana may actually represent what has been referred to as a 'zombie taxon'. Some of you may be familiar with the palaeontological concept of a 'Lazarus taxon', where a species disappears from the fossil record only to reappear at a later date. What has actually happened in these cases is that the species had only become locally extinct, but survived in some other locality that has not been preserved, subsequently recolonising its old range. A 'zombie taxon', however, is one that has genuinely become extinct at the earlier date, but its fossilised remains have since been transported into a younger sediment deposit, giving the impression that it survived later than it did*. In the case of Ripacubana, it is difficult to know just how long a foram shell buried in sand has been lying there.

*Identifications of Lazarus taxa also have to be on the look-out for 'Elvis taxa': where the more recent population does not in fact represent the same species, but a different species that has convergently evolved similar features.

Craterites rectus, from Loeblich & Tappan (1964).

Loeblich & Tappan (1964) did not express the same reservations about Craterites rectus, described from a beach on Lord Howe Island east of Australia. Craterites was later separated as its own subfamily by Loeblich & Tappan (1984) on the basis of its being attached to the substrate, and so differing from other free-living Rhapydionininae. Nevertheless, they kept the two subfamilies together as the family Rhapydioninidae, so Craterites may still be the only known survivor of the rhapydioninine lineage. However, with only one known specimen, the details of the internal structure of Craterites remain unknown.

REFERENCES

Loeblich, A. R., Jr & H. Tappan. 1964. Treatise on Invertebrate Paleontology pt C. Protista 2. Sarcodina, chiefly "thecamoebians" and Foraminiferida, vol. 1. The Geological Society of America and The University of Kansas Press.

Loeblich, A. R., Jr & H. Tappan. 1984. Suprageneric classification of the Foraminiferida (Protozoa). Micropaleontology 30 (1): 1-70.

Sen Gupta, B. K. 2002. Modern Foraminifera. Springer.

Vicedo, V., G. Frijia, M. Parente & E. Caus. 2011. The Late Cretaceous genera Cuvillierinella, Cyclopseudedomia, and Rhapydionina (Rhapydioninidae, Foraminiferida) in shallow-water carbonates of Pylos (Peloponnese, Greece). Journal of Foraminiferal Research 41 (2): 167-181.

The Wool Plants

noreply@blogger.com (Christopher Taylor) — Wed, 22 May 2013 06:02:00 +0000

Vegetable lamb, as illustrated in The Travels of Sir John Mandeville (ca 1360).

Medieval legend in Europe spoke of a strange animal that could supposedly be found far off in central Asia: the vegetable lamb. According to legend, this was an animal much like an ordinary sheep except that it grew directly from a plant, to which it remained attached by the umbilical cord. The vegetable lamb would sustain itself by grazing on nearby vegetation but when this was depleted, as the lamb could not move away from the plant to which it was attached, the lamb would die. How such a pointlessly self-defeating organism was supposed to persist does not appear to have concerned the medieval lexicographers; presumably it was supposed to be allegorical of something.

Opening fruit of Gossypium hirsutum, photographed by B. P. Schuiling.
Part of the reason for the legend's persistence, however, was that there was indeed a form of 'wool' that came from a plant: cotton. The cotton genus Gossypium comprises about fifty species found in tropical and subtropical regions around the world (Wendel et al. 2010). Members of the genus vary from herbaceous perennials to small trees. The genus is divided into four subgenera, most of which are geographically distinct. The subgenus Gossypium is found in Africa and Arabia, subgenus Sturtia in Australia, and subgenus Houzingenia in the Americas. These three subgenera between them include the diploid cotton species; the fourth subgenus Karpas is also found in the Americas but differs in containing tetraploid species. Genetic evidence indicates that the subgenus Karpas arose at some point in the very recent past (within the last one or two million years) from a single hybridisation event between a species of subgenus Gossypium and one of Houzingenia, probably as a result of some chance dispersal event from Africa. Gossypium seeds seem well suited to dispersal: seeds of the Hawaiian Island species G. tomentosum have apparently germinated after being kept immersed in artificial seawater for three years (Wendel et al. 2010)! This same predicection for dispersal has resulted in the tetraploid species rapidly becoming widespread despite their recent origin, and in producing two species in remote locales: the Hawaiian G. tomentosum is directly related to the mainland G. hirsutum, while the Galapagos G. darwinii is sister to the mainland G. barbadense.

Levant cotton Gossypium herbaceum, photographed by H. Zell.

Commercial cotton is grown from four species of Gossypium, which may have each been domesticated independently in prehistoric times. All Gossypium species produce seeds with a covering of fuzzy hairs, but seeds of the two Old World diploid species G. herbaceum and G. arboreum also possess an outer layer of longer, flatter hairs that can be woven into thread. It was one of these two species, or possibly some now-extinct close relative, that made the crossing over the Atlantic to become one ancestor of the tetraploid species; as a result, the tetraploid species also possess these long outer hairs. Two of the tetraploid species, G. barbadense and G. hirsutum, were also domesticated, and the latter of these is now by far the most abundant cotton species in cultivation*.

*In case you were wondering, no-one seems to have suggested that the island species related to the two American domesticates might have been human-dispersed.

Sturt's desert rose Gossypium sturtianum, from here.

Other diploid Gossypium species do not possess this longer outer hair layer, only the inner short layer, and are not sources of commercial cotton (though hybrids with some of these species have been used to breed desirable genetic traits into the commercial species). In one group of Australian species (the section Grandicalyx) found in the Kimberley region of northern Western Australia, the hair layer has become very sparse and the seeds are almost hairless. These seeds also possess fatty bodies called eliosomes that are attractive to ants, and the plants are dispersed by having hungry ants carry their seeds away. Grandicalyx species are seasonal herbs, dying off above ground during droughts only to resprout from their thick root-stock. Other Australian species include the Sturt's desert rose Gossypium sturtianum, the floral emblem of Australia's Northern Territory.

Gossypium gossypioides, from here.

As with other plant groups, hybridisation appears to have been a recurring factor in the evolution of Gossypium. The diploid Gossypium species have been divided between eight genome groups, hybrids between which are generally not viable (though not unknown: the parents of the tetraploid lineage, for instance, belonged to separate groups). However, genetic studies of some Gossypium species have identified discrepancies where a species may possess the nuclear genome of one group, but the chloroplast genome of another. For instance, the North American species G. gossypioides resembles other New World species in its nuclear genome, but has chloroplasts related to those of G. herbaceum or G. arboreum (which it may have acquired as a result of the same hybridisation event that produced the tetraploid species*). This phenomenon, which has been called cytoplasmic introgression, may have arisen in cotton through a process called semigamy. Semigamy is a particular form of apomixis (reproduction without fertilisation) in which sperm and egg cells fuse cytoplasmically, but their nuclei remain distinct (Curtiss et al. 2011). These nuclei will eventually be segregated by cell division, resulting in offspring that are mosaics of male- and female-line genomes. Over time, selection or drift may produce a homogenous population that retains the nuclear genome of one ancestor, but the cytoplasmic heritage of the other.

*The American parent of the tetraploids has more usually been identified as G. raimondii, a South American species, but G. raimondii is the direct sister species of G. gossypioides. It may be that G. gossypioides is the true parent of the tetraploids, or it may be that it too is derived from G. raimondii or its parent stock).

REFERENCES

Curtiss, J., L. Rodriguez-Uribe, J. McD. Stewart & J. Zhang. 2011. Identification of differentially expressed genes associated with semigamy in Pima cotton (Gossypium barbadense L.) through comparative microarray analysis. BMC Plant Biology 11: 49.

Wendel, J. F., C. L. Brubaker & T. Seelanan. 2010. The origin and evolution of Gossypium. In: Stewart, J. McD., D. Oosterhuis, J. J. Heitholt & J. R. Mauney (eds) Physiology of Cotton pp. 1-18. Springer.

Riroriro

noreply@blogger.com (Christopher Taylor) — Mon, 06 May 2013 04:42:00 +0000

The grey warbler or riroriro Gerygone igata, photographed by Peter Bray.

The eighteen recognised species of the genus Gerygone are an assemblage of small, drab-coloured birds found mostly in the Australo-Papuan region, with G. sulphurea found in the Malay Peninsula, Indonesia and the Philippines, and G. flavolateralis found in New Caledonia and Vanuatu. These are another group of birds that have tended to draw the short straw in the vernacular name stakes: G. igata, one of the most abundant of New Zealand's native birds, is usually identified by the uninspiring 'grey warbler'. Personally, I prefer the more onomatopoeiac Maori name for these lively little birds: 'riroriro' (it has been suggested in some circles that it could possibly be referred to as the 'grey gerygone'; this proposition shall be treated with the scorn that it deserves). The riroriro and its congeners feed on small insects that they mostly glean from leaves or small branches, generally in the middle to upper canopies (Ford 1985). A certain amount of their prey is caught in the air, while the riroriro and the brown warbler G. mouki of eastern Australia also forage in lower vegetation than other species. The riroriro is also the only Gerygone species known to forage on the ground (Keast & Recher 1997).

Gerygone species build hanging purse-shaped nests; this is a brown warbler Gerygone mouki photographed by Peter.

Somewhat unusually for a decently-speciose passerine genus, the circumscription of Gerygone has been fairly stable in recent years, and the genus has mostly been supported as monophyletic. The only exception of recent times has been the New Guinean G. cinerea, recently reclassified by Nyári & Joseph (2012) as a species of Acanthiza. In the early 1900s, some authors divided Gerygone species between smaller genera (for instance, the Australian ornithologist Gregory Mathews, who never met a genus he couldn't break down). One species so separated was the Chatham Island warbler G. albofrontata, which is something of an island giant compared to other Gerygone species, weighing about 12 g while other species are about 6 to 7 g (Keast & Recher 1997). Unfortunately, the Chatham Island warbler was not included in the phylogenetic analysis of Gerygone by Nyári & Joseph (2012), but it was not identified as significantly separate from other Gerygone species in the morphological analysis by Ford (1985).

The Chatham Island warbler Gerygone albofrontata, from here.

REFERENCES

Ford, J. 1985. Phylogeny of the acanthizid warbler genus Gerygone based on numerical analyses of morphological characters. Emu 86: 12-22.

Keast, A., & H. F. Recher. 1997. The adaptive zone of the genus Gerygone (Acanthizidae) as shown by morphology and feeding habits. Emu 97: 1-17.

Nyári, Á. S., & L. Joseph. 2012. Evolution in Australasian mangrove forests: multilocus phylogenetic analysis of the Gerygone warblers (Aves: Acanthizidae). PLoS One 7(2): e31840.

Into the Labyrinth

noreply@blogger.com (Christopher Taylor) — Mon, 29 Apr 2013 07:34:00 +0000

Climbing perch Anabas testudineus emerging from water, as illustrated by Richard Lydekker.

Amongst the unholy mess that is the Percomorpha, one group that has long been recognised is the labyrinth fishes of the Anabantoidei. The anabantoids are a group of freshwater fishes found in southern Asia and Africa (but not Madagascar) that get their vernacular name from their possession of a distinctive respiratory organ called the labyrinth. This organ, found in a cavity above the gills, is derived from part of the first gill arch; the bone has become expanded and much-folded, and is covered with a layer of respiratory epithelium. So long as the gills do not actually dry out, the labyrinth allows these fish to take in oxygen directly from the air, and they can survive in warm, low-oxygen waters. They can even survive for limited periods entirely out of water (a feature that has helped make some of the larger species popular food fish, due to the greater ease of keeping them fresh in a tropical environment). Recent phylogenetic studies (e.g. Li et al. 2009) have agreed in placing labyrinth fishes as related to a number of other freshwater Indo-Australian fishes, such as the snakeheads of the Channidae and the swamp eels of the Synbranchidae, many of which are also tolerant of air-breathing.

Kissing gouramis Helostoma temminckii, from Peter Bus.

Labyrinth fishes can be divided between three families (Rüber et al. 2006). One of these contains a single species, the kissing gourami Helostoma temminckii of south-east Asia. Kissing gouramis are primarily specialised filter feeders, though they may also graze on algae or insects. The vernacular name refers to their enlarged lips, making them look permanently puckered up. Kissing gouramis even 'kiss', pressing their smackers against one another, though this is regarded as an act not of affection but of aggression (kind of like a 1930s Hollywood melodrama) as the fish push against one another.

A rather unfortunate Cape kurper Sandelia capensis, photographed by Darryl Lampert.

The climbing perches of the Anabantidae include the south Asian Anabas and the African Ctenopominae. These short-bodied carnivores have serrated edges to their gill covers that the Asian species use to pull themselves over land when travelling between water bodies (imagine lying on your stomach and pulling yourself along with your chin). You can see video of some climbing perch Anabas testudineus emerging from water here.

Giant gourami Osphronemus goramy, photographed by E. Naus.

The most diverse subgroup of the Anabantoidei is the gouramis of the Osphronemidae, another south Asian group. The largest of the Osphronemidae, the giant gourami Osphronemus goramy, grows up to 70 cm, but most species are quite a bit smaller. A number of gourami species (as well as the kissing gourami) are popular aquarium fishes; the most popular by far is the Siamese fighting fish Betta splendens, males of which have been bred to exhibit much longer and more ornamental fins than found in the wild. The gouramis are generally omnivorous, with species varying in the extent to which they prefer plant or animal food. The most specialised carnivore of the Osphronemidae is the pikehead Luciocephalus pulcher, a small but elongate species that has been described as having the most protrusible mouth of any fish (and that, by the way, is no small claim). You can see the pikehead in action below:

The pikehead is so divergent from other labyrinth fishes that past authors have regarded it as its own family, possibly the sister taxon to all other anabantoids, or even questioned whether it was a labyrinth fish at all. However, as confirmed by Rüber et al. (2006), Luciocephalus is not only a true anabantoid but nested well within the Osphronemidae as sister to the chocolate gouramis of the genus Sphaerichthys. These and two other genera, Ctenops and Parasphaerichthys, form what is known as the 'spiral egg' clade, named after the presence of spiraling ridges on the egg leading to the micropyle, that have been suggested to act as guides for the sperm.

Siamese fighting fish Betta splendens mating below a bubble-nest, photographed by Stephen & John Downer.

The anabantoids are also known for the bubble-nests constructed by a number of species, in which the eggs are contained within a floating nest of bubbles that is guarded by the male parent (both parents in the Ceylonese combtail Belontia signata). Bubble-nesting has evolved at least twice among the anabantoids: once in the Osphronemidae, and once in the ctenopomine genus Microctenopoma (other anabantids and Helostoma are free spawners that do not construct nests or guard their eggs; the ctenopomine Sandelia capensis digs a nest in the bottom substrate) (Rüber et al. 2006). Though bubble-nesting is probably the ancestral behaviour for Osphronemidae, it has been modified in a number of sublineages. Osphronemus species build submerged nests from vegetation, while members of the 'spiral egg' clade (except Parasphaerichthys) and a number of Betta species are mouthbrooders. Usually the male broods the fry in these species, but the female is the brooder in a couple of Sphaerichthys species.

REFERENCES

Li, B. A. Dettaï, C. Cruaud, A. Couloux, M. Desoutter-Meniger & G. Lecointre. 2009. RNF213, a new nuclear marker for acanthomorph phylogeny. Molecular Phylogenetics and Evolution 50: 345-363.

Rüber, L., R. Britz & R. Zardoya. 2006. Molecular phylogenetics and evolutionary diversification of labyrinth fishes (Perciformes: Anabantoidei). Systematic Biology 55 (3): 374-397.

The Kellyclams

noreply@blogger.com (Christopher Taylor) — Tue, 23 Apr 2013 04:56:00 +0000

Ruddy lasaeas Lasaea adansoni photographed in a rock crevice by David Fenwick.

Members of the family Lasaeidae, commonly known as kellyclams, are small thin-shelled bivalves that often live in close association with larger invertebrates such as crustaceans, worms or cnidarians. The clam may be directly attached to its host or share a burrow with it; one genus, Entovalva, includes associates of sea cucumbers that live within their host's esophagus (you can find some more details of this particular relationship here). Though the clam's presence may not be entirely without physical effect on its host, such effects are usually minor and kellyclams are generally regarded as commensals rather than parasites. Other species live independently and may live nestled among rocks or buried in sediment; these free-living forms may possess a relatively large muscular foot for mobility. Like most bivalves, kellyclams are filter feeders; the invertebrate-commensal species are believed to take advantage of water currents created by the host to increase the effectiveness of their own feeding currents.

Commensal Pseudopythina rugifera attached to a ghost shrimp Upogebia pugettensis, photographed by Arthur Anker.

The family-level classification of the kellyclams has been fairly turbulent. The family has variously been known as the Lasaeidae, Erycinidae or Leptonidae, owing to confusion over which of these names has priority, while some authors have regarded them as separate families and/or recognised further segregate families Kelliidae or Montacutidae. With their small size, kellyclams have simplified a number of the characters used in classifying other bivalves, and a number of the commensal species have become modified in order to co-exist with their host. The Peregrinamor species, for instance, live attached longitudinally underneath the thorax of the ghost shrimp Upogebia; they have accordingly become low and elongate, and were until recently misclassified as mussels of the Mytilidae (note that the Lasaeidae and Mytilidae represent evolutionary lineages that first diverged some time in the Ordovician). In the broad sense, the Lasaeidae have been separated from the closely related family Galeommatidae by the fact that members of the latter have the soft body enlarged so that the shell becomes internal. However, Goto et al. (2012) established that even this distinction is not reliable, with the Galeommatidae nested and probably polyphyletic within the Lasaeidae. Also, while Goto et al. did not support recognition of the Lasaeidae as a holophyletic group, nor did they support any of the segregate families. Commensal species are scattered phylogenetically among free-living species, and host-switching has apparently happened numerous times within commensal lineages.

The Lasaeidae are hermaphrodites, and often brooders. Rather than being released as eggs, young are retained within their parent until they are released as veligers (later-stage larvae that have begun to develop a shell) or as miniature versions of the adults.

REFERENCES

Goto, R., A. Kawakita, H. Ishikawa, Y. Hamamura & M. Kato. 2012. Molecular phylogeny of the bivalve superfamily Galeommatoidea (Heterodonta, Veneroida) reveals dynamic evolution of symbiotic lifestyle and interphylum host switching. BMC Evolutionary Biology 12: 172.

"Anatomy of Mollusca": A Case of Plagiarism

noreply@blogger.com (Christopher Taylor) — Mon, 22 Apr 2013 06:09:00 +0000

Whilst researching material for an upcoming post, I came across this book on Google Books, published in 2010 by the International Scientific Publishing Agency, New Delhi:

Anatomy of Mollusca, by Rita Rawat

Looking at the section previewed through Google Books, I couldn't help feeling that it seemed a little... familiar. Take a look at this screenshot from Google Books:

Now take a look at this screenshot, taking from a page written by my erstwhile associates at Palaeos.com, last modified in 2006:

I can only go by what was available in the Google Books preview, of course, without direct access to the actual book, but I can confirm that most if not all of the material in pages 15 to 72 at least of the "Anatomy of Mollusca" appears to have been copied directly from Palaeos.com (unfortunately, a large part of Palaeos.com is currently offline as the site gets revamped). A quick Google search failed to uncover anything indicating whether the International Scientific Publishing Agency has a reputation for publishing lifted material, so I can't say if this is part of a broader issue.

Amazon currently has the "Anatomy of Mollusca" on sale for just over $75. Not that expensive by the standards of technical publications, but a fair chunk of change by the standards of books in general. Certainly a lot more than the cost of reading the same stuff on Palaeos.com, which carries no extra cost beyond that of the ISP charges.

Dung Beetles

noreply@blogger.com (Christopher Taylor) — Wed, 17 Apr 2013 05:26:00 +0000

Flat-headed dung beetles Pachylomerus femoralis with a ball of the good stuff, photographed by Guido Coza.

The dung beetles of the Scarabaeini include 146 species found in Africa and Asia, classified by Forgie et al. (2006) into three genera: Pachysoma, Pachylomerus and Scarabaeus, with the last including the vast majority of species. The Scarabaeus species are perhaps the most famous of all dung beetles, renowned since ancient history when Egyptians saw a dung beetle rolling a ball of dung along the ground as a metaphor for the movement of the sun through the heavens*. Dung beetles collect their turd balls to use as food for themselves or for their larvae. Ball-rolling is not unique to the Scarabaeini as a method of transporting dung, however (it is also done by members of other dung beetle tribes), nor do all Scarabaeini species engage in ball-rolling.

*It probably does not say much for the standard of ancient Egyptian public sanitation that they were apparently so willing to believe that the ultimate source of all life on the planet was a giant mass of burning poop.

Flightless orange dung beetle Pachysoma denticolle, photographed by Alex Dreyer.

The flightless dung beetles of the genus Pachysoma, for instance, transport their food by dragging it along between their hind legs. Pachysoma species are also less choosy than other Scarabaeini, feeding not just on dung but all manner of organic detritus. They have specialisations allowing them to feed on drier food particles than other Scarabaeini, suitable for their arid habitats in southern Africa. In contrast, species of the subgenus Sceliages within Scarabaeus are the epicures of the scarabaein world: they feed entirely on dead millipedes, which they push along in front of themselves bulldozer-style (Forgie et al. 2005). Relatively few species of Scarabaeini feed by burrowing directly alongside piles of dung where they lay, but this may be done by Pachylomerus and Scarabaeus galenus (both of which may also transport food).

Individual of Sceliages transporting a millipede, photographed by Shaun Forgie.

Most Scarabaeini are active during the day, but a small number such as Scarabaeus satyrus are nocturnal in habit. In the phylogenetic analyses conducted by Forgie et al. (2005), these nocturnal species usually formed a single clade. Had the ancient Egyptians observed the nocturnal dung beetles as well, they could have presented us with a sky full of poo at all hours.

REFERENCES

Forgie, S. A., U. Kryger, P. Bloomer & C. H. Scholtz. 2006. Evolutionary relationships among the Scarabaeini (Coleoptera: Scarabaeidae) based on combined molecular and morphological data. Molecular Phylogenetics and Evolution 40: 662-678.

Forgie, S. A., T. K. Philips & C. H. Scholtz. 2005. Evolution of the Scarabaeini (Scarabaeidae: Scarabaeinae). Systematic Entomology 30: 60-96.

Snap! goes the Termite

noreply@blogger.com (Christopher Taylor) — Tue, 16 Apr 2013 06:07:00 +0000

The snapping termite Cavitermes tuberosus, from Wiki Termes.

For the subject of today's post, I drew the termite subfamily Termitinae. Termites are extraordinary animals: socially complex, ecologically vital, dietically remarkable. Personally, I'm rather found of these communal cockroaches.

Termites of the family Termitidae (commonly referred to as the 'higher termites') differ from other, 'lower' termites in the nature of their gut biota (without which they would not be able to digest their cellulose diets): instead of having flagellated protozoa in their gut, termitids carry symbiotic bacteria. This difference in symbionts is reflected by a difference in diet. Higher termites feed on more decayed wood or plant matter than lower termites; some higher termites feed directly on organic-rich soil that contains little or no plant material (Inward et al. 2007). Subfamilies within the Termitidae are also distinguished on the basis of their gut anatomy: members of the Termitinae have what is called a 'mixed segment' on the outer edge of their intestine (Lo & Eggleton 2011). In the mixed segment, instead of the division between the mesenteron (the middle section of the intestine) and the proctodaeum (the posterior section) being simple and straight across, the mesenteron wall extends backwards along one side of the gut only; it has been suggested that the mixed segment functions to pump alkaline fluids into the gut, maintaining appropriate pH and fluid levels for the symbiotic bacteria in the hindgut (Bignell et al. 1983).

Workers of Amitermes dentatus repairing a damaged nest, from here.

The Termitinae have also been distinguished on the basis of the morphology of their soldiers, with most genera having soldiers with elongate mandibles that have relatively few large teeth. These are used to bite and slash at threats to the colony. However, phylogenetic analyses have contradicted this distinction (Inward et al. 2007). The Termitinae are paraphyletic with regard to the Nasutitermitinae, who have developed a very different method of defense: the mandibles are reduced, and instead the front of the head is drawn out into an elongate 'nose'. At the end of the 'nose' is a glandular opening from which the soldiers squirt a sticky glue at their opponents. Also nested within the Termitinae are the Syntermitinae whose soldiers combine both methods of defense: they retain sickle-shaped mandibles that are used to pierce the cuticle of attackers while the protruded glandular opening is used to apply toxic secretions. Chemical defenses are also not unknown among more standard termitines: soldiers of Globitermes sulphureus were dubbed 'walking bombs' by E. O. Wilson due to their explosive (and often self-destructive) discharge of toxic chemicals from hypertrophied labial gland reservoirs in the abdomen. It should also be noted that a small number of termitines do not produce soldiers at all: they may live in association with other soldier-producing termites, like the Australian Invasitermes, or they may feed on low-nutrient soils (presumably making the maintenance of a soldier caste too nutritionally expensive), like the Indomalayan genera Protohamitermes and Orientotermes.

The mushroom-like mound of Cubitermes, a major soil-feeding genus in Africa, photographed by Marco Schmidt.

Another mode of defense that is found only among the termitines (though phylogenetic analysis indicates that it has evolved multiple times) is the production of soldiers with elongate snapping mandibles. In these termites, soldiers store kinetic energy through muscular deformation of the mandibles, allowing them to be suddenly closed with great force (Prestwich 1984). So great is the force involved, in fact, that it seems to be not uncommon for the jaws to become completely crossed over as has happened to the individual at the top of this post. Snapping termites generally live in subterranean colonies, and even after the soldier has been 'spent' on the discharge of its mandibles, its body acts as a physical barrier in the confined tunnel. In some snapping termites, the mandibles are strongly asymmetrical, so the force of the closure is channelled through the left mandible only with doubled force. Asymmetrical snappers of the genus Neocapritermes, in fact, are able to knock out fairly large ants with a single blow. The video below shows a soldier of Planicapritermes attacking an ant: Or you can see Neocapritermes in action in this video. Keep a close eye on the screen around the 20-second mark...

REFERENCES

Bignell, D. E., H. Oskarsson, J. M. Anderson & P. Ineson. 1983. Structure, microbial associations and function of the so-called "mixed segment" of the gut in two soil-feeding termites, Procubitermes aburiensis and Cubitermes severus (Termitidae, Termitinae). Journal of Zoology 201: 445-480.

Inward, D. J. G., A. P. Vogler & P. Eggleton. 2007. A comprehensive phylogenetic analysis of termites (Isoptera) illuminates key aspects of their evolutionary biology. Molecular Phylogenetics and Evolution 44: 953-967.

Lo, N., & P. Eggleton. 2011. Termite phylogenetics and co-cladogenesis with symbionts. In: Bignell, D. E., et al. (eds) Biology of Termites: a modern synthesis pp. 27-50. Springer.

Prestwich, G. D. 1984. Defense mechanisms of termites. Annual Review of Entomology 29: 201-232.

Nosybelba: A Uniquely Madagascan Mite

noreply@blogger.com (Christopher Taylor) — Wed, 03 Apr 2013 06:20:00 +0000

Dorsal and ventral views of the main body of Nosybelba oppiana, from Mahunka (1994).

Why yes, it's another random oribatid! Nosybelba oppiana was described from Madagascar by Sándor Mahunka in 1994; Mahunka regarded it as distinct enough from other oribatids that he placed it in its own monospecific family. To date, the original description appears to be the sum total of our knowledge of Nosybelba oppiana. Subías et al. (2012) transferred it to a separate subfamily within the larger family Oppiidae, and transferred a second Madagascan species 'Oppia spinipes' Balogh 1964 to Nosybelba, but this was in the context of a species checklist only without supporting discussion (also, the name Oppia spinipes was used for an oribatid species by Banks in 1906, so whatever the status of Balogh's species it needs a new name).

Leg I of Nosybelba oppiana, from Mahunka (1994). Femur and genu of the right, tibia and tarsus on the left.

So what can we tell about Nosybelba from its description? One of the first things that attracts attention is that it has rather weird legs. The tarsi (the terminal segments) of the legs are really short, shorter on all legs than the adjoining tibia. On the first pair of legs, the tarsus is also compressed longitudinally, and a dorsal process on the tibia (that bears a large sensory seta) overhangs the tarsus. To my admittedly uneducated eyes, the overall structure does not give an impression of mobility. I'm guessing that Nosybelba is not the most agile of oribatids. At the end of each leg is a single large claw; as mentioned in a previous post, the number of claws on an oribatid's legs tends to correlate with habitat, with single claws suggesting a terrestrial lifestyle.

Lateral view of front end of Nosybelba oppiana (minus legs), from Mahunka (1994).

Another noteworthy feature of Nosybelba can be found in its mouthparts. The mentum, the 'under-head' shelf that underlies the chelicerae, does not have a basal articulation, so the chelicerae are limited in their range of movement. The chelicerae themselves do not have any teeth, so Nosybelba is not feeding on anything that requires a great deal of processing before swallowing. In another oribatid family, the Suctobelbidae, similar chelicerae are related to a diet of plant matter that is in an advanced state of decay; Nosybelba is presumably also a connoiseur of the rotten and the liquefied.

REFERENCES

Banks, N. 1906. New Oribatidae from the United States. Proceedings of the Academy of Natural Sciences of Philadelphia 58 (3): 490-500.

Mahunka, S. 1994. Oribatids from Madagascar II. (Acari: Oribatida). Revue Suisse de Zoologie 101 (1): 47-88.

Subías, L S., U. Ya. Shtanchaeva & A. Arillo. 2012. Listado de los ácaros oribátidos (Acariformes, Oribatida) de las diferentes regiones biogeográficas del mundo. Monografías electrónicas S.E.A. 4.

Acervulinids: Reef Forams

noreply@blogger.com (Christopher Taylor) — Thu, 21 Mar 2013 09:39:00 +0000

Regular readers of this site will know that, contrary to common belief, not all representatives of the vaguely defined category of organisms known as 'protozoa' are too small to be seen with the naked eye. Some are very visible indeed, and many of the more visible forms can be found among the shell-constructing amoeboids known as Foraminifera. One group of giant forams, the xenophyophores, has become fairly famous in internet circles as one of the contenders for the title of 'largest single cell', though, as noted in the post linked to, the question is kind of a pointless one with regard to forams. Besides, as described later in this post, xenophyophores may not have even have always been the largest forams.

Encrusting nodules of Acervulina inhaerens from Rhodes, from M. Hesemann.

The Acervulinidae are a family of reef-inhabiting forams belonging among the rotaliids. Juvenile chambers of newly growing acervulinids are arranged in a flat spiral, but chambers of mature specimens may be arranged in one to several layers. The chambers do not have regular apertures, and instead their walls are only pierced by coarse pores (Perrin 1994). Genera and species of acervulinids are distinguished by the presence, arrangement and shapes of layers and chambers, but defining distinctions appropriately is challenging. Acervulinids do not have a determinate 'adult morphology'; instead, the final adult appearance can be affected by factors such as substrate relief and water movement. Properly identifying acervulinids therefore requires identification of features independent of these external factors.

Living crust of Gypsina plana, photographed by Hal Ray Tichenor.
Acervulinids can be abundant on tropical coral reefs, and may play a not insiginificant role in reef formation as binding organisms. They tend to be particularly prominent in deeper parts of the reef, as they can tolerate lower light levels than other organisms such as coralline algae; in shallower parts of the reef, they are found in more cryptic locations among the coral. Acervulinids may be free-living, or they may be directly attached to their substrate. Like the star-shaped calcarinids, their primary food source is benthic diatoms (that they may or may not live with symbiotically), and the abrupt disappearance of the modern Acervulina inhaerens below depths of 130 m probably corresponds to the lower limit of that food source (Bosellini & Papazzoni 2003).

Fossilised nodules from a Solenomeris reef, photographed by Stefano Dominici. Note that Stefano identifies these as Acervulina; due to the complications in distinguishing acervulinid taxa, it remains contentious whether Solenomeris and Acervulina can be reliably separated.

Attached acervulinids may form either nodules or spreading crusts, depending on species and/or growth conditions (Perrin 1994). Such nodules or crusts may have diameters in the millimetre range, but some living species may be within the decimetre range. The most dramatic expression of acervulinid potential, however, was known from the Tethyan region during the Eocene period (the Tethys, for those unfamiliar with it, was the sea that connected the Atlantic and Indian Oceans north of Africa, before the northward movement of that continent closed off the Mediterranean at the eastern end). Here was found Solenomeris ogormani, initially interpreted as a red alga but since reidentified as an acervulinid. Solenomeris was primarily an encrusting form, but large growths would also produce tightly packed branches one or two centimetres in diameter. Over time, Solenomeris formed massive metre-sized domes, and these domes together would form entire reefs stretching over multiple kilometres: reefs formed not of coral, or of algae, but purely of forams!

REFERENCES

Bosellini, F. R., & C. A. Papazzoni. 2003. Palaeoecological significance of coral−encrusting foraminiferan associations: a case−study from the Upper Eocene of northern Italy. Acta Palaeontologica Polonica 48 (2): 279-292.

Perrin, C. 1994. Morphology of encrusting and free living acervulinid Foraminifera: Acervulina, Gypsina and Solenomeris. Palaeontology 37 (2): 425-458.

The Range of Lotus

noreply@blogger.com (Christopher Taylor) — Mon, 11 Mar 2013 05:26:00 +0000

For today's post, I'll be focusing on the lotus. And having said that, how many of you instantly thought of something like this:

To which I can only say: you should be ashamed of yourself. That is not a lotus, that is some wierd aquatic poppy-type thing called Nelumbo nucifera. This is a lotus:

Bird's-foot trefoil Lotus corniculatus, from Lyndon's Garden.

To clarify, Lotus is a genus of over a hundred species of herbaceous legumes native mostly to Eurasia and northern Africa, with smaller numbers of species in sub-Saharan Africa and Australia (Kirkbride 1999). About forty or so species have also been assigned to this genus from the Americas (particularly western North America), but all recent analyses have agreed that the New World species are not immediately related to the Old World species (Allan & Porter 2000; Arambarri et al. 2005) and they have been reclassified as genera Hosackia, Acmispon, Ottleya and Syrmatium—we shall not speak of them again. How the name 'lotus' came to be simultaneously applied to two such different plants as pictured above, I couldn't say, but the practice goes back a long time: the elder Pliny was referring to both sweet clover and a water lily as lotus in the first century AD (Kirkbride 1999). He also used the name 'lotus' for jujubes and (possibly) pomegranates, so he evidently had a certain affection for the word.

Greater lotus Lotus uliginosus, photographed by Forest & Kim Starr.

Lotus species are commonly known as trefoils, in reference to the leaves being divided into three leaflets. As it happens, most Lotus species actually have leaves with five leaflets, but two of those are separated from the others by an extended midrib. Pea-shaped flowers are borne in small terminal clusters; these are most commonly yellow, though some species produce red flowers. A few species have gone by the vernacular name of 'bacon and eggs' in reference to their producing flowers which are a combination of the two colours. Seeds are produced in long straight pods, and the appearance of the clustered pods is responsible for another vernacular name, bird's-foot trefoil. In one group of species, commonly separated as a genus Tetragonolobus but phylogenetically nested among other Lotus (Allan & Porter 2000), the pods bear four longitudinal wings. Even excluding the New World species, the exact number of species recognised in Lotus varies between authors, primarily due to disagreement over the appropriate treatment of segregates of the more widespread and variable taxa.

Young pod and flower of asparagus pea Lotus tetragonolobus, from here.
A number of Lotus species, particularly L. corniculatus and the greater lotus L. uliginosus*, are used as pasture legumes and have become established around the world as a result. Though arguably less productive than alternative legumes such as clover, they are often able to tolerate more marginal habitats (particularly waterlogged ground). Some species do contain secondary metabolites that can produce cyanide, but concentrations are not usually high enough to be a concern. The asparagus pea Lotus tetragonolobus (also known as Tetragonolobus purpureus) is grown for more direct human consumption, with the pods being eaten before they reach maturity. The name 'asparagus pea' is supposed to refer to their flavour, but this website expressed the opinion that: "If you have an excessively moist mouth, and are looking for something to suck all the moisture out and leave you all pasty, then asparagus peas are the vegetable for you."

*There seems to be some disagreement out there about whether Lotus uliginosus should be recognised as distinct from L. pedunculatus. Kirkbride (1999) uses L. uliginosus as a distinct taxon.

REFERENCES

Allan, G. J., & J. M. Porter. 2000. Tribal delimitation and phylogenetic relationships of Loteae and Coronilleae (Faboideae: Fabaceae) with special reference to Lotus: evidence from nuclear ribosomal ITS sequences. American Journal of Botany 87 (12): 1871-1881.

Arambarri, A. M., S. A. Stenglein, M. N. Colares & M. C. Novoa. 2005. Taxonomy of the New World species of Lotus (Leguminosae: Loteae). Australian Journal of Botany 53: 797-812.

Kirkbride, J. H., Jr. 1999. Lotus systematics and distribution. In: Trefoil: The Science and Technology of Lotus, pp. 1-20. Crop Science Society of America and American Society of Agronomy.

The Parulidae: Not-warblers, Not-ovenbirds and Not-redstarts

noreply@blogger.com (Christopher Taylor) — Mon, 04 Mar 2013 05:10:00 +0000

Black-crested warbler Myiothlypis nigrocristata, photographed by Mikko Pyhälä.

There is no denying the current status of English as the de facto lingua franca of the world*. And yet, I feel that a complaint must be laid at the feet of the Brits: they're a bit unimaginative when it comes to animal names. Many a British explorer, upon being presented with some hitherto unfamiliar product of the natural world, proceeded to label it with the name of whatever inhabitant of his native Europe he felt bore some vague resemblance. And hence, even today, there are significant groups of animals such as the Parulidae that are almost without a vernacular name to genuinely call their own.

*The potential irony of this sentence is not lost on me.

The Parulidae are a family of birds found throughout the Americas, though in the northern United States and Canada they are represented by migratory species that retreat further south in the cold months. Many of the migratory species have males with brightly coloured breeding plumage and are consequently idolised by North American bird watchers; non-migratory species, on the other hand, tend to have similarly subdued males and females (Update: see comments below). Members of the Parulidae are generally referred to as 'warblers' or 'wood warblers', despite not being at all closely related to the European warblers. Instead, parulids are members of the 'nine-primaried oscines', the passerine clade that also includes such birds as finches, buntings, sparrows, cardinals and tanagers. Within the nine-primaried oscines, parulids are closely related to the Icteridae, another American clade containing its fair share of representatives doomed to masquerade under stolen names (Barker et al. 2013).

Ovenbird Seiurus aurocapilla on its nest, photographed by M. C. Donald.

Though the nine-primaried oscines as a whole are fairly stable in their membership, recent years have seen a fair bit of shuffling back and forth between the clade's constituent families. As a result of this shuffling, the name 'Parulidae' has come to be associated with a core clade that excludes a number of more uncertainly placed taxa previously included in the family, such as the Central American wrenthrush Zeledonia coronata. A recent comprehensive study of the molecular phylogeny of the core parulids by Lovette et al. (2010) also resulted in a proposed shifting of many generic boundaries within the clade. According to Lovette et al., the basalmost member of the Parulidae is the ovenbird Seiurus aurocapilla, a migratory but monomorphic, relatively large parulid of North and Central America. Just to confuse matters, the name 'ovenbird' has also been used for an unrelated group of South American birds of the genus Furnarius. To be charitable, this is not a case of inappropriate name-saking, but refers to the construction by both groups of domed nests resembling an old earthernware oven. The next member of the parulids to split off was the worm-eating warbler Helmitheros vermivorus, a relatively long-billed species that migrates between the eastern United States and Central America.

Swainson's warbler Limnothlypis swainsonii, photographed by Greg Lavaty.

Next comes a clade of eight species classified in the genera Parkesia, Vermivora, Mniotilta, Limnothlypis and Protonotaria. The black-and-white warbler Mniotilta varia is noted for its distinctive feeding behaviour: it crawls along branches like a nuthatch or creeper, gleaning insects from the bark. The prothonotary warbler Protonotaria citrea is a bright yellow species that Kurt Vonnegut devoted some time to in Jailbird: "The song of a prothonotary warbler is notoriously monotonous, as I am the first to admit...Still—they are capable of expressing heartbreak—within strict limits, of course" (I personally feel the same about skylarks). The waterthrushes of the genus Parkesia are larger, terrestrially-feeding species.

Chestnut-sided warbler Setophaga pensylvanica, photographed by Cephas.
Other North American species are placed by Lovette et al. in the larger genera Geothlypis, Oreothlypis and Setophaga. The last genus contains the species previously included in Dendroica, but the recognition that the American redstart Setophaga ruticilla (again, no relation to the European redstart) is nested within Dendroica leads to the use of the older name. These genera include some of the most colorful parulids. The remaining genera Myiothlypis, Basileuterus, Cardellina and Myioborus form a mostly Neotropical clade. Myioborus species are also known as redstarts, presumably by comparison with the European birds as not one of them actually possesses a red tail. The name 'whitestart' has supposedly been proposed instead, but the only time that name appears to see use is when it is referred to by someone explaining why they are not using it...

REFERENCES

Barker, K. F., K. J. Burns, J. Klicka, S. M. Lanyon & I. J. Lovette. 2013. Going to extremes: contrasting rates of diversification in a recent radiation of New World passerine birds. Systematic Biology 62 (2): 298-320.

Lovette, I. J., J. L. Pérez-Emán, J. P. Sullivan, R. C. Banks, I. Fiorentino, S. Córdoba-Córdoba, M. Echeverry-Galvis, F. K. Barker, K. J. Burns, J. Klicka, S. M. Lanyon & E. Bermingham. 2010. A comprehensive multilocus phylogeny for the wood-warblers and a revised classification of the Parulidae (Aves). Molecular Phylogenetics and Evolution 57: 753-770.

Empire of the Sunfish

noreply@blogger.com (Christopher Taylor) — Wed, 27 Feb 2013 05:48:00 +0000

Do you remember when this particular nightmare was vomited forth from the jaws of pop culture hell?

Yes, this was the execrable Billy the Bass, just one more reason we can all be glad that the 90s aren't around any more. But what was it supposed to be?

Smallmouth bass Micropterus dolomieu, photographed by Eric Engbretson.

The bass and sunfishes of the family Centrarchidae are a group of more than thirty species of freshwater fish mostly native to North America east of the Rocky Mountains. A single species, the Sacramento perch Archoplites interruptus, is native to northern California. The family was more widely distributed in the past: the Oligocene–Miocene genera Plioparchus and Boreocentrarchus hail from Alaska, Oregon and the Dakotas (Near & Koppelman 2009). They will also be much more widely distributed in the future: species of the genera Lepomis and Micropterus have been introduced to numerous places around the world as sportfish. The centrarchids are all carnivorous, though the nature of their prey varies from zooplankton to insects to other fish.

White crappie Pomoxis annularis, photographed by D. Ross Robertson.

The molecular analysis of the Centrarchidae by Near et al. (2005) identified the mud sunfish Acantharchus pomotis as sister to all other centrarchids, contrary to its previous inclusion in the subfamily Centrarchinae with other centrarchids possessing more than three spines in the anal fin (Near & Koppelman 2009). Instead, the two genera whose species possess only three anal spines, Lepomis and Micropterus, form a clade that is sister to the remaining 'centrarchine' genera. These are the aforementioned Archoplites, the flier Centrarchus macropterus, the banded sunfishes Enneacanthus, the rock basses Ambloplites and the somewhat unfortunately named crappies of the genus Pomoxis. These are mostly deep-bodied feeders on small invertebrates, though the larger species may also take small fish. Archoplites is a more dedicated piscivore. This latter species is also notable for having less elaborate mating behaviour than other centrarchids: in contrast to the elaborate courtship rituals and nests of other centrarchids, Archoplites males do little more than use the tail fin to dig a small depression (Berra 2007). One can't resist wondering if Archoplites' lax behaviour is connected with its geographic isolation from other species.

Pumpkinseed Lepomis gibbosus, photographed by Cliff.

The genera Micropterus and Lepomis are each more diverse than the centrarchine genera. The black basses of the genus Micropterus are relatively long-bodied compared to other centrarchids, and are all piscivores. Lepomis, with twelve species, is the most diverse centrarchid genus both numerically and ecologically; as well as numerous insectivorous species, it contains the piscivorous warmouth Lepomis gulosus, the specialised planktivorous bluegill L. macrochirus, and two molluscivorous species, the redear sunfish L. microlophus and the pumpkinseed L.gibbosus. Phylogenetic relationships within Lepomis indicate a certain dynamism of ecology as well: a number of species pairs can be identified connecting large and small species, while the two molluscivores are not immediate relatives within the genus (Near et al. 2005).

REFERENCES

Berra, T. M. 2007. Freshwater Fish Distribution. University of Chicago Press.

Near, T. J., D. I. Bolnick & P. C. Wainwright. 2005. Fossil calibrations and molecular divergence time estimates in centrarchid fishes (Teleostei: Centrarchidae). Evolution 59 (8): 1768-1782.

Near, T. J., & J. B. Koppelman. 2009. Species diversity, phylogeny and phylogeography of the Centrarchidae. In: Cooke, S. J., & D. P. Philipp (eds) Centrarchid Fishes: Diversity, biology and conservation, pp. 1-38. Blackwell Publishing.

Chitonous Confusion

noreply@blogger.com (Christopher Taylor) — Tue, 26 Feb 2013 05:08:00 +0000

Lepidochitona cinerea, photographed by Rokus Groeneveld.

Chitons have been featured at this site once before, in a brief post on the family Ischnochitonidae. Today's post is focused on another chiton family, the Lepidochitonidae.

As noted in the earlier post, the field of chiton classification is a confusing place. The lepidochitonids were characterised by Kass & Van Belle (1985; under the name Lepidochitoninae, as a subfamily of the Ischnochitonidae) as chitons with slit-bearing valves, no extra-pigmentary eyes (i.e. no cuticular eyes outside the aesthetes, which are sensory canals in the valves), and a girdle that appears nude or has non-overlapping scales. Contrary to Kass & Van Belle's classification, however, the lepidochitonids do not appear to be immediately related to the ischnochitonids. Lepidochitonids have what are called abanal gills, in which new pairs of gills are only added during development in front of the first pair to develop (so the largest pair of gills is the furthest back), but ischnochitonids have adanal gills, in which new gill pairs are added both in front of and behind the original pair. The significance of this distinction has been corroborated by molecular analysis (Okusu et al. 2003). As for the composition of the Lepidochitonidae itself, Eernisse et al. (2007) referred two genera found in California, Cyanoplax and Nuttallina, to this family, but referred a third erstwhile lepidochitonine Tonicella to the family Mopaliidae, indicating the non-monophyly of the previously recognised grouping. In support of this, they cited in-progress molecular analyses. However, the detailed results of these analyses have yet to appear in print, so we are still unsure what the final face of the Lepidochitonidae will be.

Gould's baby chiton Cyanoplax dentiens, photographed by Gary McDonald.

The species of Cyanoplax are also of interest because of their varying reproductive habits. Four species in this genus studied by Eernisse (1998) are free spawners, releasing eggs into the water column where they hatch into free-swimming larvae that later settle and metamorphose elsewhere. Three other species, in contrast, are brooders, retaining their eggs to hatch at a later stage in development, bypassing the planktonic stage and reaching maturity close to their parent. Two of these brooding species, C. caverna and C. fernaldi, are also the only known examples of simultaneous hermaphrodites among chitons, seemingly able to fertilise their own eggs. As well as in larval development, brooding and free-spawning Cryptoplax species also differ in characters of the eggs, with the eggs of free-spawning species being more ornate than those of brooding species. This is of note as egg ornamentation has been suggested as a phylogenetically significant character in chitons; though this view has also been corroborated by molecular analysis (Okusu et al. 2003), the example of Cyanoplax recommends caution. The contrast between spawning vs brooding species in Cyanoplax also resembles situations found in other marine genera: starfish and annelid worms, for instance, each include examples of closely related yet developmentally distinct taxa.

REFERENCES

Eernisse, D. J. 1988. Reproductive patterns in six species of Lepidochitona (Mollusca: Polyplacophora) from the Pacific coast of North America. Biological Bulletin 174 (3): 287-302.

Eernisse, D. J., R. N. Clark & A. Draeger. 2007. Polyplacophora. In: J. T. Carlton (ed.) Light and Smith Manual: The Intertidal Invertebrates of Central California to Oregon, 4th ed., pp. 701-713. University of California Press: Berkeley.

Kaas, P., & R. A. Van Belle. 1985. Monograph of Living Chitons (Mollusca: Polyplacophora) vol. 2. Suborder Ischnochitonina. Ischnochitonidae: Schizoplacinae, Callochitoninae & Lepidochitoninae. E. J. Brill/Dr W. Backhuys.

Okusu, A., E. Schwabe, D. J. Eernisse & G. Giribet. 2003. Towards a phylogeny of chitons (Mollusca, Polyplacophora) based on combined analysis of five molecular loci. Organisms Diversity & Evolution 3: 281-302.

The Burlinius Head-hiders

noreply@blogger.com (Christopher Taylor) — Mon, 11 Feb 2013 05:00:00 +0000

Cryptocephalus (Burlinius) bilineatus, photographed by Josef Dvořák.

I may have to confess that, in direct opposition to the Deity, I am not overly fond of beetles. There are, quite simply, far too many of them, and even beetle families can be inordinately difficult to distinguish unless one is an expert (particularly the endless array of minute brown ones). Nevertheless, everything in beetles comes with an exception, and there are some groups that stand out: one of these is the leaf beetles of the Chrysomelidae. Chrysomelids are a highly diverse group, comparable to (though perhaps getting less press than) their close relatives the weevils and longicorns. They come in an enormous array of shapes and colours, and yet almost all (emphasis on almost) seem to carry an unmistakeable stamp saying, "I am a chrysomelid".

Cryptocephalus (Burlinius) pusillus, photographed by Amy.

The chrysomelid subgenus Burlinius of the genus Cryptocephalus includes over 120 species found across the Palaearctic region, with a single species known from the Simien Mountains of Ethiopia (Schöller 2002). The name Cryptocephalus means 'hidden head', and refers to how, when the beetle is viewed from above, the head is usually hidden underneath the pronotum. Species of Burlinius are relatively small with regular lines of punctures on the elytra, but are primarily distinguished from other Cryptocephalus species by the morphology of the male genitalia. The aedeagus (the intromittent organ) bears a dorsodistal appendage covering the dorsal opening, and two symmetrical ventral processes (Erber & Schöller 2006). The external appearance of many Burlinius species is known to be quite variable, and genital morphology is also the best way of distinguishing many species (Warchałowski 1999).

Figures from Warchałowski (1999) showing variation in elytral patterning between individuals of Cryptocephalus jocularius.

As you might have guessed from the vernacular name 'leaf beetles', chrysomelids are generally herbivorous. Host plant records for Burlinius species indicate that they are often polyphagous, feeding on a wide variety of hosts. Burlinius species have been recorded from legumes, composite-flowered plants, spurges, even pines (Erber & Schöller 2006). Cryptocephalus and related taxa belong to a subgroup of the chrysomelids called the Camptostomata, in which the females have an array of chitinous pads called the kotpresse in the rectum (Schöller 2008). The kotpresse is used to encase the eggs when they are laid in a covering made from faeces and other secretions; when the larvae hatches, it uses this covering for protection and adds to it itself as it grows.

Hazel pot beetle Cryptocephalus coryli larva in its protective case, photographed by Roger Key.

REFERENCES

Erber, D., & M. Schöller. 2006. Revision of the Cryptocephalus-species of the Canary Islands and Madeira (Insecta, Coleoptera, Chrysomelidae, Cryptocephalinae). Senckenbergiana Biologica 86 (1): 85-107.

Schöller, M. 2002. The first representative of Cryptocephalus subgen. Burlinius Lopatin from tropical Africa (Chrysomelidae: Cryptocephalinae). Genus 13 (1): 33-37.

Schöller, M. 2008. Comparative morphology of sclerites used by camptosomatan leaf beetles for formation of the extrachorion (Chrysomelidae: Cryptocephalinae, Lamprosomatinae). In: Jolivet, P., J. Santiago-Blay & M. Schmitt. Research on Chrysomelidae vol. 1, pp. 87-120. Brill: Leiden.

Warchałowski, A. 1999. Übersicht der westpaläarktischen Arten der Untergattung Burlinius Lopatin, 1965 (Coleoptera: Chrysomelidae: Cryptocephalus). Genus 10 (4): 529-627.

More on the New Zealand Opiliones

noreply@blogger.com (Christopher Taylor) — Tue, 05 Feb 2013 06:34:00 +0000

Male of Pantopsalis listeri, photographed by Simon Pollard, used with permission in Taylor (2013).

New paper published today! Hurrah! Except I've already had it pointed out to me that the species descriptions are missing the type depository, and one of the new species names has been mis-spelt in a couple of places. So I must shamefacedly prepare myself a correction...

The paper in question is titled 'Further notes on New Zealand Enantiobuninae (Opiliones, Neopilionidae), with the description of a new genus and two new species'. It's been published in ZooKeys, so it's freely available online at the link just given. As well as the two new species of harvestmen mentioned in the title, the paper also does something that I personally am even more pleased with: it manages to make two nomina dubia not dubia any more!

It started with my own private little eureka moment. A few months back, I was looking through some of the New Zealand harvestmen material that's been waiting for me to examine it. I pulled out one of the specimens and looked at it under the microscope. And as soon as I looked at it, I somehow had a thought pop into my mind: "That's Pantopsalis cheliferoides". Pantopsalis cheliferoides, I hasten to explain, is a species that was first described in 1882 by William Colenso, a missionary based in Ahuriri in Hawke's Bay. Colenso was a fascinating character, living with one hand firmly on the Bible and the other up a native girl's skirt (he was dismissed from the church in 1852 after fathering a child by his wife's maid, and not readmitted to its services until 1894). He produced the first book to be printed in New Zealand, and was the first to translate the Bible into Maori. He was also a keen natural historian, particularly interested in botany. His endeavours in zoology were perhaps a little less sure: when he collected the first specimens of P. cheliferoides, he doesn't seem to have been entirely sure if he was looking at a harvestman, a whip-spider, or a pseudoscorpion, so he kind of hedged his bets in giving it the name of Phalangium (Phrynus) cheliferoides. Unfortunately, P. cheliferoides then became something of a footnote in New Zealand arachnology. I had looked at the type specimen previously, but it wasn't enough for me to be sure of it's identity (and at the time, I was still a student and not confident enough to perform a genitalia dissection on a holotype). But it was enough that, when I came across more specimens of the species, I was able to recognise them for what they were. Hopefully, this will lift the animal that Colenso spent so much time trying to identify* out from its obscurity.

*In Colenso's own words: "I have only seen four specimens in the woods, throughout three years, although from my first seeing one in 1879 (which I failed to capture), I have sought most diligently for specimens. In the following year I accidentally, and most unexpectedly, saw another in the same forest, and though I tried long and arduously to secure it without smashing, I failed to do so; it spread out its long flexible legs so prodigiously, that in the end it escaped among the thick vegetation" (Colenso 1882).

Male Pantopsalis cheliferoides, from Taylor (2013).

The other nomen ex-dubium dealt with in the paper is arguably even more important, as it is the type species of the genus Pantopsalis. This species was first described as Phalangium listeri by A. White back in 1849, in about three lines of text that are completely inadequate to recognise the species in question (with no further locality data given than 'New Zealand'), and the type specimen(s) seem to have since been lost. The species was redescribed by the French arch-arachnologist Eugene Simon in 1879, who placed it in the new genus Pantopsalis. Recently, I was able to borrow Simon's P. listeri specimens from the Muséum national d’Histoire naturelle in Paris; as it turns out, they belong to the same species that I had dealt with in 2004 under the name of Pantopsalis luna. Because the original type was lost, I've designated one of the Paris specimens as the neotype for P. listeri. It isn't entirely certain that Simon was actually looking at the same species as White had been (indeed, as mentioned in the paper, there's some cause to believe he wasn't). But everyone since Simon has followed his lead on the identity of Pantopsalis, and naming one of his specimens as neotype has the advantage of confirming the status quo.

Male of Mangatangi parvum, from Taylor (2013).

The two new species in the paper are Forsteropsalis pureora (as it should have been throughout, dammit) and Mangatangi parvum. The latter species is particularly neat: it's very small compared to some of the other long-legged harvestmen in New Zealand, and certain features suggest that it may represent the sister taxon to the clade containing the genera Pantopsalis and Forsteropsalis. I'm still doing some work to try and test that.

REFERENCES

Colenso, W. 1882. On some newly-discovered New Zealand arachnids. Transactions and Proceedings of the New Zealand Institute 15: 165–73.

Trichadenotecnum: Six Spots and Spiny Terminalia

noreply@blogger.com (Christopher Taylor) — Mon, 04 Feb 2013 05:21:00 +0000

Trichadenotecnum sexpunctatum, photographed by Brian Valentine.

The animal in the photo above is a typical representative of Trichadenotecnum, a diverse genus of the barklice. About 200 species have been assigned to this genus from almost all the major biogeographic regions of the world except Australia (Yoshizawa et al. 2007); of the two species recorded from Australia and assigned to this genus, one (Ptycta enderleini) has recently been excluded from Trichadenotecnum, and the other (Trichadenotecnum circularoides) is probably a recent introduction from the Americas (Yoshizawa & Smithers 2006). Though long regarded as suspectly heterogenous, the genus has been extensively reviewed in recent years, particularly by Kazunori Yoshizawa of Hokkaido University and associates (Yoshizawa 2001, 2004; Yoshizawa et al. 2008). Members of Trichadenotecnum are characterised by a distinctive array of wing markings, visible in the above photo. Note, in particular, the series of six submarginal spots forming a U-shape towards the end of each wing (though, confusingly, these characteristic markings can become difficult to distinguish in species in which the wings are more heavily spotted overall). The genus is also distinguished by certain features of the male terminalia (or, in layman's terms, the bum) with a number of processes developed on the hypandrium, the posteriormost segment of the underside of the abdomen that covers the phallosome, the intromittent organ in Psocoptera. These processes vary in development between species, and often themselves bear arrays of small spines or teeth. A number of species of Trichadenotecnum also have the terminalia assymmetrically developed, with the left and right lobes of the hypandrium (for instance) differently sized and/or shaped, though the functional significance of this arrangement (if any) remains unknown.

Various views of the terminalia of Trichadenotecnum alexanderae, from Yoshizawa (2001). In life, the phallosome is contained within the underside of the terminalia.

The variability of the terminalia between species of Trichadenotecnum makes them a rich source of characters for use in taxonomy. The problem with this, of course, is that you need adult males, and that isn't always easy. Particularly in a group like Psocoptera, which seem to show a particular tendency for parthenogenesis. A number of Trichadenotecnum species are not, as yet, known to produce males, including the aforementioned T. circularoides, necessitating identifiers to fall back largely on wing markings. Trichadenotecnum circularoides has been recorded from Angola, east Asia, Australia, North America and Brazil; the distribution of closely related species suggests that the last locality represents its original homeland with human dispersal carrying it elsewhere (Yoshizawa et al. 2008). The New World species of Trichadenotecnum appear to fall within a small number of clades: one including T. circularoides is the sister group to other members of the genus, while the T. alexanderae species group is Holarctic in distribution. The majority of New World species, however, form a single lineage referred to as the 'bulky clade' by Yoshizawa et al. (2008). Members of the bulky clade have a movable median tongue on the hypandrium that bears a dorsal covering of denticles or spines. Yoshizawa et al. (2008) suggested that, as the bulky clade was nested amongst a number of Old World lineages, this group may represent a relatively recent invasion of the Americas, probably by way of the Bering Strait.

Nymphs of Trichadenotecnum possess glandular hairs to which frass and pieces of lichen become attached, providing them with camouflage. This individual was photographed by Charley Eiseman.
REFERENCES

Yoshizawa, K. 2001. A systematic revision of Japanese Trichadenotecnum Enderlein (Psocodea: ‘Psocoptera’: Psocidae: Ptyctini), with redefinition and subdivision of the genus. Invertebrate Taxonomy 15: 159-204.

Yoshizawa, K. 2004. Molecular phylogeny of major lineages of Trichadenotecnum and a review of diagnostic morphological characters (Psocoptera: Psocidae). Systematic Entomology 29: 383-394.

Yoshizawa, K., A. N. García Aldrete & E. L. Mockford. 2008. Systematics and biogeography of the New World species of Trichadenotecnum Enderlein (Insecta: Psocodea: ‘Psocoptera’: Psocidae). Zoological Journal of the Linnean Society 153: 651-723.

Yoshizawa, K., C. Lienhard & V. K. Thapa. 2007. Systematic study of the genus Trichadenotecnum in Nepal. Insecta Matsumurana, new series 63: 1-33.

Yoshizawa, K., & C. N. Smithers. 2006. Systematic position of Trichadenotecnum enderleini (Roesler) (Psocodea: “Psocoptera”: Psocidae). Records of the Australian Museum 58: 411-415.