AJCs Frogroom

Fatal chytrid fungus found in caecilians

noreply@blogger.com (AJ Cann) — Thu, 16 May 2013 11:26:00 +0000

This is really bad news. New research shows that chytrid fungus now infects all the major groups of amphibians and means that scientists now need to consider it as a potential threat to caecilians in the wild.

Because most species of caecilians live buried in the soil, they are rarely studied and very little is known about most of them. As a result, more than two thirds of caecilian species are 'Data Deficient' on the IUCN Red List because there is too little information to know if they are threatened or not. The last thing we need is massive species loss due to chytrid.

Keeping Sticky

noreply@blogger.com (AJ Cann) — Sun, 12 May 2013 06:56:00 +0000

How do frogs' toe pads stay sticky to stop them falling? Why don't they get clogged with dirt and stop sticking? Tree frogs' sticky toe pads remain clean after thousands of uses while sticky tape is useless after one. It turns out that the simple act of walking is sufficient to clean their toe pads.

First scientists tested how well contaminated and uncontaminated White's tree frogs clung to a glass plate as they rotated it from horizontal, through vertical to upside down. Because the frogs tended to want to jump off when they began to feel insecure, they gently encouraged the frogs to hold tight by shielding them with their hands and caught them when the plate became too steep and the frog's hold failed. Monitoring the plate's angle, the team found that the frogs with uncontaminated feet only began to slip as the plate tipped over (106 deg) and finally lost their grip at 142 deg. However, when they dusted the frog's feet with microscopic glass beads, the animals began slipping soon after the glass plate began to tilt. They had lost adhesion, so how could they recover?

Holding a tree frog on a computer-controlled stage and carefully applying a single layer of glass beads to one of its toe pads, they carefully pressed the contaminated toe onto a glass coverslip and then pulled it free. Measuring the adhesion force as they pulled the frog away, they found that it had fallen to zero: the frog was completely incapable of clinging on to the smooth surface with its contaminated feet. Simply dabbing the toe onto a surface was not sufficient to clean it. However, when they simulated real tree frog footsteps, by gently dragging the toe pad sideways after contact with the coverslip, the situation was completely different. Over the course of eight simulated footsteps the toe pad gradually recovered adhesion, slowly at first, returning to normal by the final contact.

So the keys to the tree frog's self-cleaning success are the sliding motion – which shears particles away from the toe pad and increases the contact area with the surface – and the sticky mucous secretions – which help flush away contaminants.

Self-cleaning in tree frog toe pads; a mechanism for recovering from contamination without the need for grooming. (2012) The Journal of experimental biology, 215(22), 3965-3972
Tree frogs use adhesive toe pads for climbing on a variety of surfaces. They rely on wet adhesion, which is aided by the secretion of mucus. In nature, the pads will undoubtedly get contaminated regularly through usage, but appear to maintain their stickiness over time. Here, we show in two experiments that the toe pads of White's tree frogs (Litoria caerulea) quickly recover from contamination through a self-cleaning mechanism. We compared adhesive forces prior to and after contamination of (1) the whole animal on a rotatable platform and (2) individual toe pads in restrained frogs mimicking individual steps using a motorised stage. In both cases, the adhesive forces recovered after a few steps but this took significantly longer in single toe pad experiments from restrained frogs, showing that use of the pads increases recovery. We propose that both shear movements and a 'flushing' effect of the secreted mucus play an important role in shedding particles/contaminants.

Complex history of chytrid

noreply@blogger.com (AJ Cann) — Tue, 07 May 2013 13:59:00 +0000

Scientists have just published a complicated scientific paper on the devastating amphibian pathogen Batrachochytrium dendrobatidis (Bd - chytrid). The full version is below, but here's the summary:

They sequenced the genome from 29 isolates of Bd from around the world and found a lot more genetic variation than previously reported. So what? This means that the worldwide chytrid "pandemic" is more complicated than previously thought, and one size does not fit all outbreaks.

The major disease-linked amphibian population declines predate the late 20th century emergence of this pathogen in amphibians. Is Bd was simply an unrecognized member of amphibian communities that suddenly turned lethal and is it a new pathogen? This new data Bd shows that Bd has been in some amphibian populations for a very long time. In others it is a recent introduction. Proteases are confirmed as important in Bd infection of amphibian skin and in causing the disease.

The history of the chytrid pandemic is complex and a long way away from the idea that a "new" disease suddenly wiped out many of the world's amphibians.

Complex history of the amphibian-killing chytrid fungus revealed with genome resequencing data. PNAS USA 06 May 2013, doi: 10.1073/pnas.1300130110
Understanding the evolutionary history of microbial pathogens is critical for mitigating the impacts of emerging infectious diseases on economically and ecologically important host species. We used a genome resequencing approach to resolve the evolutionary history of an important microbial pathogen, the chytrid Batrachochytrium dendrobatidis (Bd), which has been implicated in amphibian declines worldwide. We sequenced the genomes of 29 isolates of Bd from around the world, with an emphasis on North, Central, and South America because of the devastating effect that Bd has had on amphibian populations in the New World. We found a substantial amount of evolutionary complexity in Bd with deep phylogenetic diversity that predates observed global amphibian declines. By investigating the entire genome, we found that even the most recently evolved Bd clade (termed the global panzootic lineage) contained more genetic variation than previously reported. We also found dramatic differences among isolates and among genomic regions in chromosomal copy number and patterns of heterozygosity, suggesting complex and heterogeneous genome dynamics. Finally, we report evidence for selection acting on the Bd genome, supporting the hypothesis that protease genes are important in evolutionary transitions in this group. Bd is considered an emerging pathogen because of its recent effects on amphibians, but our data indicate that it has a complex evolutionary history that predates recent disease outbreaks. Therefore, it is important to consider the contemporary effects of Bd in a broader evolutionary context and identify specific mechanisms that may have led to shifts in virulence in this system.

Dendrobates azureus

noreply@blogger.com (AJ Cann) — Sun, 05 May 2013 12:53:00 +0000

Frogroom Weekend - 14th April

noreply@blogger.com (AJ Cann) — Sun, 14 Apr 2013 16:33:00 +0000

Magnificent brood frog (Pseudophryne covacevichae). Endangered on the IUCN Red List.

The Big Newt Count - Monday 22 April, Fens Pool, Dudley. Join ecologists for an interesting evening of newt counting on the Fens Pools near Dudley.

Saviors or villains: controversy erupts as New Zealand plans to drop poison over Critically Endangered frog habitat.

Who’s afraid of the big fat frog? A man with a phobia of frogs has won $1.6million in damages after run-off water from a neighbouring property turned his home into an amphibian-friendly wetland.

Nasikabatrachus sahyadrensis - the Purple Frog, or the Pignose Frog.

Not all frogs come from tadpoles. All tadpoles grow into frogs, but not all frogs start out as tadpoles, reveals a new study on 720 species of frogs.

The Panamanian golden frog (Atelopus zeteki) is a small species of “true toad” native to the mountainous rainforests of Panama — although now thought to be extinct in the wild, and currently surviving only in captivity.

Dead frogs, drowning mice, sick dogs – it’s not a jolly spring for some creatures. Frogs … the pit canaries of the planet. If they go, we’ve probably all had it.

To Understand the Springtail, you must Become the Springtail

noreply@blogger.com (AJ Cann) — Tue, 09 Apr 2013 15:32:00 +0000

In 2005 Steve Hopkin, God of All Things Springtail, published this great review about my favourite springtail species (whaddya mean, you don't have a favourite springtail species?), Folsomia candida.

Folsomia candida (Collembola): A “Standard” Soil Arthropod. (2005) Annual Review of Entomology 50: 201-222

Among the great snippets of information it contains are the following gems:

Folsomia candida is parthenogenetic and is easy to maintain in the laboratory on a diet of granulated dry yeast.

F. candida has been used as a “standard” test organism for more than 40 years for estimating the effects of pesticides and environmental pollutants on soil arthropods.

F. candida is considered a tramp species (54). Because it has been carried all over the world in plant pots and soil its original biogeographical locations are difficult to ascertain.

Populations of F. candida consist exclusively of parthenogenetic females.

At 20°C they take between 21 and 24 days to reach the sixth, or adult, instar when they are sexually mature. At lower temperatures, the time span for each developmental stage is extended. For example, the average lifespan of a female at 15°C is 240 days, whereas at 24°C it is only 111 days.

About 30 to 50 eggs are laid in each batch, which take 7 to 10 days to hatch.

The optimal temperature for hatching success is 21°C. Eggs maintained above 28°C fail to hatch.

At 15, 21, and 27°C, the average number of eggs laid by a female during her lifetime is around 1100, 900, and only 100, respectively.

Eggs are often laid in communal heaps, in which females add to previously laid batches.

An adult female may go through 45 molts in her lifetime with short reproductive instars (duration 1.5 days) alternating with longer nonreproductive instars (duration 8.5 days).

All life stages of F. candida are well adapted to dry soil conditions. The species possesses physiological adaptations to desiccation and absorbs water vapor and remains active below 98.9% relative humidity (the permanent wilting point of plants).

Oxygen uptake is via the cuticle - F. candida does not possess tracheae.

The gut passage time of F. candida at 20°C is approximately 35 min.

F. candida feeds on fungal hyphae and exhibits strong preferences for particular species

The fungus on which F. candida feeds influences its growth and fecundity. Laboratory experiments with F. candida held in different microcosms, with only one species of fungus available in each, have shown that some taxa of fungi are more nutritious than others.

F. candida shows a mild preference to settle on soils of pH 5.6, at which females achieve their highest level of reproduction compared with more acidic or alkaline conditions.

Bumper Box of Plants

noreply@blogger.com (AJ Cann) — Tue, 09 Apr 2013 07:34:00 +0000

(Sorry, UK Only)

Starting a new viv? You need: Bumper Box of Plants (box not included)
Large well-rooted cuttings of:

Pellionia daveauna
Scindapsus aureus (Pothos)
Scindapsus pictus
Selaginella plana
Syngonium rayii
Tradescantia zebrina

Suited to a damp amphibian vivarium. Will thrive in moderate lighting. If you'd like more info, Google the names for pictures, and in some cases searching for the names on YouTube will work.
£15 (+ £5 P&P if needed, or collect from Leicester).

Daddy takes baby for a walk

noreply@blogger.com (AJ Cann) — Sat, 02 Jun 2012 16:56:00 +0000

New species of tiny frog is world’s smallest vertebrate

noreply@blogger.com (AJ Cann) — Thu, 12 Jan 2012 08:17:00 +0000

Researchers have found two new frog species in New Guinea, one of which is the new smallest known vertebrate on Earth. The new smallest vertebrate species is called Paedophryne amauensis, named after Amau Village in Papua New Guinea, where it was found. The adult body size for these frogs ranges from just 7.0 to 8.0 millimeters. The previous smallest vertebrate was a fish, called Paedocypris progenetica, with an adult size of 7.9 to 10.3 millimeters.

Rittmeyer EN, Allison A, Gruundler MC, Thompson DK, Austin CC (2012) Ecological Guild Evolution and the Discovery of the World’s Smallest Vertebrate. PLoS ONE 7(1): e29797. doi:10.1371/journal.pone.0029797
Living vertebrates vary drastically in body size, yet few taxa reach the extremely minute size of some frogs and teleost fish. Here we describe two new species of diminutive terrestrial frogs from the megadiverse hotspot island of New Guinea, one of which represents the smallest known vertebrate species, attaining an average body size of only 7.7 mm. Both new species are members of the recently described genus Paedophryne, the four species of which are all among the ten smallest known frog species, making Paedophryne the most diminutive genus of anurans. This discovery highlights intriguing ecological similarities among the numerous independent origins of diminutive anurans, suggesting that minute frogs are not mere oddities, but represent a previously unrecognized ecological guild.

Frogs croak about their pads

noreply@blogger.com (AJ Cann) — Thu, 22 Dec 2011 12:09:00 +0000

During female mate choice, both the male's phenotype and resources (e.g. his nest) contribute to the chooser's fitness. Animals other than humans are not known to advertise resource characteristics to potential mates through vocal communication; although in some species of anurans and birds, females do evaluate male qualities through vocal communication. Here, we demonstrate that calls of the male Emei music frog (Babina dauchina), vocalizing from male-built nests, reflect nest structure information that can be recognized by females. Inside-nest calls consisted of notes with energy concentrated at lower frequency ranges and longer note durations when compared with outside-nest calls. Centre frequencies and note durations of the inside calls positively correlate with the area of the burrow entrance and the depth of the burrow, respectively. When given a choice between outside and inside calls played back alternately, more than 70 per cent of the females (33/47) chose inside calls. These results demonstrate that males of this species faithfully advertise whether or not they possess a nest to potential mates by vocal communication, which probably facilitates optimal mate selection by females. These results revealed a novel function of advertisement calls, which is consistent with the wide variation in both call complexity and social behaviour within amphibians.

Real estate ads in Emei music frog vocalizations: female preference for calls emanating from burrows. Biology Letters, 7 December 2011

Ecopathology of Ranaviruses Infecting Amphibians

noreply@blogger.com (AJ Cann) — Fri, 09 Dec 2011 11:37:00 +0000

Ranaviruses are capable of infecting amphibians from at least 14 families and over 70 individual species. Ranaviruses infect multiple cell types, often culminating in organ necrosis and massive hemorrhaging. Subclinical infections have been documented, although their role in ranavirus persistence and emergence remains unclear. Water is an effective transmission medium for ranaviruses, and survival outside the host may be for significant duration. In aquatic communities, amphibians, reptiles and fish may serve as reservoirs. Controlled studies have shown that susceptibility to ranavirus infection and disease varies among amphibian species and developmental stages, and likely is impacted by host-pathogen coevolution, as well as, exogenous environmental factors. Field studies have demonstrated that the likelihood of epizootics is increased in areas of cattle grazing, where aquatic vegetation is sparse and water quality is poor. Translocation of infected amphibians through commercial trade (e.g. food, fish bait, pet industry) contributes to the spread of ranaviruses. Such introductions may be of particular concern, as several studies report that ranaviruses isolated from ranaculture, aquaculture, and bait facilities have greater virulence (i.e., ability to cause disease) than wild-type isolates. Future investigations should focus on the genetic basis for pathogen virulence and host susceptibility, ecological and anthropogenic mechanisms contributing to emergence, and vaccine development for use in captive populations and species reintroduction programs.

Ecopathology of Ranaviruses Infecting Amphibians. (2011) Viruses 2011, 3(11), 2351-2373

Pathogenicity in Chytrid Fungi

noreply@blogger.com (AJ Cann) — Wed, 09 Nov 2011 16:07:00 +0000

The chytrid fungus Batrachochytrium dendrobatidis (Bd) is an emerging pathogen that has been implicated in decimating amphibian populations around the world. Bd is the only member of an ancient group of fungi (called the Chytridiomycota) that is known to attack vertebrates. The question of how an amphibian-killing fungus evolved from non-pathogenic ancestors is vital to protecting the world's remaining amphibians from Bd.

Researchers sequenced the genome of Bd's closest known relative - a non-pathogenic chytrid named Homolaphlyctis polyrhiza (Hp). They compared the genomes of Bd, Hp and 18 additional fungi to identify what makes Bd unique, and identified a large number of Bd-specific genes, a gene set that contains a number of possible pathogenicity factors. In particular, this paper describes a large number of protease genes in the Bd genome and show that these genes were duplicated after the divergence of Bd and Hp from their common ancestor. Studying Bd's pathogenesis in an evolutionary context provides new evidence for the role of protease genes in Bd's ability to kill amphibians.

Genomic Transition to Pathogenicity in Chytrid Fungi. (2011) PLoS Pathog 7(11): e1002338. doi:10.1371/journal.ppat.1002338
Understanding the molecular mechanisms of pathogen emergence is central to mitigating the impacts of novel infectious disease agents. The chytrid fungus Batrachochytrium dendrobatidis (Bd) is an emerging pathogen of amphibians that has been implicated in amphibian declines worldwide. Bd is the only member of its clade known to attack vertebrates. However, little is known about the molecular determinants of - or evolutionary transition to - pathogenicity in Bd. Here we sequence the genome of Bd's closest known relative - a non-pathogenic chytrid Homolaphlyctis polyrhiza (Hp). We first describe the genome of Hp, which is comparable to other chytrid genomes in size and number of predicted proteins. We then compare the genomes of Hp, Bd, and 19 additional fungal genomes to identify unique or recent evolutionary elements in the Bd genome. We identified 1,974 Bd-specific genes, a gene set that is enriched for protease, lipase, and microbial effector Gene Ontology terms. We describe significant lineage-specific expansions in three Bd protease families (metallo-, serine-type, and aspartyl proteases). We show that these protease gene family expansions occurred after the divergence of Bd and Hp from their common ancestor and thus are localized to the Bd branch. Finally, we demonstrate that the timing of the protease gene family expansions predates the emergence of Bd as a globally important amphibian pathogen.

On the origin of chytridiomycosis

noreply@blogger.com (AJ Cann) — Tue, 08 Nov 2011 16:12:00 +0000

One of the more puzzling aspects of the emergence of amphibian chytridiomycosis has been that, whereas epizootics have been widely observed, many susceptible amphibian communities apparently coexist alongside Bd with no evidence of disease. This new paper shows that the Bd genotype is also an important epidemiological determinant.

In addition, a commentary in New Scientist suggests that the global amphibian trade not only spread the lethal chytrid fungus, but may have created the disease in the first place: Frog-killer disease was born in trade.

Multiple emergences of genetically diverse amphibian-infecting chytrids include a globalized hypervirulent recombinant lineage. PNAS USA November 7, 2011
Batrachochytrium dendrobatidis (Bd) is a globally ubiquitous fungal infection that has emerged to become a primary driver of amphibian biodiversity loss. Despite widespread effort to understand the emergence of this panzootic, the origins of the infection, its patterns of global spread, and principle mode of evolution remain largely unknown. Using comparative population genomics, we discovered three deeply diverged lineages of Bd associated with amphibians. Two of these lineages were found in multiple continents and are associated with known introductions by the amphibian trade. We found that isolates belonging to one clade, the global panzootic lineage (BdGPL) have emerged across at least five continents during the 20th century and are associated with the onset of epizootics in North America, Central America, the Caribbean, Australia, and Europe. The two newly identified divergent lineages, Cape lineage (BdCAPE) and Swiss lineage (BdCH), were found to differ in morphological traits when compared against one another and BdGPL, and we show that BdGPL is hypervirulent. BdGPL uniquely bears the hallmarks of genomic recombination, manifested as extensive intergenomic phylogenetic conflict and patchily distributed heterozygosity. We postulate that contact between previously genetically isolated allopatric populations of Bd may have allowed recombination to occur, resulting in the generation, spread, and invasion of the hypervirulent BdGPL leading to contemporary disease-driven losses in amphibian biodiversity.

Remember, remember the amphibians on the 5th of November!

noreply@blogger.com (AJ Cann) — Fri, 04 Nov 2011 16:50:00 +0000

The Royal Horticultural Society, The Wildlife Trusts and Amphibian and Reptile Conservation are asking organisers of bonfire night celebrations to look out for amphibians before they light their fires.
"People tend to check for hedgehogs in the wood they have gathered for their fire," says Andrew Halstead, Principal RHS Entomologist. "But it is equally likely that toads, frogs and newts will have found shelter in these piles and might be missed. Toads and frogs play an important role as predators in the garden and should be encouraged."

via ARC

Antiviral Immunity in Amphibians

noreply@blogger.com (AJ Cann) — Thu, 03 Nov 2011 16:46:00 +0000

Although a variety of virus species can infect amphibians, diseases caused by ranaviruses (RVs) have become prominent, and are a major concern for biodiversity, agriculture and international trade. The relatively recent and rapid increase in prevalence of RV infections, the wide range of host species infected by RVs, the variability in host resistance among population of the same species and among different developmental stages, all suggest an important involvement of the amphibian immune system. Nevertheless, the roles of the immune system in the etiology of viral diseases in amphibians are still poorly investigated. We review here the current knowledge of antiviral immunity in amphibians, focusing on model species such as the frog Xenopus and the salamander (Ambystoma tigrinum), and on recent progress in generating tools to better understand how host immune defenses control RV infections, pathogenicity, and transmission.

Antiviral Immunity in Amphibians. Viruses. 2011; 3(11):2065-2086

Anubias barteri var. nana

noreply@blogger.com (AJ Cann) — Fri, 02 Sep 2011 15:22:00 +0000

I've been growing this species for over 15 years. This is the first time it has ever flowered (in the Mannophryne trinitatis palludarium).

Mannophryne trinitatis

noreply@blogger.com (AJ Cann) — Sat, 27 Aug 2011 17:22:00 +0000

Just emerged :-)

Eric Young Orchid Foundation

noreply@blogger.com (AJ Cann) — Sat, 06 Aug 2011 10:31:00 +0000

On a recent visit to Jersey, the Eric Young Orchid Foundation was high on my list of places to visit:

The site is primarily a commercial nursery (with RHS Chelsea Flower show gold medals galore), but oddly, no plant sales (perhaps that's a good thing ;-)
If you're ever on Jersey, a must see.

Jersey Zoo

noreply@blogger.com (AJ Cann) — Sun, 31 Jul 2011 16:27:00 +0000

I grew up reading Gerald Durrell's books, so on a recent visit to Jersey, the Zoo was high on my list of places to visit. And that turned out to be a very good decision. I'll just describe the amphibian collection here - quite small but perfectly displayed - the best public vivaria I have ever seen:

In addition to the species on display, a number of species are also being bred off-exhibit - a newly set up Amano-style aquarium in the entrance building contained a very young Typhlonectes natans, still with gill abscission scars. I hope they don't leave it there - it won't hang around in that open-top tank too long.

Do Frogs Get Their Kicks on Route 66?

noreply@blogger.com (AJ Cann) — Fri, 22 Jul 2011 05:37:00 +0000

The chytrid fungus Batrachochytrium dendrobatidis (Bd) has been devastating amphibians globally. Two general scenarios have been proposed for the nature and spread of this pathogen: Bd is an epidemic, spreading as a wave and wiping out individuals, populations, and species in its path; and Bd is endemic, widespread throughout many geographic regions on every continent except Antarctica. To explore these hypotheses, we conducted a transcontinental transect of United States Department of Defense (DoD) installations along U.S. Highway 66 from California to central Illinois, and continuing eastward to the Atlantic Seaboard along U.S. Interstate 64 (in sum from Marine Corps Base Camp Pendleton in California to Naval Air Station Oceana in Virginia). We addressed the following questions:

Does Bd occur in amphibian populations on protected DoD environments?
Is there a temporal pattern to the presence of Bd?
Is there a spatial pattern to the presence of Bd? and
In these limited human-traffic areas, is Bd acting as an epidemic (i.e. with evidence of recent introduction and/or die-offs due to chytridiomycosis), or as an endemic (present without clinical signs of disease)?

Bd was detected on 13 of the 15 bases sampled. Samples from 30 amphibian species were collected (10% of known United States' species); half (15) tested Bd positive. There was a strong temporal (seasonal) component; in total, 78.5% of all positive samples came in the first (spring/early-summer) sampling period. There was also a strong spatial component - the eleven temperate DoD installations had higher prevalences of Bd infection (20.8%) than the four arid (<60 mm annual precipitation) bases (8.5%). These data support the conclusion that Bd is now widespread, and promote the idea that Bd can today be considered endemic across much of North America, extending from coast-to-coast, with the exception of remote pockets of naïve populations.

Do Frogs Get Their Kicks on Route 66? Continental U.S. Transect Reveals Spatial and Temporal Patterns of Batrachochytrium dendrobatidis Infection. PLoS ONE 6(7): e22211

Call for help - Phyllobates terribilis

noreply@blogger.com (AJ Cann) — Thu, 09 Jun 2011 02:02:00 +0000

A reader asks: Do you know where the Quebrada Guangui or La Brea area of Colombiais? Phyllobates terribilis is known to exist there and I can't seem to find any map showing their location. Any help is appreciated.

Phyllobates terribilis is a lowland species from the Pacific coast of Colombia. This area has high rainfall (5 m or more), altitude between 100–200 m, temperature of at least 26°C, and relative humidity of 80–90%.

The "Mint" morph is found at Quebrada Guanguia, Quinchia, Risaralda, Colombia:

View Larger Map

And the "Yellow" morph at La Brea, Tumaco, Nariño Department, Colombia, close to the border between Columbia and Ecuador:

View Larger Map

Catch-22

noreply@blogger.com (AJ Cann) — Tue, 31 May 2011 18:09:00 +0000

"Amphibian populations around the world are facing twin threats: habitat loss and the fungal disease chytridiomycosis. Unfortunately, solving one problem may exacerbate the other - it seems pristine habitats hold the greatest risk of the disease..."

Read more: No safe haven for amphibians: Nature News

Sobering thoughts

noreply@blogger.com (AJ Cann) — Fri, 27 May 2011 15:24:00 +0000

"The role of Bd in ongoing devastating species collapses and extinction events may provide insights into historical events that profoundly altered the trajectory of the animal kingdom on Earth. Arturo Casadevall proposed a provocative model that fungi were involved in the extinction of the dinosaurs. We know that 65 million years ago, a meteor struck the Yucatan Peninsula, and the Earth was enveloped by a resulting dust cloud that killed many of the animals and plants on the planet. As a consequence, a fungal bloom ensued that degraded the ubiquitous dead and decaying plant material. We know this because adjacent to the iridium peak in the fossil record we can see a layer of fungal spores at the KT boundary. This fungal bloom is thought to have given rise to a high density of aerosolized fungal spores, and conjectured to have infected the dinosaurs that were thought to be either poikilothermic (cold-blooded) or only partially homeothermic, and therefore unable to restrict the growth of fungi afforded by the higher core body temperature present in mammals. As a consequence, the mammals flourished and emerged to become the dominant life form on the planet, replacing the dinosaurs and other reptiles. That Bd is causing contemporary extinction events lends support to the notion that infectious diseases caused by fungi may have dramatically shaped the evolutionary trajectory of life on our planet, including that of our own species."

Microbial pathogens in the fungal kingdom. (2011) Fungal Biology Reviews 25(1): 48-60

Phyllobates terribilis vivarium

noreply@blogger.com (AJ Cann) — Sat, 14 May 2011 11:56:00 +0000

Quick wobbly video of the new Phyllobates terribilis vivarium:

Hi, what are you doing for lunch?

noreply@blogger.com (AJ Cann) — Sun, 08 May 2011 09:51:00 +0000

New arrival in the frogroom :-)