AJCs Frogroom

New species of tiny frog is world’s smallest vertebrate

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

Just emerged :-)

Eric Young Orchid Foundation

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

New arrival in the frogroom :-)

It's aphid time

noreply@blogger.com (AJC) — Sun, 01 May 2011 08:49:00 +0000

Dartfrogs love aphids, as this video by frankdrewes shows, and provided they are collected from a clean, chemical-free area, they are a great way of diversifying your frogs diet:

I've often had frogs breed after starting this seasonal treat, so get out there now, and start collecting!

The Orange Juice Experiment

noreply@blogger.com (AJC) — Fri, 29 Apr 2011 11:45:00 +0000

In a recent thread on Dendroworld, there was a claim that replacing orange juice with water reduced the smell of Drosophila cultures. I've been testing this and now I have the results.

I can see no difference in the smell of cultures with or without OJ. That is, some cultures smell worse than others, but this doesn't seem to be controlled by juice/water. How wet the culture is seems to be a more important factor. What I do see is that cultures with water rather than OJ produce noticeably fewer flies, so I'm sticking with the original OJ recipe.

A sad day

noreply@blogger.com (AJC) — Sun, 17 Apr 2011 15:02:00 +0000

The patriarch, my oldest dartfrog (shown here with her lifelong partner), has passed away. Peacefully, seemingly of old age. I don't know how old these frogs were as they are the only wild caught dartfrogs I have ever owned, although I received them in 2004 from another keeper, not directly from the wild. If you've ever received any Patricia from me, they were descendants of this frog.

She is succeeded by one of her many granddaughters, but will still be missed.

Hot in here?

noreply@blogger.com (AJC) — Sat, 16 Apr 2011 13:42:00 +0000

The Photobooth app on my shiny new iPad2 (yeah, get over it ;-) has a "Thermal Camera" setting, so I snapped this. I'm not entirely convinced how accurate this is, but it does point to something very interesting - the existence of thermal microclimates within a vivarium.

When your frogs wander around, they're doing more than entertaining themselves, they're regulating their body temperature by seeking out the correct thermal zone. This is one reason why frogs will always be happier in a big vivarium than a small one (in addition to all the other benefits).

As the weather gets warmer - be careful, don't let them overheat!

My old friend

noreply@blogger.com (AJC) — Fri, 08 Apr 2011 15:36:00 +0000

Just out of the water

noreply@blogger.com (AJC) — Wed, 06 Apr 2011 15:33:00 +0000

Mannophryne triniatis

Another trip down memory lane

noreply@blogger.com (AJC) — Sat, 02 Apr 2011 10:20:00 +0000

I've been fiddling around with old videos recently. I don't own any of these animals any more, but it's good to see old friends:

(Typhlonectes natans, firebellied toads)

Treadmill tests for poison frogs

noreply@blogger.com (AJC) — Wed, 30 Mar 2011 16:06:00 +0000

"The most toxic, brightly colored members of the poison frog family may also be the best athletes, says a new study.
As it turns out, the most boldly-colored and bad-tasting species are also the most physically fit, the authors report this week in the journal Proceedings of the National Academy of Sciences.
In forests in Colombia, Ecuador, Venezuela, and Panamá, Santos subjected nearly 500 poison frogs - representing more than 50 species - to a frog fitness test. He measured their oxygen uptake during exercise using a rotating plastic tube, turning the tube like a hamster wheel to make the frogs walk.
Santos estimated the frogs' metabolic rates while at rest, and again after four minutes of exercise. The result? The most dazzling and deadly species had higher aerobic capacity than their drab, nontoxic cousins.
"They're better able to extract oxygen from each breath and transport it to their muscles, just like well-trained athletes," Santos said."

via Treadmill tests for poison frogs show toxic species are more physically fit

J.C. Santos, D.C. Cannatella. Phenotypic integration emerges from aposematism and scale in poison frogs. Proceedings of the National Academy of Sciences, 2011; DOI: 10.1073/pnas.1010952108