Robot frog

Researchers at the University of Tokyo have developed a robot which can jump like a frog. The robot frog is 120cm tall and is pneumatically powered. Makes a change! Here's the video:

How to kill frogs

When you throw something away, it never really goes away. Out of sight, out of mind. Ah, you say, but I care about the environment, so I use biodegradable detergent, plastic bags, etc. But those still don't go away. They rot, and eventually the bacteria that eat them die and release the matter in the form of nutrients such as nitrates and phosphates. And those have to go somewhere. Eventually, they enter water courses in a process called eutrophication.

Eutrophication is bad. It makes nasty, stinky algae grow which kill aquatic plants. But it's worse than that. Eutrophication kills amphibians. Not always directly, but in subtle and disturbing ways.

In a scientific paper just published, scientists showed that eutrophication of aquatic ecosystems by nitrogen and phosphorus enrichment is a pervasive form of environmental change which causes disease in amphibians both through direct and through indirect pathways. Working with a disease-causing organism called Ribeiroia ondatrae, a trematode parasite which causes high frequencies of malformations (10 –90%) in amphibian populations, including missing, extra and malformed limbs, they showed that eutrophication enhances Ribeiroia transmission and made the link between organic pollution and amphibian population declines.

So what does it all mean? Well it means that amphibians and amphibian larvae in polluted environments (including vivaria and aquaria) are more susceptible to disease than those in clean environments. It also means that if you're serious about helping amphibians survive, you need to:

Reduce, Reuse, Recycle

in that order.

The widespread emergence of human and wildlife diseases has challenged ecologists to understand how large-scale agents of environmental change affect host–pathogen interactions. Accelerated eutrophication of aquatic ecosystems owing to nitrogen and phosphorus enrichment is a pervasive form of environmental change that has been implicated in the emergence of diseases through direct and indirect pathways. We provide experimental evidence linking eutrophication and disease in a multihost parasite system. The trematode parasite Ribeiroia ondatrae sequentially infects birds, snails, and amphibian larvae, frequently causing severe limb deformities and mortality. Eutrophication has been implicated in the emergence of this parasite, but definitive evidence, as well as a mechanistic understanding, have been lacking until now. We show that the effects of eutrophication cascade through the parasite life cycle to promote algal production, the density of snail hosts, and, ultimately, the intensity of infection in amphibians. Infection also negatively affected the survival of developing amphibians. Mechanistically, eutrophication promoted amphibian disease through two distinctive pathways: by increasing the density of infected snail hosts and by enhancing per-snail production of infectious parasites. Given forecasted increases in global eutrophication, amphibian extinctions, and similarities between Ribeiroia and important human and wildlife pathogens, our results have broad epidemiological and ecological significance.
Aquatic eutrophication promotes pathogenic infection in amphibians
Proc. Natl. Acad. Sci. USA, September 24, 2007

Another great frog blog

Frog Matters by Jeff Davis is an great blog about amphibians, focusing mostly on conservation. Go and check it out (you know you haven't got anything better to do!)

Video of the Day: Dendrobates leucomelas mating

A nice video showing classic Dendrobates mating behavior in D. leucomelas. Although you don't see the male calling in this sequence, that is normally the start of the process. The female strokes the male with her front feet and the male leads her to his preferred spawning site, in this case a 35mm film cannister, where the eggs are laid and fertilized:

It's a tight squeeze in there - I don't think my leucomelas could both fit into a film cannister, so they have a cocohut with a nice leaf to spawn on.

Frog of the Day: Hyla arborea

Frog of the day is the European tree frog (Hyla arborea):

Very popular with amphibian keepers before more exotic species such as dartfrogs became available in the 1980s, Hyla arborea is a tough and easy to maintain species which suffers from two main drawbacks - it is mostly nocturnal and pretty inactive during the day, and you need to be prepared for noise levels which will have neighbours complaining several streets away!

Argh - fly crisis

I breed two species of flightless fruit flies (Drosophila) as the staple diet for my dartfrogs (and for newly metamorphosed caudates).

Drosophila melanogaster is good for smaller species and newly metamorphosed frogs. I also breed a larger species, which for many years I believed was Drosophila hydei, but which I have been informed is more likely to be Drosophila funebris. (How do you tell the difference between these species?)

Apart from size, the main reason I maintain the two species is that they have slightly different culture preferences. This means that there is usually one type doing well even if the other is struggling. I regularly have a problem producing enough flies from my frogs, usually in the Spring and in the Autumn. Even though I culture flies in a closed cabinet, it seems that they can sense the change in the seasons. I have maintained both of these strains for some years (to be honest, I forget exactly how long). About a month ago, I started to have difficulty with the large species. Some cultures failed, and others seemed to be very slow to start producing. The odd failed culture happens occasionally, for reasons unknown, so at first I didn't think too much of it, but gradually more and more cultures failed until eventually ... nothing. At the same time, the melanogaster cultures were fine.

I'm at a loss to explain what has happened and I'm presently waiting for new cultures set up with a fresh strain of large flies to start producing - so any ideas would be welcome.

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Someone just told me:

Time flies like an arrow. Fruit flies like a banana.

I'm not sure that helps :-)

Frog of the Day: Vietnamese Mossy Frog

The Vietnamese mossy frog (Theloderma corticale), is found in limestone areas in north Vietnam, and seems to have quite a hold on frog fanciers. Largely nocturnal and relying on its camouflage during the hours of daylight, this frog is relatively easy to care for, but not yet commonly bred in captivity. Personally, I like my frogs a little more active while I'm awake.

Neurergus kaiseri - chow time

My Neurergus kaiseri from this year's spawning are coming on well. Here they are chowing down on white woodlice:

If you're interested in aquiring some Neurergus kaiseri, look here.

I like big frogs and I cannot lie

Over the past few months, I've been carrying out the painful process of downsizing my collection of amphibians somewhat. I'm not giving up, but life sometimes seems to be too hectic, and since caring for the animals is something I will never skimp on, frequently there just don't seem to be enough hours in the day.

After finally making the painful decision, I decided the best way to go was species by species. The only question then was - which ones?

Over the past year, many UK froggers seem to have become obsessed with "thumbnail" species, paying silly money for unseen frogs and turning up their noses at anything which doesn't go under the name pumilio. I see some evidence of the same trend in the USA on Dendroboard. Faced with the choice of what to keep and what to rehome, it didn't take me long to make some decisions. Was I going to give up my azureus, my tinctorius, and even my leucomelas? Nope. When it came to the crunch, for me it had to be the amazonicus and the pumilio which went. Giving up the amazonicus was particularly hard, since the vivarium they were in displayed them nicely, and when the early morning sunlight caught their colours, they were stunning. But they had to go.

And difficult though it was, it was worth it. Life post-thumbnails is only slightly less stressful, but more importantly, I'm enjoying my big, beautiful frogs more that I did when I was overstretched.

Think about it. Don't you owe it to yourself, and to your frogs?

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Video of the Day: Dendrobates tinctorius

Nice shots of a young Dendrobates tinctorius by dendrosagu:

Two new species of salamander discovered in Panama

Scientists have discovered two new species of salamanders from the mountainous Costa Rica-Panama border region, pushing the number of salamanders known in the region to 24 and making it a hotspot in terms of salamander biodiversity. Both species are small, slender salamanders that belong to the genus Bolitoglossa and live in tropical montane forest habitat. These salamanders have prehensile tails and are be good climbers.

The first species (Bolitoglossa gomezi) was named in honor of Dr. Luis Diego Gomez, a Costa Rican botanist who was formerly Director of the La Selva Biological Station of the Organization of Tropical Studies. The second species (Bolitoglossa bramei) was named in honor of the late Arden H. Brame, in "recognition of his many contributions to the study of Neotropical salamanders."

I've always fancied trying my luck with some Bolitoglossa, but am put off by the difficulty of mainting them in captivity, mostly due to chytridiomycosis, a deadly fungal disease, which is devastating amphibians in Central America.

Montane Salamanders from the Costa Rica-Panama Border Region, with Descriptions of Two New Species of Bolitoglossa. Copeia, 2007 (3): 556-565.

For sale: Dendrobates leucomelas

I currently have the following frogs for sale (sorry, UK only):

Dendrobates leucomelas: 3-6 months old, currently ~20mm SVL.
Not sexable at this age. £25 each


Email: alan dot cann at gmail dot com

Frog of the Day: Solomon Island Leaf Frog

The Solomon Island leaf frog (Ceratobatrachus guentheri) lives in tropical lowland rainforests on the Solomon Islands and in Papua New Guinea, and is unusual in that it does not go through a tadpole stage in its maturation. Instead, small frogs hatch directly from the eggs which are laid in damp depressions in the ground.

Photo by Tad 20D.

Tylototriton kweichowensis

The latest addition to my menagerie is a small group of Tylototriton kweichowensis larvae, courtesy of Andy.
This species comes from the Chinese provinces of Yunnan and Guizhou (Kweichow) and is found around 2000 metres above sea level, hence they prefer moderate temperatures.
They're presently in a 60x30x30 cm aquarium with lots of aquatic plants and are feeding well on Daphnia and whiteworms.
Over the coming months I hope to document the progression of this group of larvae here on this blog, so keep reading.

Frogs of the Day: Mamiraua Reserve, Amazonas, Brazil

A couple of interesting tree frogs from Mamiraua Reserve, Amazonas, Brazil, courtesy of wquatman.

Hyla leucophyllata:

Hyla punctata:

And the winner is ...

Dunk, who correctly guessed that the answer to last week's competition was Dendrobates azureus:

Kudos to Dunk, and I can see I'm going to have to make the next competition harder!

The first rule of fight club is

dartfrogs will fight!
Watch these videos of Dendrobates auratus and Dendrobates pumilio fighting then choose your vivarium inhabitants with care!

Dendrobates auratus video:

Dendrobates pumilio video: