An update from EDGE Fellow Claudio Soto-Azat
Darwin’s frogs (Rhinoderma darwinii and R. rufum) are two endangered amphibians species only known from the temperate native forests of central and Southern Chile. These are the only amphibians, within the > 6,600 species, which has developed a unique strategy of parental care. Males are able to ingest their recently hatched tadpoles into a specialized structure, known as the vocal sac, and take care from 1 to 19 developing tadpoles for a period of around five to six weeks. Along with seahorses (genus Hippocampus), these are the only organisms of the animal kingdom where males are able to get “pregnant” and therefore take care of their developing offspring and release small replicas of the adults.
During August 2010, I decided to follow Darwin’s frogs to Europe. How? You may ask. This is, because in some European museums are found the largest collections of archived Darwin’s frogs. Therefore, I examined hundreds of individuals kept at the Natural History Museum in London, Alexander Koenig Museum in Bonn and the Museum of Zoology in Hamburg. The individuals examined were originally collected from 1835 to 2007, and included some of the frogs collected by Charles Darwin itself, while in southern Chile, during his epic voyage in the HMS Beagle under the command of Captain Fitz Roy. These specimens brought to Europe, allowed the French zoologists André Marie Constant Duméril y Gabriel Bibron in 1841 to describe the species for the first time and give its name, R. darwinii, in honour to the famous British naturalist. We were able to identify (and re-classify) over 50 new individuals of the northern Darwin’s frog (R. Rufum), finding which increase the current knowledge of this potentially extinct frog.
While at the Alexander Koenig Museum – Bonn, I was received by Dr. Klaus Busse, one of the most knowledgeable persons about Darwin’s frogs. Klaus successfully kept R. darwinii at the Alexander Koenig Museum for 20 years, until all frogs died in 2004 and 2007 possibly from chytridiomycosis. Thanks to his knowledge, now in Chile there are two projects which are successfully breeding Darwin’s frogs at University of Concepción and National Zoo of Chile.
We took a non-invasive skin sample from all individuals, and analyzed them at the Institute of Zoology, Zoological Society of London, in order to study the historic presence of Batrachochytrium dendrobatidis (Bd) infection (causing chytridiomycosis) in Darwin’s frogs. I also learnt techniques to isolate and culture Bd in the laboratory. I will try to implement these in our laboratory of Ecosystem Health, to complement our chytridiomycosis studies in Chile.
By the end of this successful month of research abroad, I participated in the Third Biennial Ecohealth Conference: “Global Ecohealth Challenges; Multiple Perspectives”, held at the London School of Hygiene & Tropical Medicine. This meeting brought more than 200 people from all parts of the world, including: scientists, conservationists, activists and policy makers, which discussed for 3 days different aspects on ecology, animal and human health, social justice, etc. In this important meeting I gave the talk: “An invasive frog and endemic threatened amphibians: impacts of chytridiomycosis in Chile”.
This was a very successful research month where I was able to raise concern on Darwin’s frogs conservation and I could gather important information for the research I lead.