The project Building a Future for the Amphibians of Madagascar(1) is led in-country by Tsanta Rakotonanahary and Serge Ndriantsoa and funded through the Critical Ecosystem Partnership Fund. A key project aim is to help build and develop networks for amphibian conservation in Madagascar. Research and conservation activities related to the amphibian fungal disease chytridiomycosis are coordinated through the Chytrid Emergency Cell network which this project helps support.
In April 2018 Tsanta and Serge helped facilitate and participated in an international research project “Evaluation of chytridiomycosis affecting amphibians of Madagascar,” led by Professor Mat Fisher from Imperial College London. This project aims to isolate the strain of Bd chytrid fungus present in Madagascar as part of a global study. This blog explains what they did there.
After various administrative formalities with regional authorities of Marovoay and Majunga, we were able to start working. The site of the field work was Ankarafantsika National Park, located in the north-west of the country.
Ankarafantsika, also known as the kingdom of the birds, is dry forest habitat with several lakes that are considered sacred by the local people. These lakes are home to various endemic fauna and flora and used to be the tomb of the royal family in the region.
Our first field site was Lake Antsahabe, a small lake behind the restaurant where crocodiles are present (yes, crocodiles!). But don’t worry; we didn’t compromise our safety for science. We collected adult frogs and tadpoles to isolate the pathogen causing chytridiomycosis locally. We also found freshwater turtles: Erymnochelys madagascariensis, which are endemic to the northwest to south-west of the Big Island. Several species of frogs were collected including Heterixalus luteostriatus, Mantidactylus ulcerosus, Boophis doulioti, but the majority were the common and widespread Ptychadena mascareniensis. Tadpoles were caught using a net and adult frogs were caught by hand. We’ve been catching frogs and tadpoles this way for several years now, so it was not very difficult to meet our target of 50 animals for the beginning. We were also lucky with the weather as it was raining and so the frogs were active, which made our job much easier.
In the following days, we visited the rice fields in and around the National Park. One of the things that surprised us a lot is the water temperature at which the tadpoles in the rice fields live. Usually, tadpoles won’t survive in the temperature about 42 degrees Celsius but in Ankarafantsika, they do, and they are very active.
After catching frogs and tadpoles, they were brought to the laboratory facility of Durrell Wildlife Conservation Trust at Ankarafantsika for swabbing. This is done with a special sterile cotton bud, wiping it over the frog’s skin. Professor Mat Fisher and his team aim to grow up the Bd chytrid fungus in their lab in London if the pathogen is present. Bd chytrid attacks the keratin layer of the frog skin, so, we swab the buccal disque of the tadpoles and the belly, legs and palms of the adults.
These parts of the animals are the most keratin rich. As a reminder, chytridiomycosis is an infectious disease affecting frogs and salamanders and is already causing massive mortalities worldwide. Although the Bd chytrid fungus has been detected in Madagascar the disease itself has not yet been declared so this work is important in identifying the strain present and potential risk to Madagascar’s unique frog fauna. Professor Mat Fisher said that Ankarafantsika has been his favourite site in Madagascar so far, given the facilities there. The laboratory is a few steps from the field, the amphibian collection sites are nearby and the people working there are so welcoming and helpful. If the lab work manages to isolate the fungus we will return later this year to collect more samples.
Note: Results from the study looking at global chytrid strains, to which this work will add, has recently been published in Science.
1. Building a Future for the Amphibians of Madagascar is a collaborative project between Amphibian Survival Alliance, Durrell Wildlife Conservation Trust, Global Wildlife Conservation and Amphibian Specialist Group Madagascar