Impending conservation crisis for Southeast Asian amphibians.

With an understudied amphibian fauna, the highest deforestation rate on the planet and high harvesting pressures, Southeast Asian amphibians are facing a conservation crisis. Owing to the overriding threat of habitat loss, the most critical conservation action required is the identification and strict protection of habitat assessed as having high amphibian species diversity and/or representing distinctive regional amphibian faunas. Long-term population monitoring, enhanced survey efforts, collection of basic biological and ecological information, continued taxonomic research and evaluation of the impact of commercial trade for food, medicine and pets are also needed. Strong involvement of regional stakeholders, students and professionals is essential to accomplish these actions.

Biologically active substances from amphibians: preliminary studies on anurans from twenty-one genera of Thailand.

Amphibian skin has been the source of a wide variety of biologically active substances, but less than one-third of the known genera of amphibians have been probed for such active substances. Skins of 21 genera of anurans from Thailand have now been investigated for noxious secretions, toxic substances, and alkaloids. Four genera of bufonid toads (Bufo, Ansonia, Leptophryne, Pedostipes) were toxic due to the presence of bufadienolides or bufadienolide-like compounds. Two species of ranid frogs (Rana raniceps, Rana signata) were toxic, perhaps due to the presence of toxic peptide(s). Two species of rhacophorid frogs (Polypedates) were slightly noxious/toxic. One species of microhylid frog (Kaloula pulchra) was noxious. Trace amounts of pumiliotoxin alkaloids were detected in a ranid frog (Limnonectes kuhli). A further 18 species did not exhibit noxious or toxic properties to a significant extent.