Absence of skin alkaloids in captive-raised Madagascan mantelline frogs (Mantella) and sequestration of dietary alkaloids.

Mantelline frogs of the genus Mantella contain a variety of pumiliotoxin, allopumiliotoxin and homopumiliotoxin alkaloids in their skin. Pyrrolizidines, indolizidines and quinolizidines are also present. In contrast, captive-raised frogs (Mantella aurantiaca) have no alkaloids detectable in skin extracts. Frogs fed alkaloid-dusted fruit flies accumulate alkaloids into their skin. Thus, these mantelline frogs, like the neotropical dendrobatid frogs, appear dependent on dietary sources for their skin alkaloids and have the requisite alkaloid-sequestering system(s).