Further classification of skin alkaloids from neotropical poison frogs (dendrobatidae), with a general survey of toxic/noxious substances in the amphibia

A small Neotropical frog, Dendrobates pumilio, undergoes interpopulational variation in color, degree of toxicity, size, and habits. Differences in body coloration encompass the visible spectrum from red to blue, as well as achromatic black and white. There are wide variations in the degree of toxicity, but these variations are not correlated with supposed warning colors. Extracts of skin yield two toxic compounds characterized as steroidal alkaloids with molecular formulae C(19)H(33)NO(2) and C(l9)H(33)NO(3). The rapid rate of divergent evolution among populations of this frog may result from isolation and chance restriction of original heterozygosity, with subsequent selection acting on different and greatly limited mixtures of alleles.

The potent neurotoxin tetrodotoxin, which has previously been found in puffer fish of the order Tetraordontiformes, a goby (Gobius criniger), and the California newt (Taricha torosa), has now been identified in the skins of frogs of the genus Atelopus from Costa Rica.