Discovery of skin alkaloids in a miniaturized eleutherodactylid frog from Cuba.
Four phylogenetically independent lineages of frogs are currently known to sequester lipid-soluble skin alkaloids for which a dietary source has been demonstrated. We report here a remarkable fifth such instance, in Eleutherodactylus iberia and Eleutherodactylus orientalis, two species of miniaturized frogs of the family Eleutherodactylidae from Cuba. Six pumiliotoxins and two indolizidines were found in E. iberia, one of the smallest frogs in the world and characterized by a contrasting colour pattern for which we hypothesize an aposematic function. Analyses of stomach content indicated a numerical prevalence of mites with an important proportion of oribatids-a group of arthropods known to contain one of the pumiliotoxins detected in E. iberia. This suggests that miniaturization and specialization to small prey may have favoured the acquisition of dietary skin alkaloids in these amphibians.
División de Colecciones Zoológicas, Instituto de Ecología y Sistemática, Carr de Varona, Capdevila, Boyeros, AP 8029, CP 10800 Ciudad de la Habana, Cuba.
Ariel
A
Rodríguez
Dennis
D
Poth
Stefan
S
Schulz
Miguel
M
Vences
D000470:Alkaloids / Q000032:analysis*; D000664:Amphibian Venoms / Q000032:analysis*; D000818:Animals; D001001:Anura; D003462:Cuba; D004032:Diet; D008297:Male; D008925:Mites; D012867:Skin / Q000737:chemistry*
D000470:Alkaloids; D000664:Amphibian Venoms