99.3 Saturday, Jan. 7 Predation in the strawberry poison frog Oophaga pumilio: Are adults and juveniles equally protected from ctenid spiders? MURRAY, Erin M.*; SAPORITO, Ralph A.; Missouri State University; John Carroll University Erin1989@live.missouristate.edu
Many organisms possess defensive mechanisms to protect themselves from predation. Dendrobatid frogs, such as Oophaga pumilio, contain alkaloid chemical defenses and advertise their toxicity to predators with warning coloration. However, color signals are not useful for deterring color-blind predators, and little is known about how O. pumilio advertise their chemical defenses to these potential predators. The neotropical ant Paraponera clavata and ctenid spider Cupiennius coccineus are two invertebrate, color-blind predators that avoid adult O. pumilio but readily consume non-toxic frogs. Juvenile O. pumilio possess the same warning coloration as adult O. pumilio, despite being less toxic than adults. This may give juvenile O. pumilio protection from color-visioned predators, while leaving them susceptible to predation by color-blind predators. To test this hypothesis, we presented adults and juveniles of both Craugastor bransfordii, a non-toxic brown frog, and O. pumilio to C. coccineus while they were hunting in the field. Cupiennius coccineus did not consume any O. pumilio adults or juveniles, but consumed 90% of all juvenile and adult C. bransfordii. Therefore, species, but not age, was a significant predictor of predation. Cupiennius coccineus does not appear to be a natural predator of O. pumilio, as both juvenile and adult O. pumilio were equally defended from predation. This provides evidence for the use of alkaloids in O. pumilio as a strong chemical signal against some invertebrate, color-blind predators.