Escape efficiency of diploid and polyploid frogs: a comparison of Odontophrynus cultripes (2n = 22) and O. americanus (4n = 44).

The escape efficiency of two closely related species of frogs, Odontophrynus cultripes (2n = 22) and the tetraploid O. americanus (4n = 44), were compared in a shuttle box and under simulated naturalistic conditions. O. americanus was generally superior to O. cultripes, and females tended to outperform males within both species. The relative inefficiency of O. Cultripes escape behavior was examined in light of the animals' having an elaborate, passive defense mechanism in the form of well marked venom glands. Escape efficiency was highly variable in both species. Possessing twice the amount of DNA, the tetraploid behavioral variation was paradoxically less than that of the diploid, but compatible with what has been found for morphological characters in other organisms.