Differential Predation by Gambusia affinis on the Eggs of Seven Species of Anuran Amphibians

Gambusia affinis starved 1 to 4 days and offered normally deposited eggs of Acris crepitans, Bufo valliceps, Gastrophryne olivacea, Hyla chrysoscelis, Pseudacris clarki, Scaphiopus couchi, or Rana pipiens ate a significantly larger number and volume of eggs of those species which usually breed in temporary as opposed to permanent water. The differential predation seemed to result from the larger, firmer egg capsule of the permanent water breeders acting as a mechanical defense mechanism. There was no evidence of chemical repellents or toxicity in the egg species studied.