Palatability of the Larvae of Three Species of Lithobates

• Published in: Herpetologica Vol. 67; no. 3; pp. 213 - 221
• Main Authors: Szuroczki, Dorina, Richardson, Jean M. L
• Format: Journal Article
• Language: English
• Published: 1011 E. Ash Street, Springfield, IL 62703 The Herpetologists' League, Inc 01.09.2011; Allen Press Inc
• Subjects: Amphibians; Anura; Fish; Fish feeding; Freshwater fishes; Herpetology; Larvae; Learning; Lepomis gibbosus; Predators; Predator–prey interactions; Rana catesbeiana; Skin; Tadpoles; Toxicity; Unpalatability
• ISSN: 0018-0831; 1938-5099
• DOI: 10.1655/HERPETOLOGICA-D-10-00059.1

While unpalatability in general is well-known to provide prey protection against predators, the role of unpalatability as an antipredator mechanism in larval anurans and more specifically, Lithobates catesbeianus (American Bullfrog) larvae remains contentious. There are three major problems associated with the majority of the studies done to date: (1) failure to incorporate the existence of a range of relative preferences or palatability, (2) failure to effectively control for predator hunger levels, and (3) failure to consider confounding variables such as prey behavior and prey appearance. We sought to alleviate these problems by first training Lepomis gibbosus (Pumpkinseed Sunfish) to consume a standardized food ration for 1 wk and then spiking that food ration the following week with only the skin of three different larval anurans that have been hypothesized to range in palatability (namely, L. catesbeianus, L. clamitans [Green Frog], and L. sylvaticus [Wood Frog]). The results of this experiment revealed that a range of palatability does in fact exist, with L. catesbeianus being least palatable, L. clamitans being somewhat unpalatable, and L. sylvaticus being highly palatable. This study was the first to show evidence, devoid of any confounding variables, that L. catesbeianus and, to a lesser extent, L. clamitans tadpoles are unpalatable to sunfish predators.