Analysis of chemicals from earthworms and fish that elicit prey attack by ingestively naive garter snakes (Thamnophis)

Abstract

Materials previously shown to elicit increased tongue-flicking and prey attack in garter snakes (Thamnophis sirtalis) were isolated from both earthworms (Lumbricus terrestris) and fish (Pimephales promelas). Both high- and low-molecular-weight components from earthworms and fish stimulated attacks and increased tongue-flicking in previously unfed neonate garter snakes relative to distilled water controls. Earthworm collagen was also effective, but even concentrated fractions were less effective than raw extract. Conflicting reports on the effectiveness of collagen suggest that the salient chemical(s) is a smaller molecule tightly bound to collagen and resisting standard purification methods.

The American Alligator Detects Food Chemicals in Aquatic and Terrestrial Environments

“…Among reptiles, food chemical responses have been examined primarily in snakes and lizards. These studies demonstrate the efficacy of prey extracts in eliciting predatory attack (reviewed in BUKGHARDT 1980, in press), the role of vomeronasal and olfactory chemoreceptors in food recognition (HALPEKN & FKUMIN 1979;HALPEKN 1987), and the nature of chemicals eliciting feeding behavior (WANG et al 1988;SCHELL et al 1990). The use of chenioreception in food recognition by other reptiles has received little attention.…”