Predatory Responses of Largemouth Bass (Micropterus salmoides) to Conspicuous and Cryptic Hatchling Turtles: A Comparative Experiment

Abstract

Previous experiments have shown that largemouth bass (Micropterus salmoides) avoid feeding on active painted turtle (Chrysemys picta) and red-eared slider (Trachemys scripta) hatchlings. Largemouth bass also develop learned avoidance to all hatchlings (dead, anesthetized, or active) of these species after just one experience with an active hatchling by associating the bright plastral colors and patterns of these species with the defensive behaviors of the hatchlings. It has not been determined whether largemouth bass respond similarly to cryptic snapping turtles. The categorical feeding responses (avoided, rejected, or eaten), quantitative feeding behaviors, and learning capabilities of largemouth bass to conspicuously colored painted turtle and cryptic common snapping turtle (Chelydra serpentina) hatchlings were examined in this experiment. Significantly more active painted turtles were avoided, rather than rejected, when compared with all other hatchling treatments. Significantlymore active snapping turtle hatchlings were rejected, rather than avoided, when compared with dead or anesthetized snapping turtles. There were also significant differences in the quantitatively defined feeding behaviors (e.g., number of repeated attacks and rejections, intensity of response, and length of handling time per hatchling presentation) for largemouth bass that preyed on painted and snapping turtles. Neither positive nor negative learning of hatchling painted and snapping turtle prey occurred over time in this experiment. These results are consistent with the hypothesis that the conspicuous form of a noxious (chemical, morphological, or behavioral) prey item will have a higher survival rate than a cryptic, noxious prey.