Agonistic Behavior of Captive Goldeye (Hiodon alosoides)

Abstract

Captive goldeye (Hiodon alosoides) (ages 0, I, V–VIII) in clearwater tanks demonstrated a well-developed agonistic repertoire which included charging, chasing, nipping, and lateral displays. We postulate that this agonistic behavior serves as a spacing mechanism in goldeye ecology, allowing fish to defend an individual distance or territory. Age 0 and age I fish showed higher frequencies of direct attack than adults (> age V) which used displays more frequently. In paired encounters, females, smaller fish, and introduced fish won more fights than males, larger fish, or resident fish, a situation which differs from the usually accepted relationships between fighting success and size, sex, or residency. Ripe adults were less aggressive than nonripe adults.