Reproductive behavior of the Greater Redhorse, Moxostoma valenciennesi, in the Thousand Islands region

Abstract

Reproductive behavior was observed in the Thousand Islands region, upper St. Lawrence R. during 3 spawning seasons. Spawning occurred in a 2-wk period from late June to early July, with water temperatures 16-19 C. Males congregated in shallow runs of sand, gravel, and small rubble substrate, where they generally moved about slowly and frequently nudged and gently pushed one another. Females entered spawning areas generally only when apparently ready to spawn and did not initiate agonistic behavior. Females selected spawning sites, usually gravel. Typical spawning acts involved one female flanked on each side by a male; other males often attempted to join the trio. No nest construction or parental care occurred. American eels (Anguilla rostrata) , fallfish (Semotilus corporalis) , and yellow perch (Perca flavescens) preyed on redhorse eggs