Seasonal Succession of Free-Swimming Perciform Larvae in Lake Opinicon, Ontario

Abstract

Free-swimming larvae of five perciform species were collected with tow nets in large numbers in Lake Opinicon from May to August of 1969 and 1970. The species appeared in the same seasonal sequence during the 2 yr: first yellow perch (Perca flavescens) followed by logperch (Percina caprodes), black crappies (Pomoxis nigromaculatus), and pumpkinseeds and bluegills (Lepomis gibbosus and L. macrochirus). Peaks of larval abundance, and also hatching, occurred earlier in 1970, when nest-site temperatures from early May to mid-June showed faster lake warm-up than in 1969.