Comparative fecundity and egg survival of coho salmon (Oncorhynchus kisutch Walbaum) from lakes Ontario, Erie, and Michigan

Abstract

Survival to hatch in 1982 of coho salmon (Oncorhynchus kisutch Walbaum) collected from two Lake Ontario stocks (Salmon River, New York, and Credit River, Ontario) and Lake Michigan and Lake Erie stocks in 1982 was 79, 86, 78 and 24%, respectively; eggs taken from smaller females (<2 kg) of the Lake Erie stock had a significantly lower survival (9%) than those of larger females (>2 kg). Poor fertilization success appeared to be the major cause of low survival to hatch of Lake Erie coho salmon eggs. There were no significant differences in egg size, embryo size, or development time to hatch, step E47, or first exogenous feeding in the four stocks studied, although the incidence of alevin deformity was significantly higher in the Lake Erie coho salmon than in the Lake Ontario or Lake Michigan stocks. Posthatch mortalities were low, except in the case of the Credit River (Lake Ontario) stock, which suffered an epizootic of a suspect viral disease that increased mortality 3 weeks after hatch.