Mate choice, egg cannibalism and reproductive success in the river bullhead, Cottus gobio L.

Abstract

The seasonal pattern and individual variation in reproductive success was studied in a population of the river bullhead, Cottus gobio L. Female fecundity and male reproductive success were correlated with body size. Large males were found to breed early in the season when most of the large females spawned. The diameter of eggs found in male nests indicates that females tend to mate with males larger than themselves. The analysis of stomach contents suggests that guarding males cannibalize some of their own eggs. During parental care, the rate of filial cannibalism increases as guarding male body condition deteriorates.