Filial cannibalism in a paternal mouthbrooding fish in relation to mate availability

摘要

Cannibalism of the entire brood by mouthbrooding males was observed in the cardinal fish, Apogon doederleini, in warm temperate waters of southern Japan. This filial cannibalism always occurred within a day of spawning. Males preferentially ate broods produced by females smaller than themselves and by non-resident females, and always changed mates after cannibalism. Cannibalistic males re-mated more quickly than males whose broods were experimentally removed. These results indicate that cannibalistic males take advantage of multiple mate availability, by eating the first brood and rearing the second. It is suggested that filial cannibalism in this fish is associated with mating strategies of females that can shorten inter-spawning intervals by changing mates.