FILIAL CANNIBALISM IN A PATERNAL MOUTHBROODING FISH IN RELATION TO MATE AVAILABILITY

Cannibalism of the entire brood by mouthbrooding males was observed in the cardinal fish, Apogon doederleini, in warm temperate waters of so uthern 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 male s whose broods were experimentally removed. These results indicate tha t cannibalistic males take advantage of multiple mate availability, by eating the first brood and rearing the second. It is suggested that f ilial cannibalism in this fish is associated with mating strategies of females that can shorten inter-spawning intervals by changing mates. (C) 1996 The Association for the Study of Animal Behaviour