Sexual Differences in Offspring Defense in a Monogamous Cichlid Fish

Solitary male and female Texas cichlids, Cichlasoma cyanoguttatum employ different tactics when defending their offspring. Males emphasize the lateral display against an intruder and make infrequent return visits to the young while the intruder is present. The female is more likely to attack, attempting to bite the intruder and also making frequent return visits to the offspring. These differences disappear with increasing age of the offspring as the male becomes more like the female with more violent attacks. Both defense systems appear effective, in the short term, against intruders.