Fin digging and leaf lifting by the convict cichlid, Cichlasoma nigrofasciatum: examples of parental food provisioning

In fish, the predominant form of parental care is brood defence. The convict cichlid, a biparental fish native to Central America, also engages in two types of brood provisioning: fin digging and leaf lifting. These behaviour patterns were studied in the field, and in outdoor experimental ponds and laboratory aquaria. In the ponds, females fin dug 51 times more often when guarding fry than when unmated; males fin dug three times more frequently when guarding fry than when unmated. After the young became free-swimming, females performed four times (field) and two times (pond and laboratory) more fin digging and twice as many leaf lifts (field) as males. Females in the field increased leaf lifting with brood age but males did not. Fin digging frequency by parental females and males increased with brood age. Frequency of adult feeding bites at the substrate did not change with brood age except in the field, where female feeding bites increased with brood age. In the field, females performed more feeding bites than males but in the laboratory males fed more often than females. Thus changes in fin digging frequency with brood age do not seem to be strongly linked to the feeding requirements of the parents. In the laboratory, fin digging frequency was influenced by substrate quality ( P = 0·08) but not by ration ( P > 0·10). Taken together, these data support the hypothesis that parental fin digging and leaf lifting help increase food availability to their young.