Brood Cycle Research Articles

Parental behaviour and recognition of young in Cichlasoma biocellatum

1. 1. Six pairs of Cichlasoma biocellatum raised their own first spawn for 18–29 days and next in sequence reared foster schools of Aequidens portalegrensis for equivalent periods of time. 2. 2. Two mixed schools developed when the pair's own embryos were overlooked during exchanges. Parents did not eliminate either kind of young from the mixture. Interspecific, predatory competition between the young was detected within three weeks. 3. 3. The parental cycles of the two species were closely similar. Eggs hatched in 52 hours and the young schooled 96 hours later (total preswimming time: 148 hours at about 82 °F). 4. 4. This correspondence of development and concomitant similarity of the brooding cycles of the two species may account for the success of exchanges. 5. 5. Therefore the reputed ability of cichlid parents to distinguish their own young from those of other species may depend on disparity between the host pair's parental cycle and the stage of development of the foreign young.

Parental Behavior and Imprinting in Cichlid Fishes

AbstractThe brooding cycles of Hemichromis bimaculatus and Aequidens portalegrensis are very similar in timing except that the latter have a longer pit young stage. Exchanges of eggs or wrigglers between the two species resulted in ready acceptance of foreign young. Experienced as well as inexperienced pairs raised foreign spawn successfully in alternation with their own or were induced to brood mixed schools. Acceptance of eggs, wrigglers or free-swimming young was limited to those individuals, regardless of species, which matched in age and behavior the parents' brooding phase. Therefore, it is concluded that parent H. bimaculatus and A. portalegrensis are not imprinted on the species characteristic of their first or subsequent young. Instead, there appears to be an internal mechanism regulating the duration of the phases of parental care, that limits the responsiveness of the parents to particular stages of young.