Characterization and development of courtship in zebrafish, Danio rerio.

Zebrafish, Danio rerio, is introduced here as a useful organism for investigating teleost courtship display and its development. Pair matings of adult zebrafish confirmed that the courtship behavior sequence fell into three general phases: initiatory, receptive/appetitive, and spawning. The developmental onset of identifiable courtship behaviors was also studied. Interestingly, the progression of behaviors in a typical bout of adult courtship was found to recapitulate the ontogeny of the courtship components as they were first expressed in juvenile fish. This finding suggests that the systems controlling the maturation and sequential expression of behaviors stimulated the expression of the later ones. This idea is consistent with the finding that courtship displays of immature fish were stimulated if they were housed with adults for a short period of time. This characterization of courtship display in zebrafish, including its development, opens the door to a forward genetic analysis of vertebrate reproductive behavior.