The reproductive behavior of Aequidens paraguayensis (Pisces, Cichlidae).

The reproductive behaviour of aquarium-held Aequidens paraguayensis is described, with emphasis on a quantitative comparison of female-male parental roles. It is a biparental species. Eggs, laid on leaf litter, are guarded and aerated for about 32 hours (25--27 degrees C) and newly-hatched young are orally brooded for several days. Both sexes performed all parental activities; female-female did more fanning and mouthing of eggs, male-male more oral churning of young initially. The combination of substrate and oral brooding of young by both parents is rare among New World cichlids and is of interest for the study of the evolution of parental behaviour in fishes.