Embryonic and larval development of a substrate-brooding cichlid Cichlasoma dimerus (Heckel, 1840) under laboratory conditions

摘要

There is a vast literature on the reproductive behaviour of cichlid fishes, most of which describes spawning strategies and parental care. However, descriptive information on the early development of cichlids is scarce. In this study, embryos and larvae of laboratory-reared Cichlasoma dimerus are described. The early ontogeny is documented from oocyte activation until the beginning of the juvenile period. At a water temperature of 25 ± 0.5 ℃ and a 12:12 h photoperiod, cleavage is finished in 10 h and the first somites appear at 26 h of development. the larvae hatch during the beginning of the third day and are deposited by both parents in a pit they have dug out in advance. Yolk-sac larvae present three pairs of adhesive glands over the head, these transient larval organs being characteristic of substrate-brooding cichlids. After another 5 days, the fry swim freely and begin to feed exogenously. Since the yolk-sac is not completely reabsorbed until 2 or 3 days later, these is a period of combined endogenous and exogenous food supply. The juvenile stage is reached on the 42nd day from spawning.