Characterization of the Reproductive Behavior and Early Life History Stages of Cichlasoma dimerus (Heckel, 1840)(Perciformes, Cichlidae) under Laboratory Conditions.

MEIJIDE AND G. A. GUERRERO

Porto Alegre, Brasil

Congreso; International Symposium on Phylogeny and Classification of Neotropical Fishes and Neotropical Ichthyological Association 9 th Annual Meeting; 1997

Pontifica Universidade Catolica do Rio Grande do Sul

Cichlidae is a fresh and brackish water family found in Central and South America (one species extending north to Texas), Africa, Madagascar, West Indies, Israel, Syria, coastal India and Sri Lanka. It is a large family that comprises about 105 genera and 1300 species, making it the second largest perciform family. There is a vast literature on the reproductive behavior, most of which describes spawning behavior and parental care, but considering the number of species, their wide distribution and importance, it is surprising that there is little descriptive information on the early development of cichlids. Larval fishes often display characteristic pigment patterns which can be used to identify species at a very early point in their lives. Moreover, early life history characters may be useful in studing intrafamilial relationships. The main objective of this study is to describe the early life history stages of Cichlasoma dimerus. The geographical distribution of this species includes the rivers Paraguay, lower Alto Parana, Parana Medio and Parana Inferior. In addition, the reproductive behavior under laboratory conditions is characterized. Eggs and larvae were obtained from adults captured in Esteros del Riachuelo, Corrientes, Argentina (27º 20’ S, 58º 45’ W). Adults were kept in large aquaria at 25 ± 0.5 ºC and 12:12 hours photoperiod, in which pairs were usually formed. For observation, single pairs were transferred to smaller aquaria with a layer of gravel and smooth stones for egg deposition on the bottom. A part of the fry guarded by parents was sampled day by day. Specimens were observed and measured microscopically. The main morphological and functional features of each stage are described and the hours or days of development determined. Photomicrographs and camera lucida drawings characterize the stages pictorially. The present study was supported by a grant from the University of Buenos Aires (EX 095).