Reproduction of species of the genus Cichla in a reservoir in Southeastern Brazil

L M Gomiero,F M S Braga

doi:10.1590/s1519-69842004000400008

L M Gomiero, F M S Braga

Open Access

https://doi.org/10.1590/s1519-69842004000400008

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Abstract

The reproduction of two species of Cichla (Cichla cf. ocellaris and C. monoculus, commonly known in Brazil as tucunaré) introduced in the Volta Grande Reservoir, southeastern Brazil, was analyzed. The period for spawning began at the end of the dry season (September) and extended until the end of the rainy season (January). The length of the first gonad maturation (L50) and the length at which all fish are considered adults (L100) were very similar for both species and coincide with the length of fish at one year of age. The analysis of disassociated oocytes evidenced a partitioned spawning, and that C. monoculus was more prolific than C. cf. ocellaris. The low fecundity, partitioned spawning, bi-parental brood care, and supplying of food for the young are related to the way of life, habitat, and reproductive behavior of these fish.

Highlights

Increasing electricity demand requires the construction of many hydroelectric plants that, as a result of river damming, have innumerable consequences for fish populations
For C. monoculus there was a prevalence of B stage, but the C stage occurred in all collections, except for the ones made during September 1997 and March 1998
The maturation stages showed that C-stage individuals could be found during throughout the seasons, but reproduction occurred mainly from September to January

Summary

Introduction

Increasing electricity demand requires the construction of many hydroelectric plants that, as a result of river damming, have innumerable consequences for fish populations. A unavoidable result with respect to aquatic fauna is the alteration in abundance of animal species, with excessive proliferation of some and reduction, or even elimination, of others. The impact level is mainly related to local fauna characteristics, location of the dam with respect to population distribution in the area, morphometrics of the basin, existence of other dams upstream, dam design, and operational procedures of the plant itself (Agostinho, 1994)

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