Population features of Hoplosternum littorale (Hancock, 1828) (Siluriformes, Callichthyidae) at Santo Anastacio Reservoir, Brazil

摘要

Objective. The length-weight relationship and condition factor of fish are indicators of physiological well-being and may be related to reproduction and feeding periods. These attributes were evaluated for a population of Hoplosternum littorale sampled in the Santo Anastácio Reservoir (Fortaleza, Northeastern Brazil). Materials and methods. One hundred and fifty-five specimens were collected with gillnets between October 2009 and March 2010, and standard length (cm), total weight (g), sex and gonadal maturation stage were registered. Results. The observed length-weight relationship indicated negative allometric adjustment (2.72). Only seventy individuals were evaluated for the condition factor analysis, sexual determination and gonadal state classification. Condition factor values peaked in November and plummeted in February, no statistical differences in sex ratio (χ2=13.683; p=0.057) were observed. Mature females were collected throughout the study period. Conclusions. The results indicate that the population of H. littorale in the Santo Anastácio reservoir presents growth deficiency and changes in reproductive strategy in this hypereutrophic environment.