Resumo

GOMEZ, Gabriel; GUZMAN, Ramón  e  CHACON, Ramón. Some aspects of the reproductive and population biology of torrotogrunt, Genyatremus luteus (Bloch, 1797)  (Pisces: Haemulidae), in the Paria gulf, Venezuela. Zootecnia Trop. [online]. 2002, vol.20, n.2, pp.223-234. ISSN 0798-7269.

Torroto grunt, Genyatremus luteus, is a species with fishing interest and a growing commercial value in the artisanal fishery of the Gulf of  Paria. The size structure, size at maturity of 50%, reproductive period and length - weight relationship were studied as fundamental parameters for the study of the reproductive biology, population dynamics and evaluation of this resource. A sample of 500 individuals collected between January and December 1999 was analyzed. Sizes varied between 133 and 388 mm of total length (Tl), with an average of 254 mm. The length - weight (W) relationship did not differ significantly between sexes (P > 0.05), so the common regression was W= 1,009 x 10^-4 * Tl^2,67 , with an allometric relative growth rate (P < 0.05). The estimated size at maturity of 50% was 345 mm Tl for both sexes. Ninety percent of individuals in the sample were below this size. The presence of individuals in advanced maturity stage between January and June, with a higher intensity during February, shows that greater reproductive activity of this species takes place during this period. The size structure and the significant proportion of individuals below the size at maturity of 50%, would reveal an intense fishing activity upon the resource, which suggests that monitoring of this fishery should be maintained in order to improve the knowledge of the biology and dynamics of this resource as fundamental aspects for the definition of managing polices in the gulf of Paria.

Palavras-chave : Torroto grunt; Genyatremus luteus; artisanal fishery; Gulf of Paria; reproductive biology.