Abstract

GUERRIERI, Atenas; ESLAVA, Nora; GONZALEZ, Leo Walter  and  GUEVARA, Francisco. Growth and mortality parameters of Orthopristis ruber (Perciformes: Haemulidae) from Los Frailes Archipelago, Venezuela. Rev. biol. trop [online]. 2015, vol.63, n.1, pp.189-198. ISSN 0034-7744.

Orthopristis ruber is a species in high demand in Eastern Venezuela, but production has been decreasing in recent years. For this reason, our objective was to estimate the growth and mortality parameters of this resource. Monthly samples were collected from June 2011 to May 2012, obtaining 2 980 specimens in El Tirano and Puerto Abajo. Data on total length (cm), total weight (g), and sex were recorded for each specimen. No sexual dimorphism was shown with respect to length (t_s=1.113, p>0.05), so one length-weight ratio was established for both sexes (Wt=0.0612*Lt^2.54); and they both exhibited minor allometric growth. Growth was estimated by analysis of length frequency distributions using FiSAT software. The estimated growth parameters (L_∞=39.03cm, W_∞=679.60g, k=0.48/year and t_o=-0.32year) showed moderately rapid growth. Length frequency data were adjusted to the von Bertalanffy model, and indicated an exponential tendency of accelerated growth during the first years of life, followed by slow growth until the fish reached its maximum length. The coefficient of variation of the growth index (Ø’) demonstrated no differences in growth pattern. The natural mortality rate (M=0.97/year), from fishing (F=1.57/year), and total mortality (Z=2.54/year), were high, as well as the exploitation rate (E=0.62/year). We concluded that O. ruber has been fully exploited by artisanal fishers, and suggest a continuous study on population dynamics, to recommend optimum management techniques for the fishery.

Keywords : growth; mortality; population parameters; Orthopristis ruber; Los Frailes Archipelago; Venezuela.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )