Atenas Guerrieri, Eslava Nora, González Leo Walter, Guevara Francisco
Rev Biol Trop. 2015 Mar;63(1):189-98. doi: 10.15517/rbt.v63i1.13727.
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 2980 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) = -0.32 year) showed moderately rapid growth. Length frequency data were adjusted to the von Bertalaniffy 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 (theta) 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.
红锯鳞鱼是委内瑞拉东部需求很大的一个物种，但近年来其产量一直在下降。因此，我们的目标是估计这种资源的生长和死亡参数。2011年6月至2012年5月每月进行采样，在埃尔蒂拉诺和阿巴霍港共获得2980个样本。记录了每个样本的全长（厘米）、总重（克）和性别。在长度方面未显示出两性异形（t(S)=1.113，p>0.05），因此为两性建立了一个长度-重量比（Wt=0.0612*Lt(2.54)）；并且两者均表现出轻微的异速生长。使用FiSAT软件通过分析长度频率分布来估计生长情况。估计的生长参数（L.=39.03厘米，W.=679.60克，k=0.48/年，t(O)= -0.32年）显示生长速度适中。长度频率数据被调整到冯·贝塔朗菲模型，表明在生命的最初几年呈指数趋势加速生长，随后生长缓慢，直到鱼达到其最大长度。生长指数（theta）的变异系数表明生长模式没有差异。自然死亡率（M=0.97/年）、捕捞死亡率（F=1.57/年）和总死亡率（Z=2.54/年）都很高，开发率（E=0.62/年）也很高。我们得出结论，红锯鳞鱼已被个体渔民充分开发，并建议持续研究种群动态，以推荐渔业的最佳管理技术。
