Distribution and density of juveniles of Lutjanus peru (Nichols and Murphy, 1922) (Pisces : Lutjanidae) on the coast of Jalisco and Colima, Mexico

The abundance and bathymetric distribution of juveniles of Lutjanus peru on the continental shelf of Jalisco and Colima, Mexico, were analyzed. Shrimp trawl samples were taken from three expeditions during one year. A total o f 641 juveniles of L. peru were caught, ranging in total length from 3.7 to 21.9 cm and in weight from 0.6 to 153 g. The juveniles exhibited an aggreg ate spatial distribution pattern. Significant differences were observed in the bathymetric distribution of the organisms, since their occurrence was l imited to shallow waters between 20 and 40 m depth. Two size classes were i dentified during the May-June cruise (DEM I) and the March cruise (DEM III) , but only one class was found in the November-December cruise (DEM II). Ac cording to the growth model known for the species, the two size classes fou nd could be of 1 and 1.5 years, respectively. Significant differences were observed in the individual sizes and weights among sites during DEM I and D EM III, whereas the average sizes and weights of DEM II were homogeneous am ong sites. The juveniles presented isometric growth in the size ranges anal yzed.