Variacion invierno-verano en la distribucion por tallas, sexos y densidad promedio de la langostilla (Pleuroncodes planipes Stimpson, 1860) en la costa occidental de Baja California

In winter (February) the mean size of red crabs increased from south to north (males 23.4-25.3mm, females 22.3-24.0mm standard carapace length). Mean density of red crabs by latitude varied from 50-162 kg/ha, increasing from north to south. The overall sex ratio was near 1:1, and the percentage of gravid females was 70-80%. Bottom temperatures ranged from 13-15°C. During summer, mean size of red crabs increased northward (males 25.15-28.54mm, females 24.13-26.9mm SCL); mean density was 51-662 kg/ha, with larger concentrations at the extreme latitudes (24° and 28°N). The overall sex ratio was almost 1:1. No ovigerous females were found. Bottom temperatures varied from 11-16°C. Differences in mean size and mean density seem to be associated with breeding seasons, bottom temperature, and seasonal upwelling (which determines food availability. In winter, upwelling is less intense and the bottom temperature is more homogeneous than in summer. -from English summary