Crustacean larvae distribution in the coastal upwelling zone off Central Chile

Abstract

We present data on the stage abundance and spatial distribution of 5 taxa of crustacean larvae whose adult populations inhabit different depth ranges in the coastal area of central Chile (35 to 37°S). Our goal was to identify the relationship between the timing and depth range of larval release, with larval depth distribution and behavior, and offshore transport during early upwelling season (November) and upwelling reversal (March). Emerita analoga larvae were mainly released in the intertidal off phase in the season of maximum upwelling intensity. E. analoga was the shallowest larvae in this study, the most widespread in the horizontal plane and no diel vertical migrations were observed. Blepharipoda spinimana, another intertidal species, was always restricted to coastal stations and were mainly released during summer. It is a shallow species and, at our sampling scale, we could not identify vertical behavior. Libidoclaea granaria larvae were released in the continental shelf during the more intense upwelling season (November). Zoea I were widespread horizontally and zoea II appeared closer to the coast. They did not show vertical migration, they were found widespread in the water column and they were the deepest larvae. Larvae that migrated vertically (Neotrypaea uncinata and Pagurus spp.) were released over a long period during the upwelling season (summer months), from the subtidal environment. Sub-surface waters were characterized by low oxygen and low temperature. Larval distribution depended on the spatial structure of upwelling circulation, larval behaviour and physiological tolerances as well as on the depth and timing of larval release. © Inter-Research 2006.