Distribution and Feeding Strategy of Auxis Spp. Larvae and Its Relation with Eddies in the Gulf of California

The early stages of development through a fish life are highly sensitive to the environmental variability and the food supply. Previous studies in the Gulf of California have defined fish larval habitats, with physical and chemical characteristics, in areas influenced by mesoscale processes. High larval abundance of Auxis spp. was collected in summer 2011 and 2012, showing its preference for certain larval habitats. The aim of this study is to describe aspects about feeding habits of Auxis spp. larvae across previously detected mesoscale cyclonic eddies. In each station, CTD data and zooplankton samples were obtained using opening-closing nets (up and belong thermocline). Higher abundances of Auxis spp. larvae were located over the thermocline and the surface at the edge of the eddy compared to the center. For the stomach content analysis 598 larvae were considered. In surface waters, larvae ingested crustaceans, polychaete and appendicularians. We expect higher feeding intensity in the larvae located over the thermocline, which is its preferential habitat, where high chlorophyll concentrations and zooplankton biomass were recorded, and then generate a concepts model that explain the feeding strategy of Auxis spp. larvae in mesoscale processes.