VARIACIÓN INTERANUAL DE LAS LARVAS DE PECES PELÁGICOS MENORES EN EL GOLFO DE CALIFORNIA, Y SU RELACIÓN CON EL ZOOPLANCTON Y EL AMBIENTE DURANTE MARZO DE 2005 Y 2006

Abstract

ABSTRACT Despite the importance of the fisheries of small pelagic species in the Gulf of California, Mexico, the studies aimed to evaluate the interactions between their larvae and other groups of zooplankton are scarce. In the present work, the habitat for the development of the larvae was characterized by analyzing the environment and the zooplankton community. During the oceanographic expeditions, 39 stations were analyzed in March of 2005 and March 2006 by standard Bongo net tows and CTD deployments. During March of 2005, the dominant groups were Copepods which accounted for a 46.00%, followed by Chaetognates (27.00%), Euphausids (5.50%), and Ostracoda (1.70%). During 2006 the dominant groups were Copepods (63.50%) followed by Chaetognates (10.60%), Euphausids (7.90%), and Thaliaceans with 7.80%. During 2005, 90% of the ichtyoplankton abundance was represented by 7 taxa and by 9 taxa during 2006, being the mesopelagic Vincigerria lucetia the most important with 36.70% and 24.30%, respectively. In 2005 five species of small pelagic fishes acconted for the 90% of the abundance: Engraulis mordax (78.20%), Scomber japonicus (15.70%), Etrumeus teres (4.10%), Sardinops sagax (1.50%), and Ophistonema spp with (0.40%), while in 2006 S. sagax (31.50%), S. japonicus (26.70%), E. teres (20.90%), and T. symmetricus (12.50%) were the most important. The statistical analysis shows that salinity and temperature gradients are related with the Gulf circulation pattern during that time of the year, and the same was observed for the ichtyoplanktondistribution. The high volumes of zooplankton were related to major chlorophyll-a concentrations and low temperatures. The obtained results support the idea that the successful recruitment of the small pelagic fishes is more related to the community structure than to the environment variability.