| COMMUNITY STRUCTURE AND LARVAL FISH ASSEMBLAGES IN THE GULF OF CALIFORNIA (JUNE 1998 AND AUGUST 2000) |
| Renteria-Cano, M., Sánchez-Velasco, L. and PEGUERO-ICAZA M., Centro Interdisciplinario de Ciencias Marinas. Ave. Instituto Politecnico Nacional. Col. Playa Palo de Santa Rita CP 23090, La Paz BCS, Mex. MRC mrenteria@ipn.mx.
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| The Gulf of California is characterized by its great fishery and ecology importance. The aim of this study is to known the community structure and larval fish assemblages in the Gulf of California during June 1998 and August 2000. In June, the sea surface temperature fluctuated from 21 to 29 oC and the zooplanktonic biomass from 142 to 1853 ml/1000 m3. One hundred fourteen taxa included in fivety two families were identified. The most abundant families were Myctophidae (47%), Phosichthyidae (17%) and Clupeidae (14%). In August, the sea surface temperature fluctuated from 26 to 31 oC and the zooplanktonic biomass from 99 to 498 ml/1000 m3. One hundred five taxa included in fifty four families were found. Clupeidae (48%) and Myctophidae (27%) were the dominant families. The specific richness, Shannon-Wiener diversity and Pielou justness were higher in June than August; and the Sorensen coefficient (0.43) and the Wilson and Schmida indices (0.56) showed a replacement of fifty percent of community. Bray-Curtis dissimilarity index defined three larval fish assemblages in June. One of them located around the Isla Angel de La Guarda and Tiburon, and the others on the central Gulf eastern and western coasts. The mesopelagic larvae, Benthosema panamense and Vinciguerria lucetia dominated the three assemblages, but varying in frequency and abundance and species associated. In August, two larval assemblages were found, one of them, on the island zone and the other on the central Gulf. These were dominated by B. panamense and Opisthonema libertate larvae. A discriminant analysis defined to the temperature as the variable with major influence on the assemblages, coinciding with the satellite data. The differences between both cruises are influenced by the seasonal changes, being June an early summer and August a last summer.
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