PATRONES LATITUDINALES DE COMPOSICIÓN Y DIVERSIDAD FUNCIONAL DE PECES ASOCIADOS A LA PESCA DE CAMARÓN DEL PACÍFICO MEXICANO

Abstract

ABSTRACT In this research latitudinal composition patterns and taxonomic and functional diversity indicators of the ichtych community of five typical shrimp fisheries zones from the mexican Pacific (northern Gulf of California, Sinaloa-Nayarit coast, Jalisco-Colima, Michoacán-Guerrero and Gulf of Tehuantepec) are contrasted and described for the very first time. Structural descriptors were used for analyses such as composition, taxonomic diversity, and biogeographic affinity; functional such as trophic level, trophic guild, and reproductive guild; associated to habitat like the use of estuarine systems, water column position, and vertical distribution; and morphological descriptors such as fish and caudal fin shapes, among others. General composition was integrated for 2 classes, 20 orders, 65 families, 147 genera, and 292 species. The family with the most species was Sciaenidae with 31. The most frequent genus was Anchoa, with seven species. A high percentage of species present wide distribution ranges (30.2 spp. Cortez Province ~ Panamic P.; 21.3 spp. San Diego Province ~ Panamic P.). Nevertheless, each ecosystem is structured by a characteristic association of species, apparently related to ecosystems physiographical conditions. Species richness presents a pronounced diminishment at northern Gulf of California with warm-temperate characteristics to the Gulf of Tehuantepec with tropical conditions, while taxonomic diversity indicators present an opposite trend. Indicating taxonomic redundancy on tropical zones and larger taxonomic heterogeneity at northern Gulf of California in spite of the lower richness of species. Explained by the prevailing environmental conditions and isolation processes generated during the formation of the Gulf of California. Analyzed functional characters indicate similarity on the functional structure of demersal fishes from the five ecosystems, regardless of considerable differences on richness and taxonomic composition. Ichthyofauna was grouped into 44 functional groups that under a global context present properties from the three functional diversity hypotheses of larger acceptance. Redundant: observed on groups of species dense tropical zones; singular: on groups formed by a single species self characterized; and idiosyncratic: such species that form part of a redundant group of an ecosystem, but that in other is the only representative of a group.