PERACARIDS FROM THREE LOW-ENERGY FINE-SAND BEACHES OF MEXICO:WESTERN COAST OF GULF OF CALIFORNIA

摘要

Taxonomic knowledge of species from low-energy sandy beaches is scarce in the literature; in spite of the fact, many phyla inhabit sandy shores. Here,is present peracarid species found from concurrent field sampling on intertidal and subtidal zones on low-energy beaches. We found 59 species of orders Amphipoda, Isopoda, Tanaidacea and Cumacea. Dominant orders were amphipods (39 species) and isopods (9 species). For first time 18 species were cited for Gulf of California beaches and 16 for mexican pacific coast. There were 16 common species shared between different beaches. Cirolanid isopods dominated intertidal and amphipods, cumaceans and tanaids dominated subtidal. Although, tanaids where the more dense group (1191 ind.m~(-2)). Both, number of species and abundance increase from long beaches with fine mineral sands and high organic and silt clay content to small beach with coarse calcareous sand and high slope. Slope varies seasonally according with physical regime of the bay. Patterns of seasonal variation and across shore distribution could not be definite because depend of many variables not studied here, but according with our results some species are distributed both intertidal and subtidal zones.