Taxonomic Diversity of the Fish Community Associated with Soft Bottoms in A Coastal Lagoon of the West Coast of Baja California Sur, Mexico

Abstract

The San Ignacio lagoon is located inside the “Biosphere reserve El Vizcaino”. It is an important area in terms of ecology, biology, fisheries and tourism and is used by many species as feeding and breeding grounds. Therefore, the study of the fish community of this lagoon will bring a better understanding of the role these organisms play in the ecosystem. The aim of this study was to describe the taxonomic diversity of the icthyiofauna associated to soft bottoms. Six bimonthly samplings were carried out from April 2013 to April 2014 in 11 sites, obtaining a total of 66 replicates. An experimental trawl net was used to catch the fish. Physicochemical variables such as water temperature and salinity were recorded at each site. A total of 2,887 organisms were collected, belonging to six families, 38 genera and 46 species. There was a positive correlation between temperature and salinity and a high fish diversity. Families Haemullidae and Serranidae had the higher number of species, five species each, followed by Sciaenidae with four species, and Paralichthydae and Clupeidae, with three species each. Species considered as residents were Pleuronichthys guttulatus , Calamus brchysomus , Chaetodisterus zonatus and Sphoeroides annulatus . Regarding Fisher’s alpha diversity and taxonomic distinctness, both showed differences related to temperature and salinity between months. Despite the fishing activity in this lagoon that takes place most of the year, according to our results of taxonomic distinctness (Δ*) and average taxonomic distinctness (Δ+), there is no evidence of anthropogenic impact in this lagoon.