Composición y aspectos biogeográficos del ensamble de peces de la laguna costera Las Guásimas, Sonora, México

We presented the species composition and biogeography at the Las Guásimas Lagoon, located in the central portion of the Gulf of California. We perform seven sampling and the seasonal collections were made with three gear: cast nets, seine and trawl line. We recorded 95 species represented by 16 orders, 38 families and 67 genera. The families in number of species were: Carangidae, Sciaenidae, Haemulidae, Paralichthydae, Engraulidae and Gerreidae. Besides were identified three endemic species of the Gulf of California (Micropogonias megalops, Leuresthes sardina and Pleuronichthys ocellatus). Biogeographic affinity analyzes showed results that indicate a high dominance of species distributed in the Eastern Tropical Pacific (Province of Cortes and Panamic) and transitional species between the California Province and the Eastern Tropical Pacific (ETP). We use previous research on fish in the locality and make a comparison between the previously recorded species and new species observed, using as indicators of vulnerability and resilience. Changes in community structure over time, which might be induced by environmental changes, human activities such as fishing and/or ecosystem dynamics were observed. Most of the species that are new records in the coastal lagoon (84%) they showed moderate to high vulnerabilities, emphasizing the fact of the high importance of the lagoon as a nursery and protection of these species.