FISH ASSEMBLAGES AROUND ESPIRITU SANTO ISLAND AND ESPIRITU SANTO SEAMOUNT IN THE LOWER GULF OF CALIFORNIA, MEXICO

摘要

Fish composition, abundance, and diversity were recorded by visual censuses at five sites near the Espiritu Santo Island and one near the Espiritu Santo Seamount, and compared to hydrographic parameters (salinity, oxygen, water temperature). Surveys conducted between November 1995 and October 1996 recorded 51,099 fishes, belonging to 41 families, 82 genera, and 120 species. The most common species near the island were: sergeant major, Abudefduf troschelii; Cortez rainbow wrasse, Thalassoma lucasanum; scissortail damselfish, Chromis atrilobata; Cortez damselfish, Stegastes rectifraenum; bluebarred parrotfish, Scarus ghobban; Pacific creolefish, Pamnthias colonus; yellow snapper, Lutjanus argentiventris; Cortez sea chub, Kyphosus elegans; king angelfish, Holacanthus passer; and Mexican goatfish, Mulloidichthys dentatus; whereas in the seamount were: Pacific creolefish; Cortez damselfish; Cortez rainbow wrasse; black skipjack, Euthynnus lineatus; king angelfish; red snapper, Lutjanus peru; yellow snapper, mackerel scad, Decapterus ma-carellus; mullet snapper, Lutjanus aratus; and Mexican goatfish. Fish abundance and diversity changed seasonally between the island and the seamount, mainly related to the topographical differences between the two sites. The island has protected and shallow areas, substrate with small rocks to moderate sandy patches; whereas the seamount is in deep water, has strong currents, large boulders on the benthos, and no protective areas.