摘要：WE ANALYZED THE COMPOSITION, DIVERSITY, AND ABUNDANCE OF MARINE FISH AT ROCKY REEFS OFF SAN JOSÉ ISLAND, MEXICO BETWEEN OCTOBER 2001 AND AUGUST 2002. FISH SPECIES WERE RECORDED USING A VISUAL CENSUS IN 5 SAMPLING AREAS OF 50 BY 5 METERS AT 2 DEPTHS, SHALLOW (1-3 METERS) AND INTERMEDIATE (5-7 METERS). A TOTAL OF 26 946 ORGANISMS WERE COUNTED, BELONGING TO 84 SPECIES. THE FAMILIES SERRANIDAE (9 SPECIES), LABRIDAE (8), POMACENTRIDAE (7), AND HAEMULIDAE (6) WERE THE MOST REPRESENTATIVE. WE MEASURED THE RUGOSITY OF THE BOTTOM SURFACE, WHICH SHOWED A POSITIVE RELATIONSHIP WITH ABUNDANCE, RICHNESS, AND FISH DIVERSITY. THE OCEAN BOTTOM OFF SAN JOSÉ ISLAND IS COVERED WITH VARIOUS SIZE ROCKS THAT OFFER MORE FEEDING AND REFUGE AREAS TO FISH ASSEMBLAGES THAN OTHER AREAS. THE ECOLOGICAL INDEX INCREASED DURING THE WARM SEASON. DIVERSITY AND RICHNESS SHOWED SIGNIFICANT VARIATIONS (P
关键词：fish diversity;rocky reef;Baja California Sur;Gulf of California;diversidad de peces;arrecifes rocosos;Baja California Sur;golfo de California
