Species composition and resource density of necton in Qinzhou Maowei Gulf of Guangxi

Based on the survey data in Qinzhou Maowei Gulf of Guangxi in wet and dry seasons in 2011, we analyzed the species composition and resources density of nekton in that area. The results show that there were 113 species of necton belonging to 86 genus, 54 families, 19 orders. Among them, 76 species of fish accounting for 67.26% of the total species belonged to 65 genus, 39 families, 13 orders. There were 29 species of crustacean accounting for 25.66% of the total species which belonged to 15 genus, 10 families, 2 orders. There were 7 species of cephalopoda accounting for 6.20% of the total species which belonged to 5 genus, 4 families, 3 orders. There was 1 species of merostomata accounting for 0.88% of the total species which belonged to 1 genus, 1 families, 1 orders. The necton mostly belonged to the fauna of Indian-Pacific. The fish all belonged to osteichthyes. The dominant fish species were warm-water (88.16%), then warm-temperate (11.84%), no cold-temperate. The dominant crustacean and cephalopoda species were warm-water, then eurythermal, warm-temperate, no cold-temperate. The resource density of nekton presentedobvious seasonal variation, and the weight density was significantly higher in dry season (25 977.37 kgkm-3) than that in wet season (15 249.49 kgkm-3), but individuality density was significantly higher in wet season (3 825 446 indkm-3) than that in dry season (1 889 575 indkm-3).