EARLY-SUMMER ICHTHYOPLANKTON BIODIVERSITY ASSOCIATED WITH OCEANIC FACTORS ON THE CONTINENTAL SHELF OF THE SOUTHERN EAST CHINA SEA

Abstract

Ichthyoplankton communities associated with oceanic factors on the continental shelf of the southern East China Sea were studied in early summer 2009. Temperature and salinity of the stations in this survey respectively varied 13.78 similar to 27.86 degrees C and 33.14 similar to 34.77 psu. In total, 1204 fish larval individuals belonging to 62 families and 120 taxa were identified. Using a cluster analysis, the spatial distributions of larval fish were classified into 3 groups: a coastal group, a shelf group, and an offshore group. The offshore group was further divided into 2 subgroups: a mixed shelf group and a Kuroshio group. The coastal group consisted of 5 taxa, namely, sciaenids, gobiids, Cynoglossus joyneri, Engraulis japonicas, and Parapercis spp. The shelf group contained the dominant species Decapterus spp., sciaenids, C. joyneri, gobiids, Bregmaceros spp., Auxis spp., Trachinocephalus myops, and Diaphus A group. The mixed shelf group and the Kuroshio group contained the dominant species of Decapterus spp., and Auxis spp., respectively. Diversity also varied with the situation of the assemblages in that high diversity was found in offshore areas and low diversity was found in coastal areas. Sciaenids and gobiids were abundant in coastal waters; while Decapterus spp. and Auxis spp. were respectively abundant in the mixed shelf waters and the Kuroshio waters.