Biological characteristics and spatial-temporal resource distribution of Asian moon scallop, Amusiu pleuronectes in the Beibu Gulf, South China Seain the Beibu Gulf, South China Sea

Through the commercial fishing independent trawlers catch sampling, a total of 794 individuals of Asian moon scallop, Amusiu pleuronectes were collected quarterly from August 2010 to May 2011 in the Beibu Gulf, South China Sea. By biological measurement and resource statistics, the relationship of modality parameters and weight parameters, and the growth and the resource distribution were studied. Results showed that the partial correlation effects of four modality parameters on body weights and adductor weights were as follow in sequence: shell lengths > shell widths > shell heights > hinge ling lengths. Shell lengths, shell widths and shell heights are the most important parameters. Moreover, the mollusk and adductor muscle accounted for almost half of the total body weight and mollusk weight respectively. In summer,the mainly growth was the shell. In spring, the mainly growth was the mollusk part. The resource mainly distributed in the areas of 20?15′N~21?15′N, 108?~109?′E, with the water depth ranging from 20m to 50m and the bottom covered with mud and sand. The spatial distribution showed distinct regularity character. It progressively increased from the south to the north at the latitude, and increased firstly and then decreases from west to east at the longitude. Seasonal variations were also recorded with the peak of summer and the value from spring to winter was 8.72 kg/km2, 13.93 kg/km2, 9.82kg/km2 and 5.90 kg/km2 respectively. Statistics demonstrated that sea surface temperature was the most important environmental factors and has a positive correlation with the average resources density (r=0.972), while salinity and plankton did not show linear correlations.