Abundance and biomass of meiobenthos in the spawning ground of anchovy (Engraulis japanicus) in the southern Huanghai Sea

摘要

A grid of 22 stations, giving a broad coverage of the spawning ground of anchovy in the southern Huanghai Sea was selected. Undisturbed sediments were taken from sampling stations during the cruise in June 2003. The average abundance of meiofauna is (1 584 + 686) ind./10cm~2, with corresponding biomass (dwt) of (1 086 ±425) μg/10cm~2. The pattern of abundance of meiofauna is similar to the pattern of biomass. There are 65.88% meiofauna in 0～2 cm sediments, 27.66% in 2～5 cm sediments and 6.47% in 5～8 cm sediments. The Spearman correlation analysis between meiofauna and environmental factors shows that abundance of meiofauna, free living marine nematodes, benthic copepods has significant positive correlations with Chl-a. And the abundance of copepods has significant positive correlations with several factors such as Chl-a, Pha-a, Chl-a plus Pha-a and organic matter. A total of 18 meiofauna groups are i-dentified. Nematode is the most dominant group, average abundance (1 404+670) ind/10cm~2, accounting for 88.65%, and the following groups are also important: benthic copepods (5.48%), kinorhyncha (1.26%), polychaeta (1.07%). By biomass, dominant groups are nematodes (51.72%), polychaeta (21.84%), copepods (14.87%), ostracoda (4.92%), kinorhyncha (3.67%). A total of 90 species of nematodes are identified. The species composition of nematodes is listed based on selected two stations 7794 (coastal area) and 10694 (cold water mass in deep waters).