南麂岛岩礁潮间带软体动物种类数量变化及其演替

The quantity changes and succession of mollusk species composition in rocky intertidal zones of Nanji Island

为揭示南麂岛岩礁潮间带软体动物种类组成与数量分布及其演替状况,于2013年11月,2014年2月、5月、8月,共4次对南麂岛的潮间带7个断面进行了定量和定性调查,并对软体动物的种类、数量和优势种变化及物种多样性进行了研究。结果显示,共鉴定出软体动物种类63种,隶属于3纲113目34科52属,其平均栖息密度和生物量为506.5个/m2和801.54 g/m2;条纹隔贻贝(Septifer virgatus)是4个季节共有的且优势度最大的优势种;软体动物Shannon-Wiener多样性指数(H')平均值为冬季(1.73)>春季(1.69)>夏季(1.58)>秋季(1.40);与历史资料对比发现,其物种数及生物量有一定程度的减少。研究表明,南麂岛岩礁潮间带的软体动物发育较好,栖息密度和生物量远高于邻近的其他岛屿,但与此前调查结果相比却有所降低。

To reveal the composition, quantity distribution and succession of mollusk species in Nanji Island rocky intertidal zones, quantitative and qualitative surveys were carried out at 7 sections of Nanji Island intertidal zones in November 2013 , February, May, and August 2014, and the species composition, quantity and changes in dominant species, species diversity of mollusks were studied. The results include: ( 1 ) 63 mollusk species were identified belonging to 3 classes, 113 orders, 34 families and 52 genuses, and the average habitat density and average biomass were respectively 506. 5/m2 and 801. 54 g/m2 ; (2) Septifer virgatus was a common dominant species in all four seasons and of the highest dominance among the species researched; (3) The average Mollusks Shannon-Wiener diversity indexes ( Hr) quarterly were, winter (1.73) > spring (1.69) > Summer ( 1.58) > autumn ( 1.40) ; (4) In contrast to the historical data, the species number and biomass of Nanji Island mollusk had decreased. The results suggest that mollusk is welldeveloped in rocky intertidal zones of Nanji Island, with the density and biomass being far higher than that of other neighboring islands, but decreased compared to the data from previous surveys.