浙江沿岸岛礁区潮间带软体动物群落结构研究

Community structure of molluscs in the rock intertidal zone of Zhejiang coast

为研究浙江岛礁区潮间带软体动物群落结构特征,分别于2009年春季（4月）和秋季（10月）对浙江沿岸8个采样点的软体动物开展调查,共鉴定软体动物27种,隶属3纲11目16科22属。软体动物群落以亚热带种为主,共13种,其次为广温广布种和温带种,分别有12种和2种。春季生物量和栖息密度（156.15 g/m2,83.47个/m2）均高于秋季（88.04 g/m2,63.05个/m2）。春季优势种有疣荔枝螺、渔舟蜒螺、青蚶、齿纹蜒螺及隔贻贝等,而秋季有疣荔枝螺、单齿螺、青蚶、渔舟蜒螺、条纹隔贻贝及锈凹螺等,优势种春、秋季节变化明显。各采样点Shannon-Winner指数（H＇）值介于1.13~2.77,均值为1.85;Pielou均匀度指数（J＇）值介于0.33~0.77,均值为0.64;Margalef物种丰富度指数（D）值介于0.80~2.02,均值为1.27。运用Bray-Curtis相似性聚类和非度量多维标度（MDS）分析,发现春、秋季软体动物群落在地域空间上均可分为3个组,采用SIMPER分析发现组内各采样点间的平均相似率均高于37%,组间的平均相异率均高于66%。

In order to investigate the community structure characteristics of molluscs in the rock intertidal zone of Zhejiang,field sampling was carried out including eight rocky intertidal sections in Apr. and Oct.2009. A total of 27 species in two seasons were identified,belonging to 3 classes,11 orders,16 families and22 genera. The molluscs community in the intertidal zone of Zhejiang was mainly composed of subtropical species,including 13 species recorded,and followed by temperature widespread species and temperate species,with 12 species and 2 species,respectively,generally in accordance with the taxonomic features of the East China Sea. The average molluscs biomass and density in spring were 156. 15 g / m2and83. 47 ind. / m2,respectively; which were higher than those in autumn,being 88. 04 g /m2,63. 05 ind. /m2,respectively. Dominant species were Thais clavigera,Nerita albicilla,Barbatia obliquata,Nerita yoldii and Septifer bilocularis in spring; T. clavigera,Monodonta labio,B. obliquata,N. albicilla,Septifer virgatus and Chlorostoma rustica in autumn. Dominant species of molluscs varied with different seasons,indicating their functions in the community changed with seasons. The index of Shannon- Winner was from 1. 13 to 2. 77,the average being 1. 85. The index of Pielou＇s evenness was from 0. 33 to 0. 77,the average being 0. 64. The index of M argalef ＇s species richness was from 0. 80 to 2. 02,the average being1. 27. The community structure of molluscs had been studied by Bray-Curtis similarity clustering and non-metric multidimensional scaling（ M DS） analysis. The community could be spatially clustered into three groups during Spring ： the first was sections including Nanji Islands and Dongtou,the second was sections including Sanmen,Xiaowushitang,Xiangshan Bay,Ninghai and Xiushan,and the third was Shitang. However,autumn was also clustered into three groups,the first was sections including Sanmen,Xiaowushitang,Xiangshan Bay and Xiushan,the second was sections including Dongtou,Ninghai and Shitang,and the third was Nanji Islands.SIM PER analysis found that the average similarity rate between each section in the group was higher than37%,and the average difference rate between groups was higher than 66%.