山东半岛近岸海域蟹类群落结构特征的研究

根据2014年8月和10月、2015年2月和5月使用单船底拖网进行的4个航次调查数据,对山东半岛近岸海区的莱州湾及渤海南部、山东半岛北部和山东半岛南部等3个海域蟹类种类组成、时空分布、优势种、群落结构稳定性等群落结构特征进行了研究。结果显示,4次调查共捕获蟹类20种,隶属于10科17属,其中日本蟳（Charybdis japonica）和三疣梭子蟹（Portunus trituberculatus）是主要经济种类,其余均为小型饵料型蟹类;海区内主要的优势种为双斑蟳（Charybdis bimaculata）、日本蟳（Charybdis japonica）和三疣梭子蟹（Portunus trituberculatus）,3个海域优势种季节更替均十分明显;莱州湾及渤海南部和山东半岛南部2个海域生物量季节变化明显,春季较低,在夏季达到峰值,夏季到冬季呈降低趋势,山东半岛北部海域生物量季节变化不明显。3个海域蟹类群落物种多样性指数（H'）、丰富度指数（D）及均匀度指数（J'）均处于较低水平,并有一定的季节变化;水深、水温和盐度是影响蟹类群落结构的重要因子,渤莱沿岸流、黄海暖流和黄海冷水团通过影响海域内水温与盐度影响蟹类群落结构。研究表明山东半岛近岸海区蟹类以小型饵料型蟹类为主,蟹类多样性水平较低,优势种更替明显,群落季节更替指数较高,季节间迁移频繁,蟹类群落不稳定。

Study on the community structure of crabs in the coastal waters along Shandong Peninsula

Based on data from bottom trawl surveys in the coastal waters along the Shandong Peninsula from 2014 to 2015, the spatial and temporal distribution, structure community and dominant species of crabs were analyzed. Results showed that 20 kinds of crabs were captured during the four survey cruises, which belonged to 17 genera and 10 families. Portunus trituberculatus and Charybdis japonica were the main economic species and the others were low-value species. Charybdis immaculate, Charybdis japonica and Portunus trituberculatus were the main dominant species. The seasonal variation of the dominant species is obvious. Biomass in Laizhou Bay southern Bohai Sea and the coastal waters along the southern Shandong Peninsula changed seasonally with the highest in summer and the lowest in winter, but no significant seasonal change occurred in the coastal waters along northern Shandong Peninsula. According to the data, the average Shannon-Wiener diversity index (H''), Margalef richness index (D) and Pielou evenness index(J'') in survey waters were very low, which manifest that there was a lower-level diversity of crab in this waters. Result of CLUSTER analysis showed that water depth, water temperature and salinity were the main factors affecting the community structure. By influencing the water temperature and salinity, the Bohai-Lai Longshore Current, the Yellow Sea Warm Current and the Huanghai Sea Cold Water Mass influenced the community structure. This paper showed that most of crabs in the coastal waters along the Shandong Peninsula were small, bait-type species. The crab diversity was very low.The dominant species varied.The MI was very high. The results showed clearly that the crabs'' community structure were unstable.