胶州湾水母类生态的初步研究Ⅰ.群落结构及其年季变化

ECOLOGY OF JELLYFISHES IN JIAOZHOU BAY Ⅰ. SEASONAL AND ANNUAL CHANGES IN COMMUNITY STRUCTURE

近年来,有许多研究表明,水母类在某些近岸海域或半封闭型海湾,如美国的Narragansett湾和Cheseapeake湾,加拿大的新斯科舍省沿岸和Kulleet湾,德国的Kiel湾等,是影响浮游动物种群数量和鱼类补充量的重要因子(Denson,1982;Matsakis,et al.,1991;Purcell,et al.,1990,1994;Schneider,et al.,1998)。由于以上海域食物丰富,海流对水母类的驱散作用较小,而且为水螅体提供了底栖生活的附着条件,因此。

This paper reports results of the authors’ study on community structure, seasonal and annual variations of jellyfishes in Jiaozhou Bay based on 1980 to 1998 investigations data. So far totally 62 species were found, among which 14 species were first recorded in Jiaozhou Bay. Of the 62 species, 56 belong to Hydromedusea, 4 Syphomedusea, and 2 Ctenophora. Most of these Medusea and Ctenophores are low salinity and wide temperature types, a few are high salinity and high temperature types. The dominant species was Obelia in spring were Phialidium , Eirene, Muggiaea at-lantica, and Zanclea costata etc. In summer. Jellyfishes could seldom be collected in winter. The species abundance of jellyfish in Jiaozhou Bay was usually highest in June and July and quite high in autumn, but low in winter and spring. Analysis of annual variations showed that jellyfish species abundance decreased dramatically from 80s to 90s.