【摘要】 于2013—2014年间在海坛岛长江澳沙滩采样,对小型底栖动物的类群组成、丰度及分布,自由生活海洋线虫(简称海洋线虫)群落的优势属、摄食类型、年龄结构及性比、物种多样性等方面进行研究。结果表明:小型底栖动物年平均丰度为(810.87±696.75)个/10 cm~2。在鉴定出的16个类群中,海洋线虫的丰度占小型底栖动物总丰度的52.36%,其次为腹毛虫,占21.14%。海洋线虫的年平均丰度为(424.54±400.23)个/10 cm~2,季节变化总趋势为夏季((783.45±336.45)个/10 cm~2)>春季((600.67±309.42)个/10 cm~2)>秋季((298.26±424.57)个/10 cm~2)>冬季((113.05±95.79)个/10 cm~2)。4个季度共鉴定出海洋线虫105种或分类实体,隶属于75个属,26个科。4个季度数量百分比超过5%的优势海洋线虫属有10个,分别是Axonolaimus、Theristus、Metachromadora、Mesacanthion、Rhynchonema、Epacanthion、Microlaimus、Viscosia、Lauratonema和Enoploides,不同季度的优势属存在差异。CLUSTER聚类表明,春、夏、秋季各潮带海洋线虫群落较为相似,与冬季差异较大。海洋线虫4种摄食类型年平均丰度百分比由高到低的顺序是1B (32.19%)> 2A (31.32%)> 2B (31.12%)> 1A (5.37%);春夏季以2A和1B为主导,秋冬季以2B和1B为主导。海洋线虫群落的物种多样性最高值出现在秋季(d=8.45,H′=3.36),最低在冬季(d=7.36,H′=2.92),春季与夏季的多样性相当;周年幼体的数量所占比例为45.47%,成体中雌雄个体比例为1.10∶1。更多还原

【Abstract】 The main island of Pingtan Comprehensive Pilot Zone, Haitan Island, which is the zone nearest to Taiwan Province, is the fifth largest island in China and the largest island in Fujian Province. With the development and increase in the urbanization of Pingtan, the beach tourism industry has developed rapidly. However, the beach is a simple and sensitive ecosystem, and the development of beach tourism would affect the assemblages and distribution of benthos, which would affect the structure and function of the sandy beach ecosystem. It is necessary to study the biological baseline and establish basic data for the evaluation of the ecosystem in Haitan Island. Meiofauna is one of the most important indicators of marine environmental quality owing to its ecological characteristics, such as high abundance and short life cycle. In order to study the groups, abundance, and distribution of meiofauna, feeding types and species diversity, age structure and sex ratio of marine nematodes, meiofaunal samples were collected from the sandy beach of Changjiangao, Haitan Island in Fujian Province in 2013 and 2014. The results showed that the mean annual abundance of meiofauna was(810.87±696.75) ind/10 cm~2, consisting of 16 meiofaunal assemblages. Nematoda was the most dominant group, accounting for 52.36%, followed by Gastrotricha, which constituted 21.14%. The mean annual abundance of nematodes was(424.54±400.23) ind/10 cm~2, the abundance varied seasonally as follows: summer((783.45±336.45) ind/10 cm~2) > spring((600.67±309.42) ind/10 cm~2) > autumn((298.26±424.57) ind/10 cm~2) > winter((113.05±95.79) ind/10 cm~2). A total of 105 species of nematodes were identified in the four seasons, belonging to 75 genera and 26 families. There were 10 genera of nematodes with dominance greater than 5% in the four seasons—Axonolaimus, Theristus, Metachromadora, Mesacanthion, Rhynchonema, Epacanthion, Microlaimus, Viscosia, Lauratonema, and Enoploides, but the dominant genera varied seasonally. Hierarchical cluster analysis showed that the nematode communities in spring, summer, and autumn shared greater similarity than those in winter. The percentage of the mean annual abundance of feeding types were 1 B(32.19%) > 2 A(31.32%) > 2 B(31.12%) > 1 A(5.37%), among which 2 A and 1 B were dominant in spring and summer, whereas 2 B and 1 B were dominant in autumn and winter. The number of nematode genera in autumn was the largest, whereas that in winter was the lowest. Nematode diversity was the highest in autumn(d=8.45, H′=3.36) and the lowest in winter(d=7.36,H′=2.92), and the diversity in spring and in summer was similar. The age structure of the nematodes revealed that the proportion of juveniles accounted by 45.47%, and the sex ratio(female?male) was 1.10∶1.更多还原