东海浮游翼足类(pteropods)种类组成和多样性研究

Species composition and diversity of pteropods in the East China Sea

根据 1997-2000年东海 23°30′-33°00′N、118°30′-128°00′E海域四季调查资料,运用定量、定性方法探讨了东海浮游翼足类种类组成、种类数、物种多样性指数(H′)及其与环境因子的关系。结果表明:四季中共出现翼足类 21种,其中尖笔帽螺 (Creseisacicula)、马蹄螔螺 (Limacinatrochiformis)、强卷螺 (Agadinasyimpsoni)、蝴蝶螺(Desmopteruspapilio)、锥笔帽螺(C. virgulavar. comica)、棒笔帽螺(C. clava)、玻杯螺(Hyalocylizstriata)、长吻龟螺(Cavolinialongirostris)、芽笔帽螺 (Creseisvirgula)和拟海若螺 (Paraclionelongicaudata)等 10种为常见种,胖螔螺(Limacinainflata)和皮鳃螺(Pneumodermaatlanticum)等两种为次常见种,其余 9种是稀有种。在春季转至夏季、冬季转至春季时,种类组成出现明显的季节更替现象;冬春季种类分布仅受温度变化的影响,而夏秋季则受温度和10m层或底层盐度变化的共同影响。在冬春季,东海近海由于暖流势力较弱,水温较低,翼足类种数较少,种类数和多样性指数南部大于北部,外海大于近海;从夏季到秋季随着台湾暖流势力的加强,海流将较多的种类带到东海北部和近海,尽管近海种数和多样性指数值仍呈南高北低的特征,但南部和北部,近海和外海的差距明显缩小。

Based on the data from four oceanographic censuses in the East China Sea (23°30′-33°00′ N, 118°30′-128°00′ E)during 1997-2000, and by means of qualitative and quantitative parameters, we analyzed the species composition, species number, and species diversity of pteropods and their relationships with environmental factors. A total of 21 pteropods species were observed in the East China Sea, of which Creseis acicula, Limacina trochiformis,Agadina syimpsoni, Desmopterus papilio, C. virgula var. comica, Cavolinia longirostris,Creseis virgula,C. clava,Hyalocyliz striata and Paraclione longicaudata were common species; Limacina inflata and Pneumoderma atlanticum were subordinate species; and the remaining 9 species were rare. According to seasonal alteration rates ( R ), obvious alternations of pteropods species occurred from spring to summer and from autumn to winter. The species number of pteropods peaked in autumn (20 species), followed by summer (15 species) and winter (14 species), and was lowest in spring (5 species). Results of regression analysis showed that the distribution of species number was affected only by water temperature in spring and winter, whereas it was dependent on water temperature, 10 m salinity and bottom salinity in summer and autumn. In winter and spring, because of low temperature and a nearshore weak warm current, species number was relatively low, and species diversity ( H′ ) was greater in the south or in nearshore areas than in the north or nearshore. From summer to autumn, though this trend still remained, the difference between nearshore and offshore areas was significantly reduced. This is because the Taiwan Warm Current brought more species to the nearshore region and the north part of the East China Sea.