东海北部大管鞭虾的食性

根据对2009年6月至2010年5月在东海北部采集到的720尾大管鞭虾胃含物的分析,对不同季节、性别、个体大小以及发育条件下大管鞭虾的摄食习性进行了研究.结果表明: 东海大管鞭虾的饵料生物共有43种(包含未鉴定种),甲壳类、有孔虫类和多毛类为其主要的摄食群类,在食物中所占的数量百分比分别为34.7%、29.4%和12.4%.大管鞭虾的饵料组成具有明显的季节波动,春季以有孔虫、藻类和无脊椎卵为主要食物;夏、秋季以有孔虫、鱼类和多毛类为主要食物;冬季则以多毛类和有孔虫类为主要食物.其摄食强度在春季和夏季较高,秋季较低.不同甲长的个体食性变化显著,小于24 mm的个体主食有孔虫类和藻类,24 mm以上的个体主食有多毛类和十足类;随着性腺发育雌性个体摄食等级呈现减弱的趋势,表明大管鞭虾摄食活动受到繁殖周期的影响.不同性别和不同季节大管鞭虾的食物重叠指数均较高,与栖息环境饵料资源的波动有关.大管鞭虾的营养级为2.67,属低级肉食性动物.

Feeding habits of Solenocera melantho in the northern East China Sea

The feeding habits of the mud shrimp Solenocera melantho were determined based on the analysis of 720 stomach contents sampled in the northern East China Sea during June 2009 and May 2010. The diet of the specimens was studied in relation to the season, sex, size class and reproductive condition. The diet of S. melantho consisted of 43 different prey categories, which belonged to small crustaceans, protozoa, polychaetes, algae, fishes and molluscs. Among these, crustaceans, foraminifera and polychaetes made up the main diet of S. melantho with 34.7%, 29.4% and 12.4% in abundance, respectively. Diet composition showed seasonal fluctuation and ontogenetic change. The predominant prey was foraminifera, algae and invertebrate eggs in spring, foraminifera, fishes and polychaetes in summer and autumn, and polychaetes and foraminifera in winter. The feeding intensity was high in spring and summer, and low in autumn. The small size group (<24 mm CL) tended to like foraminifera and algae, while the large size group (≥24 mm CL) preferred polychaetes and crustaceans. Females with advanced ovaries also displayed low stomach fullness, suggesting that feeding activity was affected by the reproductive cycle. S. melantho displayed a high food niche in both sexes and each season, which could be attributed to the fluctuations in available resources. The average trophic level of the S. melantho in four seasons was 2.67, indicating that the species in the northern East China Sea was of low-level carnivores.