马鞍列岛海洋牧场褐菖鲉的摄食习性

海洋牧场是近岸渔业资源保护和恢复的有效途径,为评估海洋牧场建设对岩礁性鱼类的影响,本文基于马鞍列岛海洋牧场建设前后资源调查数据,利用胃含物分析和稳定同位素测试,研究了褐菖鲉的摄食习性.结果表明:海洋牧场建设前褐菖鲉主要摄食端足类、蟹类和头足类,优势饵料生物种类为麦秆虫、日本枪乌贼、日本蟳、日本岩瓷蟹和滩栖阳遂足等.随体长的增大,蟹类的比例增加,而端足类的比例减少.洋牧场建设后褐菖鲉主要摄食蟹类、端足类和鱼类,优势饵料生物种类为双斑蟳、日本蟳、麦秆虫和赤鼻棱鳀等.随体长的增大,鱼类和蟹类的比例增加,而端足类的比例先增加后减少.根据稳定同位素分析结果,海洋牧场区褐菖鲉可以划分为体长<10.0 cm、10.0～13.9.0 cm和≥14.0 cm 3个摄食群体,平均营养级为3.40级.

Feeding habits of the marbled rockfish Sebastiscus marmoratus in the marine ranching off Ma’an Archipelago,China

Marine ranching is considered as an efficient tool to protect and restore the coastal fishe-ries resource. In order to assess the ecological impacts of the construction of marine ranching on rocky fishes, the feeding habits of Sebastiscus marmoratus collected at the marine ranching area off Ma’an Archipelago were studied using stomach contents analyses and stable isotope analyses. Results showed that S. marmoratus mainly preyed on amphipoda, crabs and cephalopods before the construction of marine ranching. The dominant prey species were Caprella sp., Loligo japonica, Charybdis japonica, Petrolisthes japonicas and Amphiura vadicola. Proportion of crabs in the diet of S. marmoratus increased with the increase of fish size, whereas the proportion of amphipoda decreased. After the construction of marine ranching, S. marmoratus fed mainly on crabs, amphipoda, and fishes. The dominant prey species were C. bimaculata, C. japonica, Caprella sp. and Thryssa kammalensis. Proportions of fishes and crabs in the diet of S. marmoratus increased with the increase of fish size, whereas the proportion of amphipoda increased and then decreased. Results of the stable isotope analyses suggested that S. marmoratus populations in the marine ranching area off Ma’an Archipelago could be divided into three feeding groups based on size variations: <10.0 cm BL, 10.0-14.0 cm BL, and ≥14.0 cm BL. The mean trophic level of S. marmoratus was estimated as 3.40.