Feeding habits of juvenile Trematomus newnesi (Pisces, Nototheniidae) at Potter Cove, South Shetland Islands, Antarctica
Feeding habits of juvenile Trematomus newnesi (Pisces, Nototheniidae) at Potter Cove, South Shetland Islands, Antarctica
复制标题
南极洲南设得兰群岛波特湾的纽氏吸虫（Trematomus newnesi）幼鱼（双鱼座，Nototheniidae）的摄食习性
作者：
E. Barrera;G. L. Piacentino
采用出现频率 (F%) 和膳食系数 Q (%) 方法，对 2004-2005 年和 2005-2006 年夏季在南设得兰群岛波特湾拖网捕捞的纽氏吸虫幼鱼的膳食成分进行了分析。这些样本仅由 4-15.4 厘米（总长度）范围内的未成熟样本组成，与来自同一地点的较大鱼类（包括成鱼）的样本互补，这些样本在之前的工作中进行了分析。底栖底栖生物，如伽马里安片脚类和弓形桡足类，是主要（系数 Q）和最常见（F%）的猎物。在个体发育过程中，较小和较大的主要猎物的重要性分别减弱和增加。远洋磷虾在中小型鱼类的饮食中可以忽略不计，成为次要食物，但仅限于大于 12 厘米的鱼类。其他分类群很少出现并且偶尔构成食物。它们大多是底栖动物，如腹足类、双壳类、等足类、角足类和藻类，但少数中上层介形类和桡足类除外。与纽尼斯幼鱼后期幼鱼-成鱼阶段的中上层/浮游食性生活模式（包括冷冻鱼）不同，目前的结果表明，早期幼鱼仍然受到大型藻类床的庇护，捕食相关的底层底栖生物群落。
The dietary composition of juvenile Trematomus newnesi, trawled at Potter Cove, South Shetland Islands, in the summers 2004–2005 and 2005–2006 was analysed using frequency of occurrence (F%) and dietary coefficient Q (%) methods. The samples consisted exclusively of immature specimens in the range 4–15.4 cm (total length) and are complementary to those of larger fish from the same site, including adults, which were analysed in previous work. Benthic-demersal organisms such as gammaridean amphipods and harpacticoid copepods were the main (coefficient Q) and most frequent (F%) prey. The importance of the smaller and larger main prey diminished and increased, respectively, during ontogeny. Pelagic krill, being negligible in the diet of the small and medium size fish categories, became secondary food, but only for fish larger than 12 cm. Other taxonomic groups occurred scarcely and constituted occasional food. They were mostly benthic, such as gastropods, bivalves, isopods, cumaceans, and algae, with the exception of an insignificant number of pelagic ostracods and calanoid copepods. Unlike the more pelagic/planktivorous mode of life known for late juvenile-adult stages of T. newnesi, including cryopelagy, present results indicate that early juvenile fish remain sheltered among macroalgae beds preying on the associated community of demersal-benthic organisms.