Feeding habits and selectivity of the wide-eyed flounder, <i>Bothus podas</i> (Delaroche, 1809) (Bothidae) from the southern Tyrrhenian sea

In order to assess the diet composition of the wide-eyed flounder <i>Bothus podas</i>, we analysed the stomach contents of 388 specimens collected seasonally on sandy bottoms of the north-western coast of Sicily (central Mediterranean). The benthic communities in the same area were also studied in order to investigate the feeding selectivity of <i>B. podas</i>. The prey items found in the stomach contents analysed were mostly benthic organisms. The diet composition of <i>B. podas</i> was dominated by Gammaridea, Apseudidae and Cumacea that were also the most abundant categories in the benthic community. Active prey, such as benthic and epibenthic crustaceans, were highly selected, whereas molluscs and polychaetes were only occasionally ingested. Significant differences found in prey abundance by site were related to the different benthic compositions in the sites examined rather than to changes in the feeding behaviour of <i>B. podas</i>. Significant differences in diet by seasons were explained by the highest abundance of Caprellidea, Gammaridea and Cumacea in spring and summer. The observed feeding patterns were related to spatial and temporal variation of prey abundance in the benthos. As a result, <i>B. podas</i> can be considered an active opportunistic predator.

为评估大眼鲆（Bothus podas）的日粮组成，我们对采自地中海中部西西里岛西北海岸沙质底质区域的388尾经季节性采集的标本的胃容物进行了分析。同时针对该区域的底栖群落开展研究，以探究大眼鲆的摄食选择性。分析所得胃容物中的猎物类群以底栖生物为主。大眼鲆的日粮组成以钩虾亚目（Gammaridea）、异足虫科（Apseudidae）及涟虫目（Cumacea）占主导地位，这三类同时也是底栖群落中丰度最高的类群。主动活动的猎物，如底栖及底上甲壳类，被高度偏好摄取；而软体动物与多毛类则仅偶有被摄入。不同采样位点间猎物丰度的显著差异，与各考察位点的底栖群落组成差异相关，而非源于大眼鲆摄食行为的改变。不同季节的日粮组成差异，可归因于春季与夏季麦秆虫亚目（Caprellidea）、钩虾亚目及涟虫目丰度的显著提升。观测到的摄食模式与底栖生物群落猎物丰度的时空变化存在紧密关联。综上，大眼鲆可被归类为活跃的机会主义捕食者。