The volumetric contributions made by prey and plant material to the diets of 4 elasmobranch and 14 teleost species, collected seasonally by trawling from waters along ca. 200 km of the lower west coast of Australia, have been compared. These benthic carnivores, which were all abundant and collectively contributed 83% to the total number of fish caught, represented nine families (Urolophidae, Scorpaenidae, Triglidae, Platycephalidae, Sillaginidae, Carangidae, Gerreidae, Mullidae and Pempherididae). Some species were numerous in both shallow (5-15 m) and deeper (20-35 m) waters and in both northern and southern regions, whereas others were largely confined to one of these water depths or regions. Comparisons between the diets of the different species, which utilised data collected from individuals throughout the study area, demonstrated that the dietary composition of any given species was almost invariably significantly different from that of every other species. This partly reflected the fact that, while errant polychaetes, gammarid amphipods and tanaids were ingested by all species, their contributions to the diets of the different species varied. Furthermore, echinoderms contributed to the diets of just nine species, and this was substantial only in the case of two sillaginid species, while teleosts were never consumed by six species and only made a marked contribution to the diets of the single species of platycephalid. The diet of each species underwent size-related changes, reflecting a shift from the consumption by smaller fish of prey such as amphipods, mysids and copepods, to the ingestion by larger fish of prey such as polychaetes, carid decapods, isopods and small teleosts. The interspecific and intraspecific differences in dietary compositions would spread the food resources amongst and within species, thereby reducing the potential for competition for those resources within the fish community. Non-metric multi-dimensional scaling (MDS) ordination plots emphasised that the dietary compositions of species within each family possessed some obvious similarities, reflecting similarities in body and mouth morphology and feeding behaviour. However, the extent to which the dietary compositions of the different families were similar or different was often not related to the phylogenetic relationships amongst those families. Furthermore, while differences in mouth size and morphology could sometimes be used to account for differences amongst the diets of the full suite of species, this was not always the case. Thus, the ways in which species feed and use their ancillary feeding structures were also employed to help elucidate the basis for variations in diets.

中文翻译：

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澳大利亚下西海岸海水中 18 种丰富的底栖肉食鱼类的食物资源分配

猎物和植物材料对 4 种 elasmobranch 和 14 种硬骨鱼的饮食做出的体积贡献，通过从大约 10 年的水域拖网捕捞季节性收集。澳大利亚下西海岸 200 公里，进行了比较。这些底栖食肉动物数量众多，合计占捕捞鱼类总数的 83%，代表九个科（Urolophidae、Scorpaenidae、Triglidae、Platycephalidae、Sillaginidae、Carangidae、Gerreidae、Mullidae 和 Pempherididae）。一些物种在浅水 (5-15 m) 和更深 (20-35 m) 水域以及北部和南部地区数量众多，而其他物种则主要限于这些水深或区域之一。不同物种的饮食之间的比较，利用从整个研究区域的个体收集的数据，证明任何给定物种的饮食组成几乎总是与其他所有物种的饮食组成显着不同。这在一定程度上反映了这样一个事实，即虽然所有物种都摄入了错误的多毛类动物、伽马科片脚类动物和 tanaids，但它们对不同物种饮食的贡献各不相同。此外，棘皮动物仅对 9 个物种的饮食做出了贡献，而这仅在两种 sillaginid 物种的情况下才显着，而硬骨鱼从未被 6 个物种食用，仅对单一物种的 platycephalid 的饮食做出了显着贡献。每个物种的饮食都经历了与大小相关的变化，反映了从较小的猎物（如片脚类、糠虾和桡足类）的消费转变为较大的猎物（如多毛类、棘足类、等足类动物和小型硬骨鱼。膳食成分的种间和种内差异会在物种之间和物种内传播食物资源，从而降低鱼类群落内对这些资源的竞争的可能性。非度量多维标度 (MDS) 排序图强调每个科内物种的饮食组成具有一些明显的相似性，反映了身体和口腔形态以及摄食行为的相似性。然而，不同科的膳食成分相似或不同的程度通常与这些科之间的系统发育关系无关。此外，虽然有时可以使用嘴巴大小和形态的差异来解释全套物种的饮食差异，情况并非总是如此。因此，物种进食和使用其辅助进食结构的方式也被用来帮助阐明饮食变化的基础。