Abstract—

This study focused on exploring the food utilization strategies and spring diets of four Oxynoemacheilus species inhabiting different river basins: O. anatolicus, O. eliasi, O. simavicus, and O. theophilii. Our goal was to fill the gaps in the knowledge of the feeding ecology of these small-bodied and non-commercial species, since surprisingly little is known of the properties of their ecological niche. The specimens of each species were collected by electrofishing from the tributaries of three different river basins (Burdur, Küçük Menderes, and Susurluk) in Türkiye. The vacuity index (%VI), represented by low values for each fish species (2.3–8.0), was a mark of high feeding density. Aquatic insects were the main food item in the spring diets of these four nemacheilid species, and they all exhibited generalist feeding habits. Because each species fed heavily on Diptera, niche breadth values (B_A) were low (0.01–0.08). Among these four species belonging to the same genus, feeding was closely related to river basin characteristics of the streams and different prey groups possible for different environments. Oxynoemacheilus simavicus and O. theophilii, sympatric species that inhabit the same stream, consumed similar food items in similar proportions, whereas O. anatolicus and O. eliasi, inhabiting different locations, gravitated towards other food types.

中文翻译：

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春季不同流域（西突厥）四种 Oxynoemacheilus 物种（Teleostei：Nemacheilidae）的营养生态位

摘要-

本研究重点探讨了栖息于不同流域的四种Oxynoemacheilus物种的食物利用策略和春季饮食： O. anatolicus、O. eliasi、O. simavicus和O. theophilii。我们的目标是填补这些小型和非商业物种的摄食生态学知识的空白，因为令人惊讶的是，人们对其生态位的特性知之甚少。每个物种的标本都是通过电捕鱼从土耳其三个不同河流流域（Burdur、Küçük Menderes 和 Susurluk）的支流中采集的。每种鱼类的真空指数（%VI）较低（2.3-8.0），是高饲养密度的标志。水生昆虫是这四种线虫春季饮食的主要食物，并且它们都表现出广泛的食性。由于每个物种都大量以双翅目为食，生态位宽度值 ( B _A）较低（0.01–0.08）。这四个同属物种的摄食与溪流的流域特征以及不同环境下可能存在的不同猎物类群密切相关。Oxynoemacheilus simavicus和O. theophilii是栖息在同一溪流的同域物种，以相似的比例消耗相似的食物，而O. anatolicus和O. eliasi栖息在不同的地点，倾向于其他食物类型。