Institute of Marine Sciences and Management, Istanbul University, Istanbul, Turkey.
J Fish Biol. 2022 Sep;101(3):560-572. doi: 10.1111/jfb.15123. Epub 2022 Jul 11.
Trophic ecology studies on predator-prey interactions reveal insights into ecological communities and help understand a species' role in the food web by contributing to improved fisheries management and conservation capabilities. Understanding the ecological role of overexploited and endangered predators is essential to deciphering how their feeding behaviour influences food web dynamics. In this study, the authors investigated the feeding behaviour of the common and IUCN-listed Near Threatened (NT) thornback ray Raja clavata, using carbon and nitrogen stable isotope and stomach content analysis (SCA). It has recently suffered an 87% decline in reported catches from the Sea of Marmara within the last decade. These results show that thornback ray mainly feeds on teleost species, except in summer, with both methods showing this species changes its diet ontogenetically by SCA. This ontogenetic diet shift was at lengths 40-50 cm by changing group preferences from Crustacea to Teleostei. MixSIAR results showed that both adult and juvenile individuals of R. clavata feed mainly on the crustaceans, but the contribution of teleosts represented by Trachurus sp. was very low (<15%). The trophic position increased total length and was higher than other batoid species in the Sea of Marmara.
摄食生态研究揭示了捕食者-猎物相互作用对生态群落的深入了解，并通过提高渔业管理和保护能力，有助于理解物种在食物网中的作用。了解过度捕捞和濒危捕食者的生态角色对于解释它们的摄食行为如何影响食物网动态至关重要。在这项研究中，作者使用碳和氮稳定同位素和胃内容物分析（SCA）研究了常见的和列入 IUCN 濒危（NT）名单的近危（NT）刺鳐 Raja clavata 的摄食行为。在过去的十年中，该物种在马尔马拉海的报告捕捞量下降了 87%。这些结果表明，刺鳐主要以硬骨鱼类为食，除了在夏季，两种方法都表明该物种通过 SCA 发生了营养变化。这种营养变化的摄食习性发生在 40-50 厘米的长度上，通过改变对甲壳类动物的偏好，从甲壳类动物转变为硬骨鱼类。MixSIAR 结果表明，R. clavata 的成鱼和幼鱼主要以甲壳类动物为食，但以 Trachurus sp. 为代表的硬骨鱼类的贡献非常低（<15%）。营养位置随着总长度的增加而增加，并且高于马尔马拉海中的其他鳐鱼物种。
