关键词: coastal flatfishes stable isotopes stomach contents sympatric trophic ecology

Mesh : Animals Flatfishes / physiology Ecology Nutritional Status Food Chain Isotopes / analysis Flounder

来  源:   DOI:10.1111/jfb.15458

Abstract:
Sympatric flatfish predators may partition their resources in coastal environments to reduce competition and maximise foraging efficiency. However, the degree of spatial and temporal consistency in their trophic ecology is not well understood because dietary studies tend to overlook the heterogeneity of consumed prey. Increasing the spatial and temporal scale of dietary analyses can thus help to resolve predator resource use. We applied a stomach content and multi-tissue (liver and muscle) stable isotope (δ13 C, δ15 N and δ34 S) approach to investigate the feeding habits of two co-occurring flatfish predators, common dab (Limanda limanda) and European plaice (Pleuronectes platessa), across four bays on the Northumberland coast (UK) over short (hours), medium (days) and long (months) temporal scales. Stomach content analyses showed spatial consistencies in predator resource use, whereas stable isotope mixing models revealed considerable inter-bay diet variability. Stomach contents also indicated high dietary overlap between L. limanda and P. platessa, while the stable isotope data yielded low to moderate levels of overlap, with cases of complete niche separation. Furthermore, individual specialisation metrics indicated consistently low levels of specialisation among conspecifics over time. We document changes in resource partitioning in space and time, reflecting diet switching in response to local and temporal fluctuations of patchily distributed prey. This study highlights how trophic tracers integrated at multiple temporal and spatial scales (within tens of kilometres) provide a more integrative approach for assessing the trophic ecology of sympatric predators in dynamic environments.
摘要:
同胞比目鱼捕食者可能会在沿海环境中分配资源,以减少竞争并最大程度地提高觅食效率。然而,由于饮食研究倾向于忽略食用猎物的异质性,因此营养生态的时空一致性程度尚未得到很好的理解。因此,增加饮食分析的时空尺度可以帮助解决捕食者资源的使用问题。我们应用了胃内容物和多组织(肝脏和肌肉)稳定同位素(δ13C,δ15N和δ34S)的方法来研究两种同时发生的比目鱼捕食者的摄食习惯,普通dab(Limandalimanda)和欧洲plaice(Pleuronectesplatessa),在诺森伯兰郡海岸(英国)的四个海湾上,中(天),和长(月)的时间尺度。胃含量分析显示捕食者资源使用的空间一致性,而稳定的同位素混合模型显示出相当大的海湾间饮食变异性。胃含量也表明利曼达乳杆菌和普氏疟原虫之间有较高的饮食重叠,虽然稳定的同位素数据产生了低至中等水平的重叠,具有完全生态位分离的情况。此外,个人专业化指标表明,在特定加班中,专业化水平始终较低。我们记录了资源分区在空间和时间上的变化,反映了饮食变化,以响应散乱分布的猎物的局部和时间波动。这项研究强调了营养示踪剂如何在多个时间和空间尺度(在数十公里内)整合,为评估动态环境中同胞捕食者的营养生态提供了一种更综合的方法。本文受版权保护。保留所有权利。
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