CSIR-National Institute of Oceanography, Dona Paula, Goa, 403004, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
Environ Sci Pollut Res Int. 2024 Feb;31(6):9183-9196. doi: 10.1007/s11356-023-31749-1. Epub 2024 Jan 8.
Benthic predatory catfishes are voracious and opportunistic predators and can easily shift their diet according to the availability of prey. In this study, feeding ecology of catfishes from two adjacent habitats of an estuarine bay is compared. The lower bay was relatively pristine as compared to the upper bay and was represented by two families of catfishes-Plotosidae and Ariidae, while the upper bay represented only ariid catfishes. Gut content analysis revealed that catfish predators from lower bay consumed conventional prey like teleosts and benthic invertebrates with a linear pattern of ontogenetic dietary shift. Plicofollis dussumieri and Plotosus canius occupied the position of top predators in the lower bay and were specialized feeders. Other predators like Plotosus lineatus, Arius arius, Arius jella, and Arius maculatus were generalist feeders occupying the position of mesopredators. However, in the upper bay, the catfish predators represented by Arius maculatus, Arius jella, and Arius arius predominantly fed on human discarded food. The easily available human food in the form of chicken, corn, and rice as noted from the investigated guts shows altered trophic guilds of ariid catfishes wherein only mid to large-sized catfish community was noted in this bay. A distinct "trophic switch" altered the trophic function from predation to scavenging which was observed in their feeding behavior. The anthropogenic impact in the form of unmanaged organic waste alters the role of predatory catfishes thereby restructuring the food web that may lead to unknown changes in the estuarine benthic ecosystems resulting in reduced ecosystem services.
底栖肉食性鲶鱼是贪婪且机会主义的捕食者，可以根据猎物的可获得性轻松改变其饮食。本研究比较了河口湾两个相邻栖息地的鲶鱼的摄食生态学。与上湾相比，下湾相对原始，代表了两个鲶鱼科-Plotosidae 和 Ariidae，而上湾仅代表了 ariid 鲶鱼。肠道内容物分析表明，来自下湾的鲶鱼捕食者以鱼类和底栖无脊椎动物等常规猎物为食，其摄食的种间变化具有线性模式。Plicofollis dussumieri 和 Plotosus canius 在下湾中占据顶级捕食者的位置，是专门的食者。其他捕食者如 Plotosus lineatus、Arius arius、Arius jella 和 Arius maculatus 是占据中上层捕食者位置的杂食者。然而，在上湾，以 Arius maculatus、Arius jella 和 Arius arius 为代表的鲶鱼捕食者主要以人类丢弃的食物为食。从调查的肠道中可以看出，人类丢弃的食物（如鸡肉、玉米和大米）是容易获得的，这表明 ariid 鲶鱼的营养群发生了改变，在上湾中仅注意到了中到大型鲶鱼群落。明显的“营养转换”改变了从捕食到食腐的营养功能，这在它们的摄食行为中可以观察到。以未管理的有机废物形式出现的人为影响改变了掠食性鲶鱼的作用，从而重构了食物网，这可能导致河口底栖生态系统发生未知变化，从而减少生态系统服务。
