在这项研究中,我们描述并比较了饮食,每月饲喂强度,以及在本格拉北部独特的栖息地捕获的西海岸Steenbras(Lithognathusaureti)和silverkob(Argyrosomusinodorus)的状况。调查了从2020年10月至2022年9月捕获的179个西海岸Steenbras和114个银质kob的胃含量。根据食物的供应情况,西海岸的Steenbras的摄食强度高峰在冬季和夏季似乎是机会主义的。鱼的状况,然而,在南方夏季产卵期的开始(10月)和结束(4月)达到顶峰,肝细胞指数(HSI)为1.5%,条件因子(CF)为0.022%。在西海岸Steenbras的饮食中发现了七个猎物类群(双壳类,骨鱼,其他软体动物,藻类,甲壳类动物,CNIDARIA,和polychaetas)和silverkob饮食中的六个类群(双壳类,甲壳类动物,骨鱼,藻类,海星,和浮游动物),表明这两个物种的通才摄食行为。双壳类动物是西海岸甜草饮食中最重要的猎物(相对重要性指数[IRI]为95.9%)。银鱼饮食中最重要的猎物是甲壳类动物(83.1%的IRI)和硬骨鱼(16.0%的IRI)。甲壳类动物在中小型银科的饮食中最重要,而硬骨鱼是最重要的饮食更大的银kob(>75厘米),不同大小类别的IRI%存在显著差异。Schoener的生态位重叠指数表明,西海岸的Steenbras和Silverkob之间的生态位重叠相对较低(0.11)。这使它们能够共存,因为它们的摄食习惯使它们能够在沿海礁石和沙质栖息地占据独特的生态位,并减少对资源的竞争。
In this study, we described and compared the diet, monthly feeding intensity, and condition of west coast steenbras (Lithognathus aureti) and silver kob (Argyrosomus inodorus) caught at a unique habitat in the northern Benguela. Stomach contents of 179 west coast steenbras and 114 silver kob caught from October 2020 to September 2022 were investigated. The peak in feeding intensity of west coast steenbras appeared to be opportunistic during winter and summer periods depending on food availability. The fish condition, however, peaked at the beginning (October) and at the end (April) of the austral summer spawning period, with the hepatosomatic index (HSI) at 1.5% and the condition factor (CF) at 0.022%. Seven prey taxa were found in the diet of west coast steenbras (bivalves, bony fishes, other mollusks, algae, crustaceans, cnidaria, and polychaetas) and six taxa in the diet of silver kob (bivalves, crustaceans, bony fishes, algae, starfish, and zooplankton), indicating generalist feeding behavior in both the species. The bivalves were the most important prey items in the diet of west coast steenbras (95.9% index of relative importance [IRI]). The most important prey items in the diet of silver kob were crustaceans (83.1% IRI) and bony fishes (16.0% IRI). Crustaceans were most important in the diet of small-to-medium-sized silver kob, whereas bony fishes were most important in the diet of larger silver kob (>75 cm), with significant differences of IRI% by size class. Schoener\'s index of niche overlap indicated a relatively low overall niche overlap (0.11) between west coast steenbras and silver kob. This allows them to coexist as their feeding habits allow them to occupy unique niches in the coastal reef and sandy habitat and reduce competition for resources.