As a prolific invasive species, Blue Catfish Ictalurus furcatus threaten native organisms in numerous estuarine and tidal freshwaters along the Atlantic coast of the United States. However, no published estimates of consumption rates are available for Blue Catfish in the scientific literature. This information is critical for development of bioenergetics models or estimation of population-level impacts on native species. Using a combination of field and laboratory studies, we provide the first estimates of daily ration, maximum daily ration, and consumption to biomass ratios for Blue Catfish populations. Ad libitum feeding trials conducted in our laboratory reveal that maximum daily ration in Blue Catfish varies by prey type, temperature, and fish size, with maximal feeding occurring in medium-sized Blue Catfish (500–600 mm total length) and at temperatures ≥15°C. Furthermore, estimates of daily ration were higher for fish prey (Gizzard Shad Dorosoma cepedianum) than for crustacean prey (blue crab Callinectes sapidus). Diel feeding chronologies based on field-collected diet samples from 1,226 Blue Catfish demonstrated river-specific variability in daily ration and maximum daily ration. Blue Catfish daily ration ranged between 2.27% and 5.22% bodyweight per 24 h, while maximum daily ration ranges between 8.56% and 9.37% bodyweight per 24 h. Estimates of consumption to biomass ratios varied by river and Blue Catfish size groupings but range between 2.42 and 3.39, which is similar to other benthic omnivores. This research will inform the assessment of predatory impacts of invasive Blue Catfish in the Chesapeake Bay and beyond as it will enable researchers to estimate predatory impacts through the coupling of population models, food habit information, and consumption rate information (current study).

中文翻译：

---

入侵蓝鲶鱼的食物消耗率估计

作为一种多产的入侵物种，蓝鲶鱼Ictalurus furcatus威胁着美国大西洋沿岸众多河口和潮汐淡水中的本地生物。然而，科学文献中没有公布的蓝鲶鱼消耗率估计值。此信息对于开发生物能量学模型或估计种群水平对本地物种的影响至关重要。结合实地和实验室研究，我们提供了蓝鲶鱼种群的每日定量、最大每日定量和消耗量与生物量比率的初步估计值。在我们实验室进行的随意采食试验表明，蓝鲶的最大日食量因猎物类型、温度和鱼的大小而异，最大摄食发生在中型蓝鲶（总长度 500-600 毫米）和温度≥15 ℃。此外，Dorosoma cepedianum）比甲壳类猎物（蓝蟹Callinectes sapidus））。基于现场收集的 1,226 条蓝鲶鱼的饮食样本的日粮喂养年表显示了每日定量和最大每日定量的河流特定变异性。蓝鲶日粮在每 24 小时体重的 2.27% 至 5.22% 之间，而最大日粮在每 24 小时体重的 8.56% 至 9.37% 之间。消耗量与生物量比率的估计值因河流和蓝鲶鱼大小分组而异，但范围在 2.42 和 3.39 之间，这与其他底栖杂食动物相似。这项研究将为评估切萨皮克湾及其他地区的入侵蓝鲶鱼的掠食性影响提供信息，因为它将使研究人员能够通过结合种群模型、饮食习惯信息和消费率信息来估计掠食性影响（当前研究）。