This study aimed to evaluate whether polarized light or water turbidity enhances Octopus americanus paralarvae daily feeding rates (FRs) when fed on natural prey (Acartia lilljeborgi copepods) and estimate their daily energy consumption. Paralarva individual FR was obtained using a density of 80 copepods L⁻¹. The polarized light experiment had a control (regular light) and two polarized light treatments (electronic vectors at 90° and 45°) for newly-hatched and 15-day-old paralarvae. The water turbidity experiment had a control (0.09 NTU [nephelometric turbidity unit]), and three other treatments (3.80, 19.44, and 45.82 NTU) obtained with different Isochrysis galbana densities for newly-hatched and 8-day-old paralarvae. Five experimental units were used for each treatment and the experiments lasted 24 hr. No significant differences in the FRs were found for polarized light and water turbidity. The general FR was 3.9 ± 2.3, 7.7 ± 2.9, and 15.9 ± 6.5 copepods paralarva⁻¹ day⁻¹ for newly-hatched, 8-day-old, and 15-day-old paralarvae, respectively. Water turbidity at the higher NTU might have impacted swimming performance of paralarvae, reducing their FRs. Our methodological errors for quantifying FRs of paralarvae were <3%, providing reliable results for understanding the daily feeding requirements of Octopus paralarvae under rearing conditions and their feeding ecology in the wild.

中文翻译：

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将偏振光和水浊度与美洲章鱼副幼虫的摄食率联系起来

本研究旨在评估以天然猎物（ Acartia lilljeborgi桡足类动物）为食时，偏振光或水浊度是否会提高美洲章鱼副幼虫的每日摄食率（FRs），并估计它们的每日能量消耗。^{使用 80 个桡足类 L -1}的密度获得了 Paralarva 个体 FR 。偏振光实验对新孵化的和 15 天龄的旁幼虫进行了对照（常规光）和两种偏振光处理（90° 和 45° 的电子矢量）。水浊度实验有一个对照（0.09 NTU [比浊法浊度单位]）和用不同等鞭金藻获得的其他三个处理（3.80、19.44 和 45.82 NTU）新孵化和 8 日龄旁幼虫的密度。每次处理使用五个实验单元，实验持续 24 小时。偏振光和水浊度的 FR 没有显着差异。新孵化、8 日龄和 15 日龄旁幼虫的一般 FR 分别为 3.9 ± 2.3、7.7 ± 2.9 和 15.9 ± 6.5 桡足类副幼虫^-1 天^{-1 。}较高 NTU 的水浊度可能会影响副幼虫的游泳性能，从而降低它们的 FR。我们量化副幼虫FRs的方法误差<3%，为了解章鱼副幼虫在饲养条件下的日常摄食需求及其在野外的摄食生态学提供了可靠的结果。