Marine planktonic copepods frequently exhibit diel feeding cycles coupled with vertical migrations. However, copepod feeding rhythms can be influenced by factors others than different food availability between layers. In this study, we determined the changes in the diel feeding behaviour of two marine copepod species (Centropages typicus and Paracartia grani) through multigenerational laboratory rearing, ontogeny, and upon the exposure to predator chemical cues. The wild females of both C. typicus and P. grani showed marked feeding rhythms with higher ingestion rates at night. The diel rhythms of C. typicus were maintained in the first laboratory-reared generation (F1), suggesting maternal effects, but disappeared in the following generations. The P. grani females of a long-term culture (> 10 years) also showed no differences in their day–night feeding activity. Ontogenetic variations were detected in the F1 generation of C. typicus: feeding rhythms were absent in naupliar stages, but adults fed more intensely at night. In the case of the cultured P. grani, in general none of the stages showed feeding rhythms. Laboratory-reared C. typicus (8–11 generations) did not recover back the natural cyclic feeding when exposed to jellyfish and fish exudates, indicating that either predation risk does not significantly affect their diel feeding activity or predator-induced responses in marine copepods might not involve chemical signalling. Our study confirms that feeding-related functional traits of marine copepods can experience quick multigenerational changes in the laboratory; consequently, cultured copepods might not be good models for studies involving their diel feeding behaviour.

中文翻译：

---

多代饲养，个体发育和捕食威胁对co足类摄食节律的影响

海洋浮游co足类动物经常表现出迪尔（diel）进食周期以及垂直迁移。但是，co足类的摄食节律可能受不同因素的影响，而不是各层之间的食物供应量不同。在这项研究中，我们通过多代实验室饲养，个体发育以及暴露于捕食者化学线索，确定了两种海洋co足类物种（Centropages typicus和Paracartia grani）的迪尔摄食行为的变化。C. typicus和P. grani的野生雌性在夜间都有明显的摄食节律，摄食率较高。的昼夜节律C. typicus第一代实验室饲养（F1）的婴儿被保留下来，表明具有母性效应，但在随后的几代中消失了。长期培养（> 10年）的P. grani雌性在昼夜摄食活动上也没有差异。在F1一代的C. typicus中检测到了个体发育的变异：无节幼体阶段没有进食节奏，但成年人夜间进食更为剧烈。就培养的P. grani而言，通常所有阶段都没有表现出摄食节律。实验室饲养的C. typicus（8-11代）暴露于水母和鱼类渗出物后没有恢复自然的周期性觅食，这表明捕食风险不会显着影响其di食活动或捕食者在海洋co足类动物中引起的反应可能不涉及化学信号。我们的研究证实，海洋co足类动物的摄食相关功能性状可以在实验室中经历快速的多代变化。因此，培养的co足类可能不是研究其di食行为的好模型。