Feeding ecology of detritivorous and carnivorous pelagic copepods

1.在上颌骨和上颌骨足上有特殊的感觉刚毛，属于食腐哲水蚤科Diaxidae、Phaennidae、Scolecitrichidae和Tharybidae的11个属。蠕虫状和刷状的感觉刚毛在这些类群中很常见。除了这两种感觉刚毛外，有些类群还有不同的感觉刚毛。这些感觉刚毛可能是化学感受器的基础上的精细结构。蠕虫状和刷状感觉刚毛在微管带的数量和构型上存在差异，这可能表明了不同的敏感性。肠道内容物分析显示，他们以碎屑为食，如apapturularian房屋和甲壳类动物尸体和/或蜕皮。头虱属有一对大的反射眼睛，专门吃甲壳类动物的碎片，这表明这些反射眼睛可能在检测碎屑中发挥作用。来自红海的九种Poecilostomatoid Oncaea经常以附肢房屋为食。2.肉食性的哲水蚤异杆鱼有一个中空的下颌腹面牙齿，有一个近端孔和一个基部开口。牙齿的远端区域是皮下注射的针状，并由蛋白石层加强。唇的后表面带有一对侧部的大腺体开口，其位置接近于近腹侧牙齿的基底部开口，并且看起来正好适合于该开口。毒液或麻醉剂从唇开口注入到下颌腹面牙齿的管状结构中，然后在捕获猎物大型动物（如具有粗壮上颌骨的桡足类和多毛类）后立即从其亚端孔释放到猎物中。支序分析推断，最先进的属，异杆属，半杆属和新杆属，在家庭的下颌骨和唇进行这些专门的结构。任何其他食肉类哲水蚤从未报道过使用这种专门的进食机制。

1. Eleven genera belonging to the detritivorous calanoid families Diaixidae, Phaennidae, Scolecitrichidae and Tharybidae have special sensory setae on the maxillae and maxillipeds. Worm-like and brush-like sensory setae are commonly found in these taxa. In addtition to these two sensory setae some taxa have different ones. These sensory setae are probably chemoreceptors based on the fine structures. Worm-like and brush-like sensory setae are different in the number and configuration of microtubule bands, which may indicate different sensitivity. Gut content analyzes revealed that they fed on detritus such as appendicularian houses and crustacean carcasses and/or exuviae. Cephalophanes spp. with a pair of large reflecting eyes exclusively fed on crustacean fragments, suggesting that these reflecting eyes may play roles in detection of detritus. Nine species of the poecilostomatoid Oncaea from Red Sea frequently fed on appendicularian house. 2. The carnivorous calanoid Heterorhabdus has a hollow mandibular ventralmost tooth with a subterminal pore and a basal opening. The distal region of the tooth is hypodermic needle-like and is strengthened by opal layrs. The posterior surface of the labrum carries a lateral pair of large gland openings, which are located close to, and appear to fit exactly the basal openings of the ventralmost teeth. Venom or anaesthetic is injected from the labral openings into the tubular structure of the mandibular ventralmost tooth, and then released into the prey from its subterminal pore immediately after capture of prey macrozooplankters such as copepodids and polychaetes with the stout maxillae. A cladistic analysis inferred that the most advanced genera, Heterorhabdus, Hemirhabdus and Neorhabdus, carry these specialized structures in the mandible and labrum in the family. Any other carnivorous calanoids have never been reported to employ such a specialized feeding mechanism.