Photoreceptors of cubozoan jellyfish

摘要: The anatomically sophisticated visual system of the cubozoan jellyfish Carybdea marsupialis is described. Individual cubomedusae have eight complex eyes, each with a cornea, lens, and retina ciliated photoreceptor cells, slit ocelli, dimple ocelli. cells eyes are bipolar resemble vertebrate rod cells. Each has an outer cylindrical light-receptive segment that projects into vitreous space separates lens retina, inner rich in pigment granules, basal region housing nucleus. modified cilium 9 + 2 arrangement microtubules plus stacks membrane. These membrane form numerous discs oriented transversely to long axis cell. connected by slender stalk. end forms axon underlying layer interneurons. ocellus composed containing granules. Rhodopsin-like opsin-like proteins found segments photoreceptors eyes. An ultraviolet-sensing protein present regions some also detected cellular crystallin proteins, shows paucity organelles high concentration homogeneous cytoplasm. Neurons expressing RFamide (Arg-Phe-amide) comprise subset interneurons beneath retinas RFamide-positive fibers extend from these neurons stalks rhopalia, eventually entering subumbrellar nerve ring. Vision may play role navigation, feeding, reproduction cubomedusae.