Meeting Abstract
Unlike the mammalian retina, the teleost fish retina undergoes persistent neurogenesis from intrinsic stem cells. To understand retinal development in the unusual elopomorph superorder, retinal characteristics were analyzed over the course of development in three ecologically distinct elopomorph fishes—ladyfish (Elops saurus), bonefish (Albula vulpes), and speckled worm eel (Myrophis punctatus). Photoreceptor morphologies, distributions and spectral absorption were studied at larval, juvenile and adult stages. All pre-metamorphic elopomorph retinas are rod-dominated (unlike most teleost fish species), while later retinal characteristics closely correlated with post-metamorphic ecology. Adult E. saurus has high rod densities, grouped photoreceptors, a reflective tapetum, and longer-wavelength photopigments, supporting vision in turbid, low-light conditions. A. vulpes has higher cone densities, lower rod densities and shorter-wavelength photopigments, supporting diurnal vision in shallow, clear water. M. punctatus loses cones during metamorphosis, develops new cones after settlement, and maintains high rod but low cone densities, supporting primarily nocturnal vision. Thus, the retina changes in dramatic ways over the course of development, and these changes support ecology of each species and developmental stage.
