Meeting Abstract
Conch are slow-moving, herbivorous, marine gastropods that possess prominent camera-type eyes at the ends of long, flexible stalks. Compared to the eyes of other gastropods, those of conch are large (up to 1.5 mm in diameter) and have sophisticated optics that include a lens with a graded refractive index. Conch also have a remarkable ability to regenerate eye tissue: after an eye is lost, a new eye will develop to take its place within weeks. Eye regeneration in conch appears to occur rapidly compared to eye regeneration in other gastropods. Despite our knowledge of the complexity and regenerative abilities of the eyes of conch, we know little about the visual responses of these animals either when their eyes are intact or while they are regenerating. Therefore, we measured rates of eye regrowth and tested how visual performance changes during the process of eye regeneration in the Florida fighting conch Strombus alatus. We found that rates of eye regrowth were greatest in S. alatus between 3-6 weeks following amputation but began to slow down thereafter. We also found that conch with two intact eyes respond consistently to the sudden appearances of objects with angular sizes of 23° or greater. When we amputated either one or both eyes from 24 conch and recorded the behavioral responses of these animals to visual stimuli once a week for twelve weeks, we found that animals with one amputated eye regained normal visual performance after five weeks whereas conch with two amputated eyes exhibited normal visual performance after seven weeks. Studying the restoration of visual performance during eye regeneration in conch may help us understand how a regenerating sensory system reconnects with an intact nervous system.
