Ommatophore (Eyestalk) Magic: Lobatus costatus

Abstract

The conch (Lobatus costatus) (Fig A; Image by Martin S. Gilman, MEd), a slow-moving, herbivorous bottom-dweller has a relatively large (up to 1.5 mm in diameter) and sophisticated eye compared with other gastropods. The stalks are modified tentacles and support olfactory and visual organs (Fig B). These stalks protrude from beneath the shell and move independently. The stalks will regenerate topographically correct eyes after injury or loss of the eyes. The stalked eye (Fig C) shows the olfactory organ (black arrow) and large spherical crystalline lens (green arrow).