Mating behavior in the pulmonate small melampus: can regeneration restore function?

Previous anatomical observations have established that the penial complex of adult Melampus bidentatus is specifically reinnervated and that the penial complex itself can regenerate. This review describes experiments to determine whether a reinnervated penial complex and a regenerated penial complex can function in mating. The snails are not self-fertile, so the ability to transfer sperm, evaluated by production of fertile eggs, was the test of successful regeneration. Snails with nerve transections produced fertile eggs within the time-span expected for axonal regeneration to the target organ. Penial complex ablation interfered with sperm transfer for two egg-laying cycles but fertile eggs were laid within a time-span consistent with regeneration of a penial complex.