Chelidonura sandrana

Chelidonura sandrana is a species of sea slug, or "headshield slug", a marine opisthobranch gastropod mollusk in the family Aglajidae.

Distribution
This species lives from Tanzania to Australia.

Ecology
Chelidonura sandrana is a simultaneously hermaphroditic species. Contrary to classic theoretical predictions, Sprenger et al. (2011) have shown for the first time that the mating rate is largely unresponsive to variations in mate availability in this simultaneous hermaphrodite. With mating rates being close to the female fitness optimum, their findings challenge the prevailing notion of male-driven mating rates in simultaneous hermaphrodites, and call for complementary investigations of mating-rate effects on fitness through the male sexual function.