heteropod

Heteropod refers to a group of oceanic gastropod mollusks belonging to the family Atlantidae. These are small, planktonic snails that live in the open ocean. A distinguishing feature of heteropods is their modified foot, which has evolved into a fin-like structure used for swimming. They are sometimes called "sea butterflies" due to their graceful, wing-like movements.

Heteropods are transparent or translucent, an adaptation that helps them camouflage in the open water, protecting them from predators. They are typically found in tropical and subtropical waters worldwide. Their diet consists mainly of other planktonic organisms, including other heteropods and small crustaceans.

Reproduction in heteropods can be complex, with some species being hermaphroditic, possessing both male and female reproductive organs. They are an important part of the oceanic food web, serving as prey for larger marine animals such as fish and sea turtles. The term "heteropod" itself means "different foot," referring to this unique adaptation.