It lives in warm waters in the Caribbean Sea and off the south and southeastern coast of the United States, where it feeds on seaweed.

The shell is a fragile disc, hidden within the mantle, and the foot has large flaps at the side called parapodia which are used for swimming.

Its range includes the eastern coast of the United States, Bermuda, the West Indies, Florida, the Caribbean Sea, the Gulf of Mexico and Venezuela.

As the penis of one individual is inserted into the genital opening of another, chains or clusters of mating sea hares can form.

Fertilized eggs hatch and develop into veliger larvae, which drift with the plankton for at least a month and settle onto Laurencia seaweed.