Spotted Seahare

Overview

The spotted sea hare (Aplysia dactylomela) is a large, shell-less marine gastropod recognized by its distinctive pattern of black rings and blotches. Primarily found in the Atlantic Ocean and the Mediterranean Sea, this herbivorous sea slug is well-known for its nocturnal habits and unique defense mechanisms.

Distribution & habitat

This species inhabits shallow tropical and warm temperate waters, typically ranging from the intertidal zone to depths of about 40 meters. They are commonly found in rocky areas, seagrass beds, and environments with dense algal cover, where they graze on seaweed. While historically considered a cosmopolitan species, recent genetic research has restricted the true A. dactylomela to the Atlantic and Mediterranean regions, distinguishing it from the similar Indo-Pacific species, A. argus.

Appearance

Growing up to 40 cm in length, the spotted sea hare has a soft, smooth body that varies in color from pale yellow-green to dark brown, depending on its diet. Its most identifying feature is the network of irregular black rings and blotches covering its mantle and parapodia. Like other sea hares, it possesses two pairs of sensory tentacles on its head; the upper pair, known as rhinophores, resemble rabbit ears, giving the animal its common name. A small, vestigial, hatchet-shaped shell is hidden internally beneath the mantle.

Biology & behavior

Active primarily at night, these slugs spend their days resting in crevices or under rocks. They move by crawling along the substrate, though they are also capable of swimming by rhythmically undulating their large, wing-like parapodia. When threatened or handled, they can release a purple ink or a malodorous mucus to deter predators. As hermaphrodites, they often mate in chains, with individuals depositing long, tangled strings of eggs in various shades of yellow, green, or brown.