[3] Based on genetic evidence, the population from the Indo-Pacific region is now recognized as a separate species, A. argus.

[2] The colour of the spotted sea hare is very variable, from pale gray to green, to dark brown.

They usually stay in relatively shallow water, but they have been found as deep as 40 m.[5] Minimum recorded depth is 0 m.[4] Maximum recorded depth is 3 m.[4] The right giant neuron of Aplysia dactylomela, which is found in the abdominal ganglion, is similar to that of vertebrates, meaning it is ideal for the study of electrophysiology, as well as conditioned-response studies.

It then pushes the water out from behind the animal by pressing the anterior parts of the parapodia together, thus forward motion is achieved.

The sea hare's usual mode of propulsion is crawling; it crawls by lifting the front end of the foot, stretching it forward then placing it on the ground in front, creating an arching pattern; the remainder of the body follows this arching pattern until the tail is reached.