The genus Aplysia belongs to the family Aplysiidae and is a genus of sea hares. The general description of these sea hares can be found under the entry about the superfamily Aplysioidea (Sea hares)
- Aplysia brasiliana Rang, 1828 : Mottled Sea Hare, Sooty Sea Hare (possibly = Aplysia fasciata)
- Distribution : West-Atlantic (from New Yersey to Brazil, East-Atlantic, around Ghana)
- Length : up to 27 cm
- Color : variable
- Aplysia californica J.G. Cooper, 1863 : California Sea Hare, California Black Sea Hare
- Aplysia cedrocensis Bartsch & Rehder, 1939
- Aplysia cervina Dall and Simpson, 1901
- Aplysia dactylomela Rang, 1828 : Spotted Sea Hare
- Distribution : Cosmopolitan; tropical and temperate seas.
- Color : from pale gray to green to dark brown.
- Description : large black rings on the mantle; good swimmer
- Aplysia depilans Gmelin, 1791
- Distribution : Eastern Atlantic, Mediterranean.
- Description : thin, yellow inner shell
- Aplysia donca Ev. Marcus and Er. Marcus, 1960
- Distribution : North America, West-Atlantic
- Aplysia extraordinaria Allan, 1932 (possibly = Aplysia gigantea)
- Distribution : Western Australia, New Zealand.
- Length : more than 40 cm
- Aplysia fasciata Poiret, 1798 (possibly = Aplysia brasiliana).
- Distribution : East Atlantic, West Africa.
- Length : 40 cm
- Color : dark brown to black.
- Description : sometimes a red border to the parapodia and oral tentacles;
- Aplysia geographica . Adams and Reeve, 1850
- Aplysia gigantea
- Distribution : Western Australia.
- Length : 60 cm
- Color : dark brown to black
- Description : the skin secretions are very distasteful; washed up specimens; have been implicated in the deaths of dogs;
- Aplysia juliana Quoy & Gaimard, 1832 : Walking Sea Hare
- Distribution : cosmopolitan, in all warm seas.
- Color : various, from uniform to pale brown.
- Description : no purple gland, therefore no ink secretions; posterior end of the foot can act as a sucker.
- Aplysia kurodai Baba, 1937
- Distribution : NW Pacific.
- Length : 30 cm
- Color : dark brown to purplish black, dotted with white spots.
- Aplysia morio A. E. Verrill, 1901: Atlantic Black Sea Hare, Sooty Sea Hare
- Distribution : East Atlantic.
- Length : 40 cm
- Color: black to deep brown; no spots;
- Aplysia oculifera Adams & Reeve, 1850
- Distribution : Indian Ocean; West Pacific.
- Description : small brown eye-spots.
- Aplysia parvula Guilding in Moerch, 1863 : Pygmy Sea Hare
- Distribution : worldwide in warm to temperate seas.
- Length : 6 cm
- Color : brown to green spots.
- Aplysia punctata Cuvier, 1803 (possibly = Aplysia punctata)
- Distribution : NE Atlantic.
- Length : 20 cm
- Color : very variable
- Aplysia reticulopoda Beeman, 1960 : Net-foot Sea Hare
- Aplysia sagamiana Baba, 1949
- Distribution : East Australia, Japan;
- Aplysia sibogae Bergh, 1905 (probably = Aplysia juliana)
- Aplysia sydneyensis Sowerby, 1869
- Distribution : Australia.
- Length : 15 cm.
- Description : not clearly defined.
- Aplysia vaccaria Winkler, 1955 : California Black Sea hare (possibly = Aplysia cedrocensis)
- Distribution : Pacific Coast of California.
- Length : very big – up to 75 cm
- Color : black.
- Description : no purple ink; huge internal shell.
- Aplysia willcoxi Hellprin, 1886de:Aplysia
