Blunt End Sea Hare, Dolabella auricularia
Blunt End Sea Hare, Dolabella auricularia. Sea Hare collected at Km 17, El Tule, Baja California Sur, photographed and returned to its native environment unharmed. Length: 18 cm (7.1 inches).
Blunt End Sea Hare, Dolabella auricularia. Sea Hare provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, August 2009. Size: 7.5 cm (3.0 inches).
Blunt End Sea Hare, Dolabella auricularia. Sea Hare collected off the beach at Cabo Real, Km 21, Baja California Sur, photographed and returned to its native environment unharmed. Length: 18 cm (7.1 inches).
Phylogeny: The Blunt End Sea Hare, Dolabella auricularia (Lightfoot 1786), is a member of the Aplysiidae Family of Sea Hares. The genus Dolabella is one of ten genera in this family, and there are three species in this genus. This species is also known as the Wedge Sea Hare, the Shoulderblade Sea Cat, and in Mexico as Liebre de Mar Chata. The name Dolabella comes from the Latin word meaning “small pickax” or “small hatchet”, and possibly refers to the profile shape of these animals. The species name auricularia comes from the Latin word meaning “ear-shaped”, and refers to the shape of the inner shell (vestigal).
Morphology: They have triangular shaped bodies with highly truncated posterior end. There is a large exhalant siphon in the middle of the back and a smaller inhalant siphon in front of the shield. The body may be smooth or covered with tubercules or skin flaps. Buried within the body is a large flattened heavily calcified shell called a vestigal. Blunt End Sea Hares vary in color. All are mottled shades of green, reddish, and brown that afford them strong camouflage in their habitat. When disturbed, they can release a reddish-purple ink. They reach a maximum of 20 cm (7.9 inches) in length.
Habitat and Distribution: The Blunt End Sea Hare is found in sheltered bays and lagoons. They live on sand and mud substrates and are often associated with sea grass beds. They are also found in large intertidal rocky pools. They live in the intertidal zone, and to depths of 15 m (50 feet). Blunt End Sea Hares are found worldwide in tropical seas. They can be found in all Mexican Waters south of the 25th parallel latitude. Fossil records indicate that they date back to the Early Miocene Epoch.
Reproduction: Blunt End Sea Hares are hermaphrodites, possessing both male and female reproductive organs. Reproduction is sexual with internal fertilization. When mating, they usually form chains of several individuals, functioning as both male or females. The eggs are laid as a stringy mass, which can contain millions of embryos. Blunt End Sea Hares have lifespans of approximately one year.
Diet: Blunt End Sea Hares are herbivorous grazers that feed on a wide variety of brown, red, and green algae. They extract the pigment from the algae and use it as an ink that they secrete as a defense mechanism to avoid predation.
Predation: Blunt End Sea Hares are preyed on by crabs, fish, lobsters, sea anemones, and sea stars.
Ecosystem Interactions: In some regions Blunt End Sea Hares host the Star Pearlfish, Carapus mourlani, in a commensal relationship. It is unknown if other species of pearlfish do this where Star Pearlfish are absent. Otherwise, the commensal, parasitic and symbiotic relationships the Blunt End Sea Hares have not been documented.
Human Impact: Monomethyl Auristatin E (MMAE) is harvested from the Blunt End Sea Hare and when linked to a monoclonal antibody is used as an anti-cancer agent. They are also closely related to the California Sea Hare, Aplysia californica, which has been widely studied by neurobiologists due to its abilities of learning and memory. This marine species is also often used in large saltwater aquariums to control the growth of algae. Lastly, the eggs of the Blunt End Sea Hare are consumed as a delicacy in the Philippines, called lukot. From a conservation perspective they have not been formally evaluated however they are fairly common with a wide distribution and should be considered to be of Least Concern.
Synonyms: Patella auricularia, Aplysia ecaudata, Aplysia gigas, Aplysia hasseltii, Aplysia teremidi, Aplysia truncata, Dolabella andersoni, Dolabella callosa, Dolabella cheni, Dolabella ecaudata, Dolabella gigas, Dolabella hasseltii, Dolabella rumphii, Dolabella rumphii var. maculosa, Dolabella scapula, Dolabella variegata, Patella auricularia, and Patella scapula.