Sea hare 532909 225073644 2008-07-11T19:25:46Z UnitedStatesian 3461395 add WL {{Taxobox | name = Sea Hares | image = Aplysia_californica.jpg | image_width = 200px | image_caption = ''[[Aplysia californica]]'', a typical sea hare | regnum = [[Animal]]ia | phylum = [[Mollusca]] | classis = [[Gastropoda]] | subclassis = [[Orthogastropoda]] | superordo = [[Heterobranchia]] | ordo = [[Opisthobranchia]] | subordo = '''Anaspidea''' (=Aplysiomorpha) | subordo_authority = P. Fischer, 1883 | subdivision_ranks = [[Family (biology)|Families]] | subdivision = *Superfamily [[Akeroidea]] **[[Akeridae]] *Superfamily [[Aplysioidea]] **[[Aplysiidae]] }} '''Sea hares''' ('''''Aplysia'' ''' species and related genera) are very large sea [[slug]]s with a soft internal shell made of protein. These are [[marine (ocean)|marine]] [[gastropod]] [[mollusc]]s in the family [[Aplysiidae]] and superfamily [[Aplysioidea]]. The [[common name]] "sea hare" derives from their rounded shape and from the two long [[rhinophores]] that project upwards from their heads and that somewhat resemble [[rabbit]] ears. The original author P. Fischer described this taxon at unspecified rank above family <ref>{{cite book | title=Manuel de conchyliologie et de paléontologie conchyliologique fasc. 6| last=Fischer| first=P.| date=1883| pages=p. 513-608| publisher=Savy | location=Paris}}</ref>. In 1925 [[Johannes Thiele|Thiele]] established this taxon as a suborder. Since the taxon Anaspidea was not based on an existing genus, this name is no longer available. It has been replaced in the new [[Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005)]] by the [[clade]] [[Aplysiomorpha ]]. The scientific name for the order in which they are classified, the (Anaspidea), is derived from the [[Greek language|Greek]] for "without a shield" and refers to the lack of the characteristic head shield found in the cephalaspidean opisthobranchs. Many anaspideans have only a thin, internal and much-reduced shell with a small [[mantle (mollusc)|mantle]] cavity; some have no shell at all. All species have a [[radula]] and gizzard plates. ==Description== Sea hares are mostly rather large, bulky creatures. The biggest species, ''[[Aplysia vaccaria]]'', can reach a length of 75 cm and a weight of 2 kg and is arguably the largest gastropod species. Sea hares have soft bodies with an internal shell, and like all opistobranch mollusks they are [[hermaphrodite|hermaphroditic]]. ==Life habits== [[Image:Swa hare DSC01663.JPG|thumb|250PX|left|Sea Hare at Big Island of Hawaii]] Sea hares are herbivore/herbivorous, and are typically found on seaweed in shallow water. It seems to be the case that some young sea hares are capable of burrowing in soft sediment leaving only their rhinophores and mantle opening showing. Sea hares have an extremely good sense of smell. They can follow even the faintest scent using their [[rhinophores]], which are extremely sensitive chemoreceptors. Their color corresponds with the color of the seaweed they eat: red sea hares have been feeding on red seaweed. This [[camouflage]]s them from predators. When disturbed, a sea hare can release ink from its ink glands, providing a potent deterrent to predators. This release acts as a smoke screen, while at the same time, adversely affecting the smell sensors of their predators. In a small environment, this ink could be toxic to the inhabitants. The color of the ink is white, purple or reddish, depending on the color of the pigments in their seaweed food source. Their skin contains a similar toxin that renders sea hares largely inedible to many predators. ==Human use== ''Aplysia californica'' is a typical example of a sea hare, and is noteworthy for its usefulness in studies of [[neurobiology]] because of the unusually large size of the axons that are a part of its nerve cells. == Notes == {{reflist}} ==References== {{Commonscat|Anaspidea}} {{Wikispecies|Anaspidea}} * http://www.seaslugforum.net/display.cfm?id=4210 * http://www.cabrilloaq.org/critter1.html [[Category:Gastropods]] [[Category:Opisthobranchia]] [[de:Breitfußschnecken]] [[fr:Anaspidea]] [[it:Anaspidea]] [[nl:Anaspidea]] [[ja:アメフラシ]] [[no:Anaspidea]] [[fi:Merijänikset]]