California sea slug 532057 225959025 2008-07-16T05:29:19Z 203.99.195.64 {{Taxobox | name = ''California Sea Slug'' | image = Aplysia_californica.jpg | image_width = 250px | regnum = [[Animal]]ia | phylum = [[Mollusca]] | classis = [[Gastropoda]] | subclassis = [[Orthogastropoda]] | superordo = [[Heterobranchia]] | ordo = [[Opisthobranchia]] | subordo = [[Anaspidea]] | superfamilia = [[Aplysioidea]] | familia = [[Aplysiidae]] | genus = [[Aplysia]] | species = '''''A. californica''''' | binomial = ''Aplysia californica'' | binomial_authority = ([[James Graham Cooper]], [[1863]]) }} The '''California sea slug''' (''Aplysia californica'') is also commonly called the '''California sea hare''', and this is because the shape of all ''Aplysia'' species is reminiscent of the shape of a rabbit or [[hare]]. Sea hares (family [[Aplysiidae]]) are a kind of shell-less sea [[snail]], a [[marine (ocean)| marine]] [[opisthobranch]] [[gastropod]] [[mollusk]]. This particular [[species]] lives in [[California]] and northern [[Mexico]]. The California sea hare can be very large, the maximum recorded length of being 75 [[Metre#SI multiples|cm]] (30 [[inch]]es) when crawling and thus fully extended. Most adult specimens are half or less than half that size. A closely related species, ''Aplysia vaccaria'', the black sea hare, can be even larger still. Like all ''Aplysia'' species, the California sea hare is [[herbivorous]]. Its diet consists primarily of red and brown [[seaweed]], which gives the animal its typically dark coloration. When it is considerably disturbed, as shown in the photograph on the right, the sea hare is capable of releasing reddish-purple ink (much like an octopus does) from a gland in its mantle cavity. == Life cycle == Like all sea hares, the California sea hare is [[hermaphrodite|hermaphroditic]], acting as male and female simultaneously during [[mating]]. The eggs are yellow, but after 8 to 9 days change into a brown color before hatching into [[larva]]e. When this annual animal is laying eggs, it has reached the end of its life. Its lifetime depends somewhat on the temperature of the water: 14-25 degrees [[Celsius]] is best, but a cooler temperature delays spawning and extends its life somewhat. == Laboratory use == ''Aplysia californica'' has become a valuable [[model organism|laboratory animal]], used in studies of the [[neurobiology]] of [[learning]] and [[memory]], and is especially associated with the work of [[Nobel Laureate]] [[Eric Kandel]]. Its ubiquity in [[synaptic plasticity]] studies can be attributed to its simple [[nervous system]], consisting of just a few thousand large, easily-identified [[neuron]]s. Despite its seemingly simple nervous system, however, ''Aplysia californica'' is capable of a variety of non-associative and associative learning tasks, including [[sensitization]], [[habituation]], and [[classical conditioning|classical]] and [[operant conditioning]]. Study typically involves a reduced preparation of the [[Aplysia gill and siphon withdrawal reflex|gill and siphon withdrawal reflex]]. == References == * [http://www.rsmas.miami.edu/groups/sea-hares/ NIH/University of Miami National Resource for Aplysia Facility] == External links == * [http://www.seaslugforum.net/aplycali.htm ''Aplysia californica'' photos, from the Sea Slug Forum] * [http://www.brembs.net/learning/aplysia/aplysia.html Learning in ''Aplysia californica'', from brembs.net] (photos) * Photos from [http://www.mondomarino.net/ricerca/index.asp?view=ico&genere_opt=contiene&genere=aplysia MondoMarino.net] [[Category:Aplysiidae]] [[Category:Model organisms]] [[Category:Animal testing]] [[de:Kalifornischer Seehase]] [[it:Aplysia californica]]