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]]