Liocarcinus depurator

Researched By	Lizzie Tyler	Data Supplied By	University of Sheffield
Refereed by	This information is not refereed.
Taxonomy
Scientific name	Liocarcinus depurator	Common name	Blue-leg swimming-crab
MCS Code	S1580	Recent Synonyms	None
Phylum	Crustacea	Subphylum
Superclass		Class	Eumalacostraca
Subclass	Eucarida	Order	Decapoda
Suborder	Pleocyemata	Family	Portunidae
Genus	Liocarcinus	Species	depurator
Subspecies
Additional Information	Other common names include the 'swimming crab'.
Taxonomy References	Howson & Picton, 1997, Hayward & Ryland, 1995b, Hayward et al., 1996, Fish & Fish, 1996
General Biology
Growth form	Articulate	Feeding method	Predator, Scavenger
Mobility/Movement	Swimmer, Crawler, Burrower	Environmental position	Demersal
Typical food types	Polychaetes, crustaceans, molluscs, ophiuroids and fishes constitute most of the diet (Freire, 1996).	Habit	Free living
Bioturbator	Not relevant	Flexibility	None (< 10 degrees)
Fragility	Fragile	Size	Small-medium(3-10cm)
Height	Insufficient information	Growth Rate	Insufficient information
Adult dispersal potential	1km-10km	Dependency	Independent
Sociability	Solitary
Toxic/Poisonous?	No
Additional Information	Size range and size at maturity: values given are for Mediterranean individuals (Muino et al., 1999). Feeding: Swimming crabs may exploit a wide range of dietary items including algae, sponges and many small invertebrates and may be considered omnivorous. However, Liocarcinus depurator is typically a scavenger and a carnivore. Freire et al. (1996) suggest the high diversity of food items in the diet of Liocarcinus depurator is due to the versatile functional structure of the chelipeds. Host for: Abelló et al., (1988) found 5% of individuals in the northwestern Mediterranean infested with the polychaete Iphitime cuenoti. No evidence of disease in the branchial chamber was found and the authors suggest a commensal relationship between the crab and the polychaete. However, the relationship may involve some degree of parasitism. In the Firth of Lorne the parasitic nemertean Carcinonemertes carcinophila was found the gills of over 90% of Liocarcinus depurator sampled (Comely & Ansell, 1989(b)).
Biology References	Mori & Zunino, 1987, Abelló et al., 1988, Freire, 1996, Comely & Ansell, 1989(b), Muino et al., 1999, Abelló et al., 1991, Freire et al., 1996, Hayward & Ryland, 1990, Julie Bremner, unpub data
Distribution and Habitat
Distribution in Britain & Ireland	All British and Irish coasts.
Global distribution	Distributed from Norway to West Africa including the Mediterranean.
Biogeographic range	Not researched	Depth range	0 - 450 m
Migratory	Insufficient info.
Distribution Additional Information	Salinity: Liocarcinus depurator is essentially a marine species although a few individuals were found at the lower reaches of the Forth estuary where salinity varied between 24-35 psu (Mathieson & Berry, 1997).
Substratum preferences	Muddy gravel, Muddy sand, Fine clean sand, Coarse clean sand	Physiographic preferences	Open coast, Offshore seabed, Strait / sound, Ria / Voe
Biological zone	Sublittoral Fringe, Upper Infralittoral, Lower Infralittoral, Upper Circalittoral, Lower Circalittoral, Circalittoral Offshore	Wave exposure
Tidal stream strength/Water flow	Moderately Strong (1-3 kn), Weak (<1 kn), Very Weak (negligible)	Salinity	Full (30-40 psu)
Habitat Additional Information
AMBI Group (Borja et al., 2000)	I
Distribution References	Hayward & Ryland, 1995b, Hayward et al., 1996, Ingle, 1997, Mathieson & Berry, 1997, Hayward & Ryland, 1990, Julie Bremner, unpub data
Reproduction/Life History
Reproductive type	Gonochoristic	Developmental mechanism	Planktotrophic, Oviparous
Reproductive Season	Year round	Reproductive Location	Water column
Reproductive frequency	Annual protracted	Regeneration potential	No
Life span	Insufficient information	Age at reproductive maturity	1 year
Generation time	Insufficient information	Fecundity	130000
Egg/propagule size		Fertilization type	Internal
Larvae/Juveniles Larval/Juvenile dispersal potential Insufficient information Larval settlement period Insufficient information Duration of larval stage
Additional Information	Time of gametes: In the northwestern Mediterranean female moult and copulation takes place between May and July (Abelló, 1989a). Spawning: Females with eggs occur all year (Ingle, 1997) although a maximum proportion of ovigerous females has been observed indicating the existence of an annual reproductive cycle. In Plymouth, ovigerous females are reported from March to October, from April to May in Bristol, January to June in the Clyde and Argyll and from January to May in Galway (Ingle, 1997). In the warmer waters of the northwestern Mediterranean numbers of ovigerous females peak in the winter months from November to February and males were found to be sexually mature throughout the year (Abelló, 1989a). In Plymouth, Liocarcinus depurator was found to incubate three or more batches of eggs over the spring and summer breeding season (Wear, 1974). Fecundity: The number of eggs carried by ovigerous females in the north western Mediterranean ranged from about 30,000 to 230,000 clearly increasing with the size of the female (Abelló, 1989a). However, a maximum of 140,000 eggs for the largest females was estimated in the Ligurian Sea (Mori & Zunino, 1987). Age at maturity: In the Gulf of Genoa in the Ligurian Sea Liocarcinus depurator females attain sexual maturity, are fertilized and bear eggs within the first year (Mori & Zunino, 1987). Larvae: in the plankton during spring and summer in British and North Sea waters (Ingle, 1980).
Reproduction References	Abelló, 1989a, Ingle, 1997, Mori & Zunino, 1987, Ingle, 1980, Wear, 1974, Julie Bremner, unpub data