Venerupis senegalensis

Researched By	Will Rayment	Data Supplied By	MarLIN
Refereed by	This information is not refereed.
Taxonomy
Scientific name	Venerupis senegalensis	Common name	Pullet carpet shell
MCS Code	W2124	Recent Synonyms	Venerupis pullastra, Venerupis corrugata, Venerupis saxatilis
Phylum	Mollusca	Subphylum
Superclass		Class	Pelecypoda
Subclass		Order	Veneroida
Suborder		Family	Veneridae
Genus	Venerupis	Species	senegalensis
Subspecies
Additional Information	Venerupis saxatilis has a more sculptured shell than Venerupis senegalensis and is typically found attached to firm substrata in rocky crevices. It is unclear whether Venerupis saxatilis is a separate species or an ecophenotype of Venerupis senegalensis (Hayward et al., 1996).
Taxonomy References	Fish & Fish, 1996, Hayward & Ryland, 1995b, Hayward et al., 1996, Howson & Picton, 1997, Smith & Heppell, 1991
General Biology
Growth form	Bivalved	Feeding method	Active suspension feeder
Mobility/Movement	Burrower	Environmental position	Infaunal
Typical food types	Suspended organic matter, particularly unicellular algae	Habit	Burrow dwelling
Bioturbator		Flexibility	None (< 10 degrees)
Fragility	Intermediate	Size	Small-medium(3-10cm)
Height	Insufficient information	Growth Rate	1.3 mm/month
Adult dispersal potential	100-1000m	Dependency	Independent
Sociability	Solitary
Toxic/Poisonous?	No
Additional Information	Abundance Johanessen (1973a) recorded Venerupis senegalensis (studied as Venerupis pullastra) from a sheltered beach in Norway at a mean density of 31 individuals per 0.25 m². Potential production was calculated to be 20 g ash free dry weight per m²/year, including a loss of 9 g due to mortality. Growth rate Growth rate of Venerupis senegalensis varies according to environmental conditions. Quayle (1952) investigated growth rates of Venerupis senegalensis (studied as Venerupis pullastra) from Millport, Scotland. In the first year following settlement, mean monthly growth rate was 1.3 mm per month over the growing period of 6 months. Growth rate was found to increase for the first 4 years of life (maximum growth rate was ca 9 mm per season) after which it began to decrease. Within each growing season, growth rate was found to increase up to the point of spawning, after which it levelled off and then decreased. Johannessen (1973b) investigated growth of Venerupis senegalensis (studied as Venerupis pullastra) from a sheltered beach in western Norway. The spherical shell of the free swimming larvae developed into an oblong shape after settlement, presumably to aid burrowing. At a shell length greater than 40 mm, the shell shape tended towards a flattened circular form, the biological significance of which is unclear. The shell growth rate was found to be approximately constant (ca 15 mm per season) up to a shell length of 40 mm, after which it decreased. Short and/or young individuals were found to grow faster than long and/or old ones. Diet Beiras et al. (1993) investigated the effect of increasing food rations on Venerupis senegalensis (studied as Venerupis pullastra). Increased rations of algal food were found to increase ingestion rate and growth. This relationship was found to hold true up to the maximum ration of 300 algal cells/µl. However, at high food concentrations the returns diminished due to decreased absorption efficiency. The optimum food concentration for growth (i.e. maximum increase in biomass per unit weight of food) was 100 cells/µl.
Biology References	Fish & Fish, 1996, Hayward & Ryland, 1995b, Hayward et al., 1996, Johannessen, 1973a, Johannessen, 1973b, Quayle, 1952, Beiras et al., 1993
Distribution and Habitat
Distribution in Britain & Ireland	Recorded from all around the coast of Britain and Ireland where suitable habitat occurs
Global distribution	Recorded in Europe from northern Norway to the Mediterranean and in north west Africa
Biogeographic range	Not researched	Depth range	lower shore to 35 m
Migratory	Non-migratory / Resident
Distribution Additional Information
Substratum preferences	Gravel / shingle, Mixed, Muddy gravel, Muddy sand, Fine clean sand, Coarse clean sand	Physiographic preferences	Strait / sound, Enclosed coast / Embayment, Estuary, Sealoch
Biological zone	Lower Eulittoral, Sublittoral Fringe, Upper Infralittoral, Lower Infralittoral, Upper Circalittoral, Lower Circalittoral	Wave exposure	Sheltered, Very Sheltered, Extremely Sheltered
Tidal stream strength/Water flow	Moderately Strong (1-3 kn), Weak (<1 kn)	Salinity	Full (30-40 psu), Variable (18-40 psu)
Habitat Additional Information
AMBI Group (Borja et al., 2000)	I
Distribution References	Fish & Fish, 1996, Hayward & Ryland, 1995b, Hayward et al., 1996, Johannessen, 1973b, JNCC, 1999, Picton & Costello, 1998, Bruce et al., 1963, Connor et al., 1997(a)
Reproduction/Life History
Reproductive type	Gonochoristic	Developmental mechanism	Planktotrophic
Reproductive Season	See additional information	Reproductive Location	Insufficient information
Reproductive frequency	Annual episodic	Regeneration potential	No
Life span	6-10 years	Age at reproductive maturity	1 year
Generation time	1 year	Fecundity	Insufficient information
Egg/propagule size	Insufficient information	Fertilization type	Insufficient information
Larvae/Juveniles Larval/Juvenile dispersal potential >10km Larval settlement period Insufficient information Duration of larval stage 11-30 days
Additional Information	The reproductive characteristics of Venerupis senegalensis vary according to the environment. In Scotland, Quayle (1952) recorded breeding between May and September. However, in northern Spain, spawning occurred in March, April and May (Perez Camacho, 1980). Spawning occurred 2 or more times in a season in a population in western Norway (Johannessen, 1973b) and it has been recorded that spawning can occur up to 4 times per season in Venerupis senegalensis (studied as Venerupis pullastra) raised in a microsystem (Jara-Jara et al., 2000). The Spanish population of Venerupis senegalensis (studied as Venerupis pullastra) experienced constant mortality of 17.7% per annum between shell lengths of 11 and 50 mm (Perez Camacho, 1980) whereas the Norwegian population exhibited low mortality up to year 8 followed by mass mortality attributed to senility (Johannessen, 1973b).
Reproduction References	Fish & Fish, 1996, Johannessen, 1973b, Quayle, 1952, Perez Camacho, 1980, Jara-Jara et al., 2000