BIOTIC

BIOTIC Species Information for Clavelina lepadiformis
All Taxonomy Biology Distribution Reproduction

Researched by	Karen Riley	Data supplied by	MarLIN
Refereed by	Dr Xavier Turon
Distribution and Habitat
Distribution in Britain & Ireland	Clavelina lepadiformis occurs around most coasts of Britain and Ireland.
Global distribution	Its distribution extends from southern Norway to the Mediterranean.
Biogeographic range	Not researched	Depth range	Sublittoral to 50 m
Migratory	Non-migratory / Resident
Distribution Additional Information	The species is absent in the Bristol Channel, between Morecambe Bay and Colwyn Bay on the west coast of England, between the Firth of Forth and Newcastle upon Tyne, and the Humber Estuary and Dover on the east coast of Britain. It also has a variable abundance in Ireland. Clavelina lepadiformis is a very common shallow water sea squirt that is usually found on vertical rock faces and on the sides of boulders, to about 50 m depth down (Picton, 1997; Berrill, 1950). It is also found on shells, stones and seaweeds (Picton, 1997), is a typical species of harbour areas, commonly found growing on artificial surfaces. Naranjo et al. (1996) found that the light bulb sea squirt preferred light, shallow environments and was tolerant of salinities as low as 14 psu (Fish & Fish, 1996). It occurs in a wide range of exposure, but is most abundant in moderately exposed sites in the infralittoral zone (Picton, 1997). Naranjo et al. (1996) found that the species was dominant in a low rate of water renewal, excess silting and high suspended solid concentrations, although the species also occurred in other more wave exposed sites. In a study comparing Mediterranean and Atlantic populations of Clavelina lepadiformis in interior (harbours, marinas and fjords) and exterior (open rocky littoral) areas, Turon et al. (2003) found strong evidence that the interior Mediterranean clade (group of organisms sharing the same common ancestry) originated from the Atlantic clade. The Atlantic forms were not found to be divided between interior and exterior clades (Turon et al., 2003).

Substratum preferences	Artificial (e.g. metal/wood/concrete) Bedrock Cobbles Large to very large boulders Overhangs Small boulders Pebbles	Physiographic preferences	Open coast Offshore seabed Strait / sound Estuary Enclosed coast / Embayment
Biological zone	Sublittoral Fringe Upper Infralittoral Lower Infralittoral	Wave exposure	Very Exposed Exposed Moderately Exposed Sheltered Very Sheltered Extremely Sheltered
Tidal stream strength/Water flow	See additional information Insufficient information	Salinity	Full (30-40 psu) Variable (18-40 psu)
Habitat Preferences Additional Information
Distribution References	Fish & Fish, 1996, Berril, 1950, Naranjo et al., 1996, Picton & Costello, 1998, De Caralt et al., 2002, Turon et al., 2003,