BIOTIC

BIOTIC Species Information for Cerastoderma edule
All Taxonomy Biology Distribution Reproduction

Researched by	Lizzie Tyler	Data supplied by	University of Sheffield
Refereed by	This information is not refereed.
Distribution and Habitat
Distribution in Britain & Ireland	Widely distributed in estuaries and sandy bays around the coasts of Britain and Ireland.
Global distribution	Found from the western Barents Sea and northern Norway to the Iberian Peninsula, and south along the coast of west Africa to Senegal.
Biogeographic range	Not researched	Depth range
Migratory	Non-migratory / Resident
Distribution Additional Information	Boyden & Russell (1972) compared the habitat preferences of Cerastoderma edule and Cerastoderma glaucum. They concluded that Cerastoderma edule was excluded from hypo- or hyper-saline waters by insufficient tidal flow rather than salinity itself, and that Cerastoderma edule was unable to colonize still water conditions. Brock (1979) found Cerastoderma edule in Danish fjords with little tidal range and suggested that food availability was more important. However, Cerastoderma edule and Cerastoderma glaucum may be found together (sympatric), where stable sediments and good food availability occur e.g. Zostera sp. covered silt banks (Boyden & Russell, 1972; Brock, 1979). Predation Predation has been show to influence recruitment and population dynamics in Cerastoderma edule. (Sanchez-Salazar et al., 1987a; Masski & Guillou, 1999;. Sanchez-Salazar et al. (1987a) reported that low shore cockles had high mortalities when small which decreased with size due to predation by shore crab (Carcinus maenas) in the summer months that preferred cockles <15mm in length. Higher on the shore cockle mortality was moderately in the first year (47%) but increased with size, due to predation by oystercatchers (Haematopus ostralegus) in the winter months, which prefer cockles of at least 20mm in length. As a result, the lower shore populations studied were composed of spat and fewer large individuals whereas higher shore populations contained smaller cockles. Cockles are also preyed on by the shrimp and flatfish, e.g. in Sweden Crangon crangon was a dominant predator of cockles <2mm and cockles were the dominant food for the flounder Platichthys flesus (Möller & Rosenberg, 1983). Möller & Rosenberg, (1983) noted that predators removed a significant proportion of bivalve production in years of normal recruitment, less so in years of good recruitment.

Substratum preferences	Sandy mud Muddy sand Coarse clean sand Fine clean sand Seagrass Muddy gravel	Physiographic preferences	Enclosed coast / Embayment Open coast Strait / sound Sealoch Ria / Voe Estuary
Biological zone	Upper Eulittoral Mid Eulittoral Lower Eulittoral Sublittoral Fringe	Wave exposure	Sheltered
Tidal stream strength/Water flow	Moderately Strong (1-3 kn) Weak (<1 kn) Very Weak (negligible)	Salinity	Reduced (18-30 psu) Full (30-40 psu) Variable (18-40 psu)
Habitat Preferences Additional Information
Distribution References	Seaward, 1982, Seaward, 1990, Fish & Fish, 1996, Hayward et al., 1996, Hayward & Ryland, 1995b, Tebble, 1976, Dame, 1996, Boyden, 1972, Boyden & Russel, 1972, Hancock & Franklin, 1972, Jones & Baxter, 1987a, Richardson et al., 1980, Montaudouin & Bachelet, 1996, Montaudouin, 1996, Hancock, 1967, Ducrotoy et al. , 1991, Jensen, 1993, Smaal et al., 1997, Sanchez-Salazar et al. 1987, Olafsson et al., 1994., André et al. , 1993, Masski & Guillou, 1999, Guillou & Tartu, 1994, Möller & Rosenberg, 1983, Brock, 1979, Ansell et al., 1981, Hayward & Ryland, 1990,