BIOTIC Species Information for Psammechinus miliaris
|Researched by||Lizzie Tyler||Data supplied by||University of Sheffield|
|Refereed by||This information is not refereed.|
|Distribution and Habitat|
|Distribution in Britain & Ireland||All British and Irish coasts. Evenly distributed in the southern North Sea but scarce in northern North Sea.|
|Global distribution||From Trondheim Fjord in northern Norway, inner Danish waters from the Skaw into the western Baltic, Iceland, British Isles, south to the Atlantic coast of Morocco and the Azores. Not in Greenland, the Mediterranean or Atlantic coasts of America.|
|Biogeographic range||Not researched||Depth range||0 - 100 m|
|Migratory||Non-migratory / Resident|
|Distribution Additional Information||The species is found in the intertidal and subtidal, occasionally as deep as 100 m (Mortensen, 1927) but more commonly between 16 -70 m (Cranmer, 1985) or 0 -10 m in Scottish sea lochs (Kelly, 2000).
On the west coast of Scotland Psammechinus miliaris typically occurs in dense, localized populations in sheltered areas of sea lochs (Davies, 1989; Holt, 1991). Its distribution frequently coincides with that of the brown seaweed %Laminaria saccharina%, with Psammechinus miliaris occurring on the fronds as well as on rock surfaces below the fronds. Some populations are exposed to air at low spring tides, and are found attached to the underside of rocks, boulders and seaweed, or shallowly buried under gravel on the foreshore (Kelly, 2000). Individuals from the intertidal and subtidal habitats on the west coast of Sweden were termed 'Z' and 'S' forms by Lindahl & Runnström (1929). The 'Z' form lived in the 'seaweed region' and were larger and darker than the 'S' forms found at greater depths.Comely (1979) described a population of Psammechinus miliaris from a %Zostera marina% bed in a stable salinity, shallow inlet in Loch Sween, Scotland. Theses individuals were found on the bottom mud and attached to the rhizomes of Zostera at depths of 1 -2 m. Very young individuals have been found in the holdfasts of Laminaria from the Clyde Sea, Scotland (Moore, 1971).
Psammechinus miliaris is often found on man-made surfaces such as bridge supports and wrecks.
|Substratum preferences||Large to very large boulders
Artificial (e.g. metal/wood/concrete)
Gravel / shingle
|Physiographic preferences||Open coast
Strait / sound
Ria / Voe
|Biological zone||Mid Eulittoral
|Wave exposure||Moderately Exposed
|Tidal stream strength/Water flow||Moderately Strong (1-3 kn)
||Salinity||Variable (18-40 psu)
Full (30-40 psu)
|Habitat Preferences Additional Information|
|Distribution References||Hayward & Ryland, 1995b, Hayward et al., 1996, Gage, 1991, Cranmer, 1985, Bedford & Moore, 1985, Allain, 1978, Hancock, 1957, Rasmussen, 1973, Mortensen, 1927, Jensen, 1969, Bruce et al., 1963, MBA, 1957, Massin, 1999(b), Aquascope, 2000(a), Kelly & Cook, 2001, Lindahl & Runnström, 1929, Comely, 1979, Davies, 1989, Holt, 1991, Ursin, 1960, Larsson, 1968, Leighton, 1995, Moore, 1971, Hayward & Ryland, 1990, Julie Bremner, unpub data,|