BIOTIC Species Information for Palinurus elephas
|Researched by||Angus Jackson & Charlotte Marshall||Data supplied by||MarLIN|
|Refereed by||This information is not refereed.|
|Distribution and Habitat|
|Distribution in Britain & Ireland||The main populations are confined to the west coast of Scotland, the extreme south-west coasts of England & Wales and the west coast of Ireland. See 'additional information' in Habitat section.|
|Global distribution||South and west coasts of the British Isles, South to the Azores, the western Mediterranean, Adriatic Sea and Aegean Sea.|
|Biogeographic range||Not researched||Depth range||5-70m|
|Distribution Additional Information||Only occasional occurrences have been noted from elsewhere and the species is now rarely seen in some areas where it was formerly (1970s) common. Records since 1950 have been included in the mapped distribution. On the south coast of Britain, the species is now only occasionally caught east of Lizard Head. In the past it has been recorded from around Plymouth and there are exceptional cases from as far east as Portland (Hepper, 1977). It is present around Lundy (Hiscock, pers. comm.), the Isles of Scilly (Hepper, 1977) and the Isle of Man (Bruce et al., 1963). In Scotland, the species is found up the west coast and along the north coast to Orkney and Shetland (Ansell & Robb, 1977; Kinnear, pers .comm.). The greatest densities are found in the southwest and become increasingly less common moving northwards (Kinnear, pers. comm.) Very occasional isolated records have been made from the east coast of Scotland suggesting that larvae can penetrate into and survive in the North Sea. This is presumably during periods when North Atlantic oceanic water intrudes further round into the North Sea (Hepper, 1977).
Reduced landings, smaller average size and general observations indicate that populations have declined considerably since the 1970's, in south-west Britain at least. Numbers in the Mediterranean have also been reduced (Campillo & Amadei, 1978). Reasons for the decline include possible over-fishing through use of more efficient capture mechanisms such as tangle nets. Environmental conditions may also play an important role (Hiscock, pers. comm., based on observations in Russell, 1973 and Wilson, 1951). Their presence only on coasts bordering the Atlantic suggests a confinement to oceanic waters (Hepper, 1977). Successful recruitment of decapod larvae may be dependent on incursions of more oceanic water (Russell, 1973).The species is generally found in open coastal areas and offshore seabeds where salinity is likely to be full (30-40 psu). The typical depth range of the species is between 5 and 70 m (Ansell & Robb, 1977; Ingle, 1997) although it has been recorded as deep as 160 m (Noel, 1999). These depths will typically cover the infralittoral and circalittoral zones of the seabed. Although typically found on rocky substrata, the species has also been recorded from finer sediments at the edge of Zostera sp. beds in Salcombe Harbour (Marine Biological Association, 1957).
Several observations suggest that the species makes active annual migrations to and from deeper water (e.g. Hunter, 1999). The populations, at least off the west of Ireland, (except perhaps for large males), move offshore into deeper waters late in the year to over-winter with the movement back inshore occurring in spring (Mercer, 1973, cited in Hunter, 1999). Migrations may be triggered by seasonal changes in sea temperature.
Large to very large boulders
|Physiographic preferences||Open coast
|Biological zone||Upper Circalittoral
|Wave exposure||Extremely Exposed
|Tidal stream strength/Water flow||Insufficient information
||Salinity||Full (30-40 psu)
|Habitat Preferences Additional Information|
|Distribution References||Hepper, 1977, Hunter et al., 1996, Hayward & Ryland, 1995b, Campillo & Amadei, 1978, Ansell & Robb, 1977, Ingle, 1997, MBA, 1957, Russell, 1973, Hunter, 1999, Mercer, 1973, JNCC, 1999, Picton & Costello, 1998, Noel, 1999, Wilson, 1951, Bruce et al., 1963, Holthuis, 1991,|