Habitat & Distribution
This species occurs in shallow water to about 40m depth, amongst algae or Eelgrass Zostera marina where it is found clinging with its tail or swimming upright. In winter it is thought to occur in rocky areas in deeper water. This eastern Atlantic species is found from the Netherlands south to Portugal and the Mediterranean. It is recorded on south and south-west coasts of Britain and Ireland and on the north-west coast of Scotland as well as the west coasts of Orkney and Shetland. There are 26 records of this species on the ERICA (2008) database from between 1899-2003. This species' preference for shallow water habitats makes it highly vulnerable to degradation of the habitat by human activities. At some sites boat anchorage is a cause for concern.
This species is protected under Appendix II of CITES, App.III of the Bern Convention, Schedule 5 of the Wildlife & Countryside Act (1981) from 2008 and is also on the UK and OSPAR Lists of Priority Species.