The descriptive text, below the map, is from the Cornish Red Data Book (2009). The map on this web page depicts the organisms distribution and shows the records made pre-2000 and those made since.
Habitat & Distribution
An estuarine species which appears to be attracted to lower salinities and also the warmer waters associated with marine docks. A Lusitanian species which is rather rare in northern European waters. First discovered in Cornish waters in 1846, it was not found again until the mid-1950s, when it was caught at Swansea and Barrow-in-Furness. Subsequently it has been taken from the Severn Estuary and in the Falmouth estuary (1987). Elsewhere it is found in the Bay of Biscay, around the mouth of, and in, the Mediterranean and in the Black Sea.
I.J. Bennallick, S. Board, C.N. French, P.A. Gainey, C. Neil, R. Parslow, A. Spalding and P.E. Tompsett. eds. 2009. Red Data Book for Cornwall and the Isles of Scilly. 2nd Edition.Croceago Press.
The Cornish Red Data Book Project was led by the Cornwall and Isles of Scilly Federation for Biological Recorders (CISFBR). The full text and species accounts (minus the maps) are available on the CISFBR website.