Note on the Occurrence of Echinus esculentus above Low-tide Mark on the Cornish Coast

Extract

When collecting on the shores in the Plymouth area, while a member of the Easter Class at the Marine Biological Laboratory, Plymouth, in 1921, I was struck by the absence above low-water mark of Echinus esculentus, as contrasted with its abundance in this zone at Port Erin in the Isle of Man; for there, as Chadwick states, “it may be collected by hand on the beach, and on the ruined breakwater at low-water of spring tides.” There is no record of this species except below tide-marks in the “Plymouth Marine Invertebrate Fauna” list (Journ. Marine Biological Association, Vol. VII, 1904).

In 1849 W. P. Cocks, in the Trans. Penzance Natural History and Antiquarian Society (“List of Echinodermata procured in Falmouth and Neighbourhood from 1843 to 1849”), recorded the occurrence of this species thus:—

“Echinus sphœra.—Trawl refuse; common: young specimen found attached to stones, low-water mark.”

Later (1887–8), in the same journal, G. F. Tregelles, in a paper on “Echinodermata of Mount's Bay,” makes the following statement of the species of the genus Echinus: “The commonest and largest is E. esculentus (Pennant) [E. sphœra Forbes], which literally swarms off this coast at all depths. It is brought in by trawlers; it is found in crab-pots, into which it climbs laboriously after bait; the seaweed gatherers obtain them in from one to two fathoms of water. The Mouse-hole fishermen call them ‘zarts,’ doubtless an old Cornish word.”