A long slender fish, that tends to be scaleless, the sea stickleback has usually fourteen to eighteen spines along the back, with the average number being fifteen – hence the alternative name fifteen spined stickleback. Commonly found amongst seaweeds in shallow waters, this fish is distributed along the coasts of Britain and Ireland and the rockier shores of Europe. Usually bluish to grey in colour on its upper body, with a paler, sometimes yellow underside the stickleback has small square dorsal and anal fins and a thin tail.