G. Spinachia, Linn. Syst. Nat. torn. i. p. 492. Bloch, Ichth. pl. 53. f. 1. Don. Brit. Fish. vol. ii. pl. 45. Spinachia vulgaris, Flem. Brit. An. p. 219. Aculeatus marinus, Will. Hist. Pise. p. 340. tab. X. 13. f. 2. Fifteen-spined Stickleback, Penn. Brit. Zool. vol. iii. p. 263. pl. 50. no. 131. Id. (Edit. 1812). vol. hi. p. 356. pl. 61. Yarr. Brit. Fish. vol. i. p. 87. Le Gastre, Cuv. et Val. Poiss. torn. iv. p. 373. Cuv. Reg. An. torn. II. p. 170.
From five to six inches.
(Form). Very much elongated; the entire length ten times the depth and the breadth: lateral line marked throughout its course by a series of carinated scales, which form ridges, and render the posterior half of the body quadrangular; before the vent it is pentagonal: head one-fourth of the whole length; snout very much produced; mouth rather small; lower jaw longest: vertex flat, with a sulcus between the eyes: dorsal spines commencing immediately above the pectorals, fifteen in number, of equal length, the last excepted, which is longer and more hooked than the others; space occupied by these spines equalling nearly one-fourth of the whole length: soft fin immediately behind the last spine, of a triangular form; its greatest height equalling the depth of the body; all the rays branched: anal exactly answering to it in form, situation, and number of rays; before the first ray a short hooked spine: portion of the tail beyond these fins very much depressed, sharp at the sides, and equalling one-third of the whole length: caudal square at the end; all the rays branched: pectorals rounded, one-ninth of the entire length; the rays simple: ventral spines short and slightly curved, each accompanied by two small soft rays:
D. 15 - 6 or 7; A. 1/6; C. 12; P. 11; V. 1/2: about forty-two scales in the lateral line, all sharply keeled and slightly granulated; those on the sides of the tail forming the sharpest edge: rest of the skin smooth. Number of vertebrae forty-one. (Colours). Greenish brown; silvery beneath: dorsal and anal fins, each with a round black spot.
Found only in the sea, never ascending rivers. Not uncommon on some parts of the coast. Feeds on worms and small Crustacea, as well as on the eggs and fry of other fish. Spawns in Spring. Is stated by Cuvier to be the only known species belonging to this sub-genus.