Osseous tubercles in five longitudinal rows; strong and spinous.

A. Sturio, Linn. Syst. Nat. torn. 1. p. 403. Block, Ichth. pl. 88. Turt. Brit. Faun. p. 114. Don. Brit. Fish. vol. 111. pl. 65. Flem. Brit. An. p. 173. Sturio, Will. Hist. Pise. p. 239. tab. P. 7. fig. 3. Sturgeon, Penn. Brit. Zool. vol. iii. p. 124. pl. 19. no. 53. Common Sturgeon, Id. (Edit. 1812). vol. in. p. 164. pl. 22. L'Esturgeon ordinaire, Cuv. Reg. An. torn. 11. p. 379.

Length

From six to eight feet, sometimes more.

Description

{Form). Body elongated; somewhat pentagonal; with five longitudinal rows of osseous tubercles, one on the back, two at the sides, and two at the edges of the abdomen; tubercles marked with radiating striae, broad at the base, terminating above in a sharp strong spine directed backwards; those on the back more developed than the others: the whole skin rough with minute points and tubercles independently of the above larger ones: abdomen flat: head long, covered above with lozenge-shaped plates; a longitudinal sulcus on the forehead: snout depressed, somewhat corneal, rather slender and sharp-pointed; mouth placed beneath, cylindrical, small, without teeth, bordered by a protractile cartilage instead of lips: four pendent barbules on the under surface of the snout, nearer its extremity than the mouth: eyes small: nostrils near the eyes, double; the anterior orifice round, the posterior one elongated: gill-opening large; the gill-cover marked with numerous striae, radiating in all directions: a single dorsal, of a somewhat triangular form, small, placed very far back near the tail: anal also small, and nearly opposite: caudal forked; the upper lobe long and pointed, produced very much beyond the lower: pectorals'oval: vent beneath the commencement of the dorsal; the ventral fins a little in advance of it.

D. 35; A. 23; C. 125; P. 28; V. 24*.

{Colours). Upper parts gray, variegated with dusky, sometimes inclining to olivaceous; the central part of the tubercles white: beneath silvery white.

A migratory species, residing in the sea during the winter months, but entering rivers at the approach of Spring to spawn. Very abundant in many parts of the Continent, but seldom in any plenty in this country. Attains to the weight of from one hundred to three hundred pounds.

* The above fin-ray formula is from Donovan.

Pennant mentions one, taken in the Esk, which weighed four hundred and sixty pounds. Arrives at a still larger size abroad, according to Bloch and other authors. Feeds principally upon the smaller fish. Flesh much esteemed. The well,known article of food termed Caviar is prepared from the roe.