Form.—The body is moderately compressed, its greatest thickness being somewhat more than one half of its depth. Its profile is oblong, tapering more toward the tail, which is nearly cylindrical: its greatest depth is at the ventrals, and rather exceeds one-fourth of the total length, caudal included.
The head constitutes two-sevenths of the total length, and its height, at the eye, is equal to one-half its length from the tip of the snout to the point of the gill-cover. The forehead is flat, but appears depressed, owing to the convexity of the nape. The snout is a little convex. The orbits are lateral, distant more than one of their own diameters from the tip of the snout, and more than two diameters from the point of the gill-cover. The jaws are equal. The mouth descends on it runs backward, its posterior angle being under the centre of the orbit.
Teeth.—The intermaxillaries, lower-jaw, knob of the vomer, and edge of the palate-bones, are covered with very small, straight or slightly-curved, densely-crowded teeth (en velours.) The vault of the palate, posterior part of the vomer, and the pointed tongue, are smooth.
Gill-covers.—The preoperculum is narrow; its upper limb rising vertically forms a right-angle with the lower one; and its edge is armed with small spinous teeth, those on the lower limb being directed forward. The bony operculum terminates in a narrow sub-spinous point, beneath which there are three denticulations, with grooves running backward from them. An acute-pointed membranous flap prolonged from the margin of the suboperculum conceals these parts in the recent fish. The edge of the interoperculum and posterior part of the suboperculum are minutely denticulated. The edges of the humeral bones are slightly grooved and denticulated, the denticulations being more obvious in some individuals than in others.
Scales.—There are sixty scales on the lateral line, and twenty-two in a vertical row between the first dorsal and centre of the belly. The scales are rather small, their bases truncated and furrowed to near the middle (striées en éventail) by six grooves corresponding to eight minute lobes of the margin. A narrow border of the outer rounded edge is very minutely streaked, producing teeth on the margin, visible under a lens. The length and breadth of a scale, taken from the side, are about equal, being two and a half lines. A linear inch measured on the sides or belly, longitudinally, contains twelve scales, the scales on the belly having, however, less vertical breadth. On the back an inch includes seventeen or eighteen. The asperity of the scales is perceptible to the finger, when it is drawn over them from the tail toward the head. The lateral-line is thrice as near to the back as to the belly, and is slightly arched till it passes the dorsal and anal fins, when it runs straight through the middle of the tail. It is marked on each scale by a tubular elevation, which is divided irregularly by an oblique depression.
Fins.—Br. 7—7; D. 13—1 | 13; P. 14; V. 1 | 5; A. 2 | 8; C. 175-5.[[2]]
The first dorsal commences a little posterior to the point of the gill-cover and to the pectorals: its fourth and fifth rays are the highest: the first ray is slender and not half the height of the second; the last ray is so short as to be detected only by a close examination. The second dorsal commences a quarter of an inch from the first, the space between them being occupied by two or three inter-spinous bones without rays: its first ray is spinous, and is closely applied to the base of the second, which is thrice as long distinctly articulated, and divided at the tip: the remaining rays are all divided at their summits, but at their bases the articulations are obsolete. The pectorals originate opposite to the spinous point of the operculum; they are somewhat longer than the ventrals, which are attached opposite to the second spine of the first dorsal. The anal is rounded: its first ray is one-fourth part shorter than the second, both being spinous: the succeeding rays are articulated and branched, the five anterior ones being longer than the second spine, the others becoming successively shorter: its termination is opposite to that of the second dorsal. The caudal is distinctly forked, its base is scaly, the scales advancing farther on the outer rays and covering one-third of their length.
Such is the general description of the fish throughout the country at large, but great allowance must be made for accidental and local variations of color, some specimens being light-green, backed and barred with black, with silvery bellies, others exactly as portrayed above, others nearly orange, and approaching in some degree to the splendor of the goldfish.
As I have observed, no fish is more general than this in every description of waters throughout his range in the United States. From the largest rivers, so low down their channels that the waters begin to be brackish, to the smallest mountain rivulets; from the mill-pond, and small, clear mountain tarn, to the vast expanses of Huron, Michigan and Superior, they are omnipresent and numerous.
They spawn in March, each female excluding a vast quantity of spawn. So many as 992,000 ova having been taken, as it is stated by Mr. Brown in his “American Angler’s Guide,” though he does not annex his authority, from a single female.