Sea bass Centropristes striatus (Linnaeus) 1758

BLACK SEA BASS; BLACKFISH

Description—

The sea bass is easily distinguished from the striped bass and from the white perch by the fact that the spiny and soft-rayed portions of its dorsal fin are continuous, so that there is only one long fin instead of two short separate fins. It agrees with its nearer relative the wreck fish (p. 409) in this; also with the scup (p. 411), with the rosefish (p. 430), with the cunner (p. 473), and with the tautog (p. 478). But its general form, rounded caudal and pectoral fins, and its short but high anal fin are sufficient to separate it from the scup, its color prevents confusing it with the rosefish; and no one should take sea bass for tautog or cunner; its mouth and its pectoral fins are so much larger, its caudal of different outline (cf. fig. 211 with figs. 249, 250), and the soft portion of its dorsal as long as the spiny portion. It differs from the wreck fish (p. 409), in many respects, especially in its much larger scales; in the smoothness of its head and gill covers; and in the shape of its tail fin.

It is moderately stout-bodied, about three times as long (not counting the caudal fin) as it is deep, with rather high back but flat-topped head, moderately pointed snout, a large oblique mouth, eye set high up, and one sharp flat spine near the rear angle of each gill cover. The spiny (10 spines) and soft (11 rays) portions of its dorsal fin (which originates slightly in front of the rear corner of the gill covers) are separately rounded, the latter higher than long, with the characteristic outline shown in the illustration (fig. 211). The caudal fin is rounded. In large fish one of the upper rays is much the longest, and though the resulting outline is a trivial character and variable from fish to fish it is an extremely characteristic one that is shared by no other Gulf of Maine species except the kingfish (p. 423). The anal fin (3 short sharp spines followed by 7 soft rays) originates under or very slightly behind the origin of the soft portion of the dorsal fin, which it resembles in its rounded [page 408] outline and in being higher than long. Both the anal fin and the soft part of the dorsal are noticeably soft and flexible. The pectorals are so long that they reach back almost, if not quite to the anal, broad and round tipped; a good field mark. The ventrals, too, are larger than in any other fish with which the sea bass might be confused, and they originate in front of the pectorals, whereas they stand slightly behind the latter in scup, rosefish, cunner, and tautog. The scales are rather large, but the top of the head is naked. Adult males develop a fatty hump on the back in front of the dorsal fin.

Color—

Sea bass, like most fish that lie on rocky bottom, vary widely in color, the general ground tint ranging from smoky gray to dusky brown or blue black, usually more or less mottled. The belly is only slightly paler than the sides. On every sea bass we have seen the bases of the exposed parts of the scales are paler than their margins, giving the fish the appearance of being barred with longitudinal series of dots of a lighter tint of brown than the general hue on dark fish, but pearl gray on pale ones. The dorsal fin is marked with several series of whitish spots and bands; the other fins are mottled with dusky. Young fish 2 or 3 inches long are greenish or brownish with a dark side stripe passing from eye to caudal fin, and with dark cross bars on the sides.

Size—

Sea bass grow to a length of 2 feet or more and a few reach a weight of 71/2 pounds; but northern specimens are seldom heavier than 5 pounds, and they average only about 11/2 pounds. A fish a foot long weighs about one pound, one of 18 to 20 inches about 3 pounds.

Habits—

The sea bass contrasts with the striped bass in being strictly confined to salt water. Its inshore-offshore range extends from close in to the coast line, in depths of only a few feet, out about to the 70-fathom contour line, according to the season of the year. Off New Jersey, Long Island, and southern New England they appear inshore during the first or second week in May, withdrawing again late in October or early in November.

They winter offshore along the 30- to 70-fathom zone; the depth and the distance offshore being governed, it seems, by a preference for temperatures higher than about 46°-47°.^[32]

It seems, too, that some of the population that summers off New Jersey and to the northward may combine this offshore movement with a southward migration, for sea bass form a considerable part of the catches that are made by the winter trawl fishery off Virginia and northern North Carolina from January to April,^[33] whereas they have been taken in small numbers only (though widely dispersed) off southern New England at that time of year.^[34]

During the part of the year when the sea bass are inshore they are most plentiful on hard bottom, in water less than 20 fathoms or so, often around submerged wrecks and the pilings of wharves. They are bottom feeders, subsisting chiefly on crabs, lobsters, shrimp, and various mollusks. They also eat small fish (e. g., launce and menhaden), and squid on occasion. And they take a hook readily.

The sea bass spawn in May along the North Carolina coast; from the middle of May to the end of June off New Jersey, off Long Island, and off southern New England. The eggs are buoyant.^[35] The young fry are easily identifiable as sea bass by the time they have grown to a length of 23/8 inches (60 mm.) or so.

General range—

Atlantic coastal waters of the United States, from northern Florida to Cape Cod, occasionally to Maine.

Occurrence in the Gulf of Maine—

The sea bass enters our Gulf only as a rare stray from the south, Pemaquid Point and Matinicus Island being its nothernmost known outposts. It has been taken in Casco Bay; near Gloucester (where a few have been caught in the traps); off Nahant, Salem, and Beverly in Massachusetts Bay; at North Truro and at Monomoy on Cape Cod; and 5 miles east of Pollock Rip Lightship, where a 5-pound fish was trawled in 24 fathoms, December 1930.^[36] But it has never been found in any numbers north of the elbow of Cape Cod so far as we can learn. We have never seen it in the Massachusetts Bay region, nor are fishermen of whom we have inquired familiar with it there. Sea bass, it is true, [page 409] occasionally appear in the returns of the local pound nets and traps.^[37]

But it is doubtful whether these records can be accepted, for when the name "sea bass" is used along the northern New England coast it usually is either striped bass (p. 389), white perch (p. 405), tautog (p. 478), or even rosefish (p. 430) that is meant.^[38] No sooner do we round Cape Cod to the west, however, than we find the sea bass one of the important ground fish.

Judging from its season at Woods Hole, where it is to be caught from May to October (most abundantly in July, August, and September), sea bass are most likely to be taken in the Gulf of Maine in summer, if at all, though there is one record for December. There is no reason to suppose that they ever succeed in reproducing themselves in the Gulf or in establishing a temporary foothold even if the rare migrants should spawn there.

Importance—

Too scarce to be of any importance in the Gulf, the sea bass is a very valuable food and game fish in more southern waters.