[Jordan and Evermann, 1896-1900, p. 1134.]
The white perch resembles its larger relative, the striped bass, in the number, outline, and arrangement of its fins, and in its deep caudal peduncle without longitudinal keels. But it is a deeper bodied fish, (only about 2½ to 3 times as long as deep, not counting the caudal fin); and it is more flattened sidewise (p. 390). The dorsal profile of its body is more convex than that of a bass, but its head is rather noticeably concave and its mouth is smaller. Furthermore, there is no free space between the two dorsal fins of the white perch, whereas they are separated by a short interspace in the striped bass. The perch has fewer rows of scales between gill cover and base of tail than the bass (about 48 in the white perch, 60 or more in the striped bass), and its anal spines are much stouter than those of the bass with the second and third about equal in length (graduated in the bass); also it usually has only one spine (sometimes two) at the margin of the gill cover. Finally, there is a constant difference in color.
The first dorsal fin (9 spines) of the perch is rounded in outline with its third and fourth spines longest, and although there is no free space between the two dorsal fins they are entirely separated by a deep notch. The second dorsal fin (1 spine and 12 rays) is rhomboid in outline and so short that it leaves a rather long caudal peduncle bare. The anal fin (8 to 10 rays preceded by 3 stout spines) originates under the middle of the second dorsal and is of the same shape as the latter. The ventrals originate a little way behind the pectorals and each ventral is armed with one stout spine at its forward margin. Both the pectorals and the ventrals of the perch are larger, in comparison with the size of the fish, than those of the striped bass.
The upper surface is variously olive, dark grayish green, or dark silvery gray, shading to paler olive or silvery green on the sides and to silvery white on the belly, while large fish often show a bluish luster on the head. The fins often are more or less dusky. The ventral fins and the anal fin are sometimes rose-colored at the base. The sides of young specimens are marked with pale longitudinal stripes but these usually fade out with growth.
White perch are occasionally as much as 15 inches long, 5 inches or more deep, and 2 pounds or a little more in weight; but the average is 8 to 10 inches long and 1 pound in weight, or less.
The white perch is much more closely restricted in its seaward range than the bass, for while they are taken in undiluted sea water along southern New England, and at various other localities thence westward and southward, they are much more plentiful in ponds connected with the sea, in the brackish water of bays behind barrier [page 406] beaches, in estuaries, and in river mouths. White perch also occur landlocked in fresh-water ponds in many places.
They are ordinarily found in shallow water, usually not deeper than perhaps a fathom or two, but sometimes as deep as 10-21 fathoms in Chesapeake Bay. However, they are not bottom fish (except in winter), but wander from place to place in small schools. Apart from this, they are resident throughout the year wherever found. In winter they congregate in the deeper parts of the bays and creeks, where they either hibernate, or at least pass the cold season in a sluggish condition.
When living in salt or brackish water white perch feed on small fish fry of all kinds, young squid, shrimps, crabs, and various other invertebrates, as well as on the spawn of other fish, of which they are very destructive. Swarms of young perch, for instance, have been seen following the alewives around the shores of ponds on Marthas Vineyard, eating their spawn as it was deposited. They bite freely on almost any bait, natural or artificial.
Along southern New England the white perch spawn in April, May, and June. Presumably the season commences a few weeks later around the Gulf of Maine, but definite data are lacking. Those living in salt water run up into fresh or slightly brackish water to spawn. The eggs (about 0.73 mm. in diameter, with large oil globule) sink and stick together in masses, or to any object on which they chance to rest. Incubation occupies about 6 days at a temperature of 52°. The newly hatched larvae are about 2.3 mm. long with the vent some distance behind the yolk sac and with very little pigment. In five or six days after hatching the head begins to project forward, the yolk sac has been partly absorbed and branched pigment cells have appeared on the oil globule. The late larval and post larval stages have not been described.
Atlantic coast of North America from the Gulf of St. Lawrence and Nova Scotia to South Carolina, breeding in fresh or brackish water and permanently landlocked in many fresh ponds and streams.
The white perch inhabit salt, brackish, and fresh water indifferently along the shores of southern New England. But while this is a familiar fish in many ponds throughout northern New England, New Brunswick, and Nova Scotia, they are found regularly in only a few estuarine situations north of Cape Cod, and they hardly belong to the fish fauna of the open Gulf. Thus we have heard only vaguely of them in Duxbury Bay and in the North and South Rivers in Marshfield; and we had not been able to satisfy ourselves of their presence in the salt creeks about Cohasset, Mass. (localities apparently suited to it) until the summer of 1950, when white perch running-up stream to a pond were reported there. Storer long ago described white perch as brought to Boston market from the mouths of neighboring rivers and from ponds to which the sea had access. And white perch run in salt and brackish reaches of the Parker River in northern Massachusetts, providing fishing for many small boat anglers in spring and summer.
Ordinarily white perch are so scarce along the open coast from Cape Cod northward that they did not figure in the statistics of the shore fisheries of any part of Massachusetts Bay from 1907 to 1928. And ordinarily they are not common along the coast of Maine; none was reported from the shore fisheries of Maine in 1905 or 1919, and only 400 pounds in 1902; none at all of late years. But they appear locally, however, in unusual numbers on rare occasions. Thus it is probable that certain unfamiliar fish taken at Beverly on the north shore of Massachusetts Bay during the summer of 1950, and in Casco Bay, were white perch. No less than 1,600 pounds of white perch were reported for the shore fisheries of the short coast line of New Hampshire in the year 1912: Casco Bay saw a run of them in the summer of 1901 when local fishermen, not knowing the fish, dubbed them "sea bass"; and they have been reported at Eastport, Maine. But apparently they do not occur around the shores of the Bay of Fundy, either in salt water or in brackish. And there is no reason to suppose that white perch were more regularly plentiful along the coast of the Gulf of Maine than they are today.[page 407]
In more eastern Nova Scotian waters, also, perch are "less often seen" in salt and brackish water than in fresh and they appear to be restricted, in the eastern side of the Gulf of St. Lawrence, to the "estuarine transition" from salt water to fresh.
The white perch is of considerable commercial importance wherever it is abundant in tide waters. The commercial catch in Chesapeake Bay, for example, was 1,143,700 pounds for 1946, 1,851,000 pounds for 1947. And several millions of artificially hatched fry are released there yearly. It also affords good sport to many anglers wherever it is plentiful, both in brackish water or in fresh. But it is not important in the open Gulf of Maine in either of these respects.
 Hildebrand and Schroeder (Bull. U. S. Bur. Fish., vol. 43, Pt. 1, 1928, p. 245) report ripe specimens as deep as 9½ to 21 fathoms in Chesapeake Bay.
 In Chesapeake Bay they spawn chiefly in April and May, but they are known to do so exceptionally in December (Hildebrand and Schroeder, Bull. U. S. Bur. Fish., vol. 43, Pt. 1, 1928, p. 245).
 Ryder (Rept. U. S. Comm. Fish., (1885) 1887, p. 518) describes the early development.
 Reported by Lenore Williams, Salt Water Sportsman for June 30, 1950.
 Only recent years from which detailed information is available.
 Moore, Boston Herald, for August 7, 1950.
 Vladykov and MacKenzie, Proc. Nova Scotia Inst. Sci., vol. 19, 1935, p. 91.
 Huntsman, Trans. Roy. Soc. Canada, Ser. 3, vol. 12, Sect. 4, 1918, p. 63.