the PERCH; a genus of fishes belonging to the order of thoracici. The head is furnished with scaly and serrated opercula; there are seven rays in the membrane of the gills; and the fins on the back are prickly. There are 38 species, principally distinguished by peculiarities in the back fin. The most remarkable are,
1. The fluviatilis, or common perch, hath a deep body, very rough scales, and the back much arched. The colours are beautiful; the back and part of the sides being of a deep green, marked with five broad black bars pointing downwards; the belly is white, tinged with red; the ventral fins of a fine scarlet; the anal fins and tail of the same colour, but rather paler. In a lake called Llyn Rhiwlyn, in Merionethshire in Wales, is a very singular variety of this fish; the back part is quite hunched, and the lower part of the backbone next the tail strangely distorted: in colour and other respects it resembles the common perch, which are as numerous in this lake as the deformed fish. They are not peculiar to this water; for Linnaeus takes notice of them in a lake at Fahlun in his country. It is said that they are also met with in the Thames near Marlow.
The perch was much esteemed as food by the Romans, nor is it less admired at present as a firm and delicate fish; and the Dutch are particularly fond of it when made into a dish called water-souchy. It is a gregarious fish; and loves deep holes and gentle streams; is exceedingly voracious, and an eager biter: if the angler meets with a shoal of them, he is sure of taking every one.—It is a common notion that the pike will not attack this fish, on account of the spiny fins which the perch erects on its approach. This may be true of large fish; but it is well known that small perchs are the most tempting bait which can be laid for the pike. The perch is very tenacious of life, and has been known to survive a journey of 60 miles in dry straw. It seldom grows to a large size; though Mr Pennant mentions one that weighed nine pounds; but this, he tells us, is very uncommon.
2. The labrax, or bass, is a very voracious, strong, and active fish. Ovid calls them rabidi lupi, a name continued to them by after writers; and they are said to grow to the weight of fifteen pounds. The irides are silvery; the mouth large; the teeth are situated in the jaws, and are very small: in the roof of the mouth is a triangular rough space, and just at the gullet are two others of a roundish form. The scales are of a middling size, are very thick set, and adhere closely. The body is formed somewhat like that of a salmon. The colour of the back is dusky, tinged with blue. The belly is white. In young fish the space above the side-line is marked with small black spots.—It is esteemed a very delicate fish.
3. The perca marina, or sea-perch, is about a foot long: the head large and deformed; eyes great; teeth small and numerous. On the head and covers of the gills are strong spines. The colour red, with a black spot on the covers of the gills, and some transverse dusky lines on the sides. It is a fish held in esteem at the table.
4. The cernua, or ruffe, is found in several of the English streams: it is gregarious, assembling in large shoals, and keeping in the deepest part of the water. It is of a much more slender form than the perch, and seldom exceeds six inches in length. The teeth are very small, and disposed in rows. It has only one dorsal fin, extending along the greatest part of the back; the first rays, like those of the perch, are strong, sharp, and spiny; the others soft. The body is covered with rough compact scales. The back and sides are of a dirty green, the last inclining to yellow, but both spotted with black. The dorsal fin is spotted with black; the tail marked with transverse bars.
5. The nilotica, or perch of the Nile, is taken about Cairo. The flesh has a sweet and exquisite flavour, and is not hard, but very white. It is one of the best fishes in the Nile; and as it is of the largest size in Egypt, it adorns a table if brought upon it entire and well fried. See Pilot-Fish.