Perch (through Fr. from Lat. perca, Gr. Tiprcn; the last word is connected with ?repKcv6s, dark-coloured, spotted), a fresh-water fish (Perca fluviatilis), generally distributed over Europe, northern Asia and North America, and so well known as to have been selected for the type of an entire family of spinyrayed fishes, the Percidae, which is represented in European fresh-waters by several other fishes such as the pope (Acerina cernua) and the pike-perch (Lucioperca). It inhabits rivers as well as lakes, but thrives best in waters with a depth of not less than 3 ft.; in large deep lakes it frequently descends to depths of So fathoms and more. It occurs in Scandinavia as far north as the 69th parallel, but does not extend to Iceland or any of the islands north of Europe. In the Alps it ascends to an altitude of 4000 ft.
The shape of its body is well proportioned, but many variations occur, some specimens being singularly high-backed, others low and long-bodied; sometimes such variations are local, and Agassiz and other naturalists at one time thought it possible to distinguish two species of the common perch of Europe; there are not even sufficient grounds, however, for separating specifically the North-American form, which in the majority of ichthyological works is described as Perca flavescens. The brilliant and striking colours of theperch render it easily recognizable even at a distance. A rich greenish-brown with golden reflections covers the back and sides, which are ornamented with five or seven dark cross-bands. A large black spot occupies the The Perch, Perca fluviatilis. membrane between the last spines of the dorsal fin; and the ventral, anal and lower part of the caudal are bright vermilion. In the large peaty lakes of north Germany a beautiful variety is not uncommon, in which the golden tinge prevails, as in a goldfish.
The perch is strictly carnivorous and most voracious; it wanders about in small shoals within a certain district, playing sad havoc among small fishes, and is therefore not to be tolerated in waters where valuable fry is cultivated. Perch of three pounds in weight are not infrequently caught in suitable localities; one of five would now be regarded as an extraordinarily large specimen, although in older works we read of individuals exceeding even that weight.
Perch are good, wholesome food, and highly esteemed in inland countries where marine fish can be obtained only with difficulty. The nearly allied pike-perch is one of the best European foodfishes. The perch is exceedingly prolific; it begins to spawn when three years old, in April or in the first half of May, depositing the ova, which are united by a viscid matter in lengthened or net-shaped bands, on water plants.
