10 20 40 60 cm
mittakaava < 40 cm
Gösta Sundman: Suomen Kalat (Kansalliskirjasto, The National Library of Finland), Lauri Urho, Jouko Lehmuskallio, Petri Savola (Uudenmaan ympäristökeskus). All rights reserved.
- Name also: Redfin Perch, European Perch, Eurasian Perch
- Family: Perches – Percidae
- Similar species: pike-perch, ruffe
- Size: Usually 15–30 cm, 50–350 g. A 40 cm specimen weighs c. 1 kg. Perch over 2 kg are rare. Growth varies greatly with environment.
- Appearance: Deep but tapering body, larger specimens developing a hump behind the head. First dorsal fin has 14 strong spines. Posterior edge of gill cover very sharp. Scales characteristically rather large and firmly attached to skin. Rough to the feel.
- Colouring: Varies with humus content of water. Specimens from clear waters are olive green on the back and the sides have dark vertical bars. Underside pale. Pelvic, anal and caudal fins orange-red. Eye yellowish. Colouring darker in peaty waters, with back almost black and bars less prominent. Underside then also slightly darkish. The fins of such fish may be strongly red in colour.
- Reproduction: Early May in southern Finland, slightly later further north and in the sea, depending on water temperature. Eggs laid at depths of 0.5-3 m. Eggs in long gelatinous ribbons adhering to underwater vegetation.
- Food: Like most other fish, juveniles feed on plankton. Adult fish take a wide variety ranging from surface insects and other invertebrates to small fish. Large perch are mainly carnivorous.
- Distribution and habitat: Finland’s most widely distributed fish, found almost everywhere except northernmost Lapland. Even survives in peaty forest pools devoid of other species. Tolerates acidic waters but not highly eutrophic waters, or waters where the oxygen content is low in winter or that freeze through. Prefers shorelines and fairly shallow water, where it is most active in the evening and morning.
Familiar to everyone with its banded sides, perch vary considerably in size and colouration according to location. In the sea and large lakes, where food is abundant, perch grow quite rapidly, but the growth of those inhabiting smaller waters may be stunted through lack of food. Small dark perch of the same size inhabiting small ponds may in fact be quite old. They feed on their own fry each year and a new generation manages to grow only as the previous generation gradually dies off.