The perch is a handsome fish, with striking looks well suited to its predatory life. Its flanks are an olive-green with six or seven black stripes, camouflaging it among weeds and reeds. The tail is rather small, so it is not a high speed swimmer, but it can cruise fairly fast for long periods.
Follow the feeding
Perch are hunters, preying on other species. Fry feed on water fleas and other tiny Crustacea but they soon graduate to insect larvae such as bloodworms. If small enough fish are available, perch switch to a mainly fish diet when they weigh about 4oz (113g). Perch that have made this transition grow very rapidly. Where there is no prey of this type, perch remain stunted, weighing only 4oz (113g) at about seven years old.
Young perch hunt in schools, lying in wait is always tail first.
Perch usually eat small fish with a l-2 lb (0.45-0.9kg) specimen typically taking prey of about l-2oz (28-57g). Odd though it might seem, perch seem particularly fond of catching and eating the fry or smaller members of their own species.
Life in school
Perch prefer slow-moving or still waters with a good head of small prey species. Good visibility is essential for their style of hunting and so they do best in clear water. They can also survive in relatively fast-flowing rivers if there is not too much suspended silt making the water cloudy. Perch are not found either in high, rocky streams or in acid lakes.
When young, perch form schools consisting of one age group but as they grow older they become more solitary. This is not because the older fish lose the instinct to form schools but is due to the shrinking of each school of perch as fish die and are eaten.
Male perch can be sexually mature at only 6-12 months old even though they are usually no more than 5-8cm (2-3in) long whereas females are seldom ready to mate until they are three years old. The females usually grow to a larger overall size than the males.
Spawning occurs between March and June when the female lays up to 300,000 eggs in lacy strands over weeds, twigs, stones or any other solid object in the shallows. The eggs begin to hatch out about a week after they are fertilized.