Originally from Asia, carp were introduced long ago to Western Europe and Britain as a food source, particularly in monastery ponds. The carp is an omnivorous bottom feeder, feeding on algae, worms, shellfish and even small fish. It thrives in still or slow-flowing rich, warm waters. Carp are among the longest-lived freshwater fish, often over 20 years and a few recorded at over 40 years. Typically they grow to 20lb (9kg), but can grow much larger in the right conditions – the world record for a carp being over 100lbs!
Spawning takes place in early summer in shallow water that has not dropped below 17 deg. C. for 14 consecutive days.
Common carp have uniform scales all over their bodies and mirror carp are distinguished by the exceptionally large scales usually present only along the lateral line region and the base of the dorsal fin.
Bream were once the staple fish of the poorer people in rural areas. In Europe it is still considered good eating but is now rarely eaten in Britain. The bream is a bottom feeder and inhabits slow-flowing rivers or lakes with rich silt deposits containing plenty of insect larvae, worms and molluscs. It is a relatively long-lived fish, occasionally reaching 20 years, and in ponds typically reach between 5–10lb (2–5kg).
Bream spawn in early summer in shallows with weed growth – the eggs are sticky, adhering to the plant growth where they hatch in about 14 days.
The coarse fish caught most in Britain is the highly adaptable roach.
Orange fins, reddish eyes and silvery scales distinguish the roach from the similar rudd, which have reddish fins and orange-yellow eyes.
The upper and lower jaws of the roach project equally, whereas the rudd’s bottom jaw is slightly longer. For the roach the front edge of the dorsal fin is above the pelvic fin base, whereas the dorsal fin starts well behind the pelvic fin base on the rudd.
Roach usually reach a length of 8″ (20cm) and may attain 14″ (36cm) – roach weighing more than 3lb (1.4kg) are relatively rare. Rudd are normally slower growing than roach and commonly reach 8–12″ (20–30 cm)
The crucian carp is amongst the smallest members of the family Cyprinidae, which includes other fish such as the common carp. Although of the same family as the common carp, the crucian carp is different in that it doesn’t have barbules and rarely reaches a weight above 3.5lb (1.58 kg). crucian carp vary in colour from gold to bronze but mainly have a brownish colouring across the back with gold or greyish green sides leading down to a yellowish or white belly.
They spawn mainly on water plants around the months of May to June.
Although mainly a bottom feeder, The crucian carp will feed at all levels and are often seen taking small insects from the surface of the water during sunny days.
The perch is a predator and feeds on small fry and small roach and rudd. The perch is distinguished by vertical dark stripes or bars on its green-grey flanks and dorsal fins.
Perch were once among the commonest fish in Britain, until the 1970s when most were wiped out by perch “ulcer disease”. Before then perch up to 8lb (3.6kg) are recorded but now rarely are found more than 3–5lb (2.3kg).
The unmistakably coloured tench was probably introduced into Britain from Europe hundreds of years ago. Thickset and deep-bodied, the tench is dark bronze green, olive green or brown above with a yellow sheen below. The eye is red and all the fins are large and rounded. The scales are small and well embedded in thick, smooth, slimy skin – in medieval times headache, toothache and other ailments were treated by applying tench slime.
Of all the carp family, tench are latest in their spawning time, often July, as water temperature must be at least 18 deg. C for two weeks. Tench weighing up to 4lb (1.8kg) are not uncommon and can reach double that size.
The golden tench is a cultivated variety and sometimes has greenish markings or spots.