Roach (Rutilus rutilus)
Roach are the commonest freshwater fish in Britain and can be found in almost every water. The average mature roach is between 8" and 10" long. A roach of 1lb is a good fish in any water. Fish weighing 2lb are not too common. Fish above this size are, for most anglers, the fish of a lifetime. Their size is determined by their environment, with larger fish coming from rich waters. Spawning is a communal affair and such indiscriminate spawning gives rise to hybridisation with other species. Roach/bream hybrids and roach/rudd hybrids are common, which can make true identification difficult. In summer, roach can be caught at all depths, but in winter seem loathe to come off the bottom. Water colour is important. In bright conditions and clear water, even the finest tackle is quite visible. They are not predatory, and their diet is varied, their natural food is water plants, algae such as silkweed and insects.
Perch (Perca fluviatilis)
The perch likes to linger close to banks and vegetation. Young perch usually form small shoals, while older perch become more isolated and solitary. They feed on aquatic invertebrates and small fishes, although older and larger perch live almost exclusively on other fish. This fish grows up to around 12" to 16" in length and an average perch will probably weigh about 1lb.Perch were among the commonest of fish in the UK, but in the 1970s they suffered a disaster. Perch "ulcer disease" killed most of them. However, they have multiplied in the years after and sometimes large numbers of stunted perch can be found. Females normally grow larger than males and begin spawning at around three years old. Males mature when much smaller and ripe fish of only 2-3 inches and six months old have been found. Perch are also known as the Red Fin in Australia.
Carp (mirror and common) (Cyprinus carpio)
Carp were probably introduced to Britain by the Romans - although the exact date is uncertain - and were a food fish of that time. Early records describe an ecclesiastical feast in 1279, at which over 100 carp were eaten. It seems likely that they were mainly stocked in monastery ponds and were uncommon everywhere else. The carp is largely a bottom feeder, using its producible mouth to suck up detritus off the bottom for the algae, worms and crustaceans it contains. However, in warm weather carp will come to the surface and can be seen sucking with their large mouths. They can then be tempted on floating baits such as bread crust, with exciting results. In ideal conditions carp can reach 40lb in weight in just seven or eight years. In the wild, they will grow more slowly and carp weighing over 20lb are highly prized specimens. Spawning takes place in late spring or early summer in shallow water that has not dropped below 17C (63F) at all for 14 consecutive days. A large female can lay over one million eggs, but their survival depends on high temperatures. They can live to around 40 years old.
Crucian carp (Carassius carassius)
These are a hardy fish which can survive in water where most other fish cannot, such as relatively acid water that become temporarily deoxygenated or freezes over in winter. They will sometimes hybridise with the common carp, but the resulting offspring will be sterile. Spawning takes place in summer and requires a water temperature of at least 13C (56F). The eggs stick to water plants, and after they hatch, the young fish will attach to the stems and absorb their yolk sac for two days. Crucian carp are a small member of the carp family and usually average about 1lb. They easily become stunted in enclosed water. Unlike other members of the carp family this fish does not have barbells in the corner of its mouth. They generally stay on the bottom, but can be tempted up in the water. When fishing for them, they can provide very delicate bites which are not easily seen.
Tench (Tinca tinca)
The tench is one of the few European fishes whose sex can be recognised at first glance. The males have longer and stronger pelvic fins than the females. Males mature at three years old and females at four years. Of all the carp family, tench are the latest to spawn. Before they spawn, the water temperature must be at least 18C (64F) for two weeks. For this reason, they do not spawn every year in the British climate. Large females lay up to 500,000 eggs, but lakes rarely become over-populated because enormous numbers of tench die in their first year. The tench loves to root around in the bottom silt for food, and also loves dense vegetation. It can tolerate very low oxygen levels. It is a very sturdy fish and very strong. It's back is brown/olive green and its sides have a golden hue and belly is a creamy yellow. It can grow to about 18" to 20" long and an average fish weighs around 2lb. There is a small barbel at the corner of its mouth; these are used for finding food amongst the silt. The scales are very small which gives it a very smooth and slimy feel. "Doctor fish" is an old title given to the tench because it is claimed that wounded fish rub up against it, presumably to help the healing process. In medieval times, headache, toothache, jaundice and other ailments were treated by applying tench slime.
Bream (Abramis abrama)
This is another fish that was eaten and is still sometimes eaten in mainland Europe, and large specimens are still reared for this purpose. It is a bottom feeder, and prefers slow-moving rivers, canals and still waters with a good silt deposit where they can grub around for food. It is a relatively long-lived fish, occasionally reaching 20 years of age. The bream matures after 3 or 4 years, although some males may produce milt (sperm) after two years. Fish over 10lb are sometimes caught, but in over stocks ponds and lakes, only stunted fish occur. They spawn in early summer in shallow water and is a communal affair. Sometimes the water appears to boil as hundreds of densely packed fish lay their eggs on water-weed. The eggs hatch in 3 to 12 days depending on temperature. Males develop white, warty lumps (tubercles) on the head and sides at spawning time. The body of mature bream is very deep and laterally flattened, and the head is comparatively small. When feeding they swim slowly in an almost vertical position, with their producible mouth extended forming a tube with which to suck up food from the bottom. They are a shoal fish and sometimes hundreds can be seen together. Young fish are silver in colour, while the deep bronze colour comes with maturity.
Gudgeon (Gobio gobio)
This is a relatively small fish, growing only to a few ounces and about 4"-5" long, but mostly there average about an ounce. They love a gravel bottom, where they can "feel" between the tiny stones with their barbells. They swim in tightly packed shoals, sometimes numbering many hundreds. They are usually a greyish colour with dark patches along their backs, with a metallic blue sheen along the lateral line. They are a member of the carp family, and also used to be considered a delicacy in the 19th century. Spawning occurs over a prolonged period. The eggs are large for such a small fish and vary from an off-white to a deep yellow, and some are tinged with blue. A female usually lays between 1000 and 3000 each year. Eggs hatch in about 10 days, and the young live in a shoal on the bottom at the spawning site. They mature at two or three years and only live for four to six years. They feed entirely on the bottom, eating plants, tiny creatures and occasionally fish eggs, and of course anglers' maggots.
Rudd (Scardinius erythrophthalmus)
This fish is very similar in appearance to the roach, and is often confused with it too. It is distinguished by having a smaller, more upturned mouth than the roach, and the origin or the dorsal fin is behind the base of the pelvic fin. The back is blue/green and the belly a silvery white. Apart from the reddish-gray dorsal and pectoral fins, all the other fins are deep red. The eyes are yellow to yellowish red. They swim in small shoals between the surface and mid-water, although they can still be caught near the bottom. They have great difficulty feeding from the bottom because of the protruding lower jaw. Spawning is in summer on submerged water plants. They mostly eat insects and small invertebrates, although large specimens may also take small fish. Rudd is slower growing than roach, and reach maturity at around four years and a length of around 5".