Order:	Cypriniformes
Family:	Cyprinidae
Genus and species:	Leuciscus cephalus

William Yarrell (1836) in "A History of British Fishes":

THE CHUB.

THE SKELLY. Cumberland.

Leuciscus	cephalus,	Chub,	Flem. Brit. An. p.187, sp. 64.
Cyprinus	"	Linnæus. Bloch, pt. i. pl. 6.
"	"	Linnæus. Bloch, pt. iii. pl. 97.
"	"	Chub,	Penn. Brit. Zool. vol. iii. p. 485.
"	Jeses	"	Don. Brit. Fish. pl. 115.

THE CHUB is a well-known fish that is common in the Thames, and many other rivers of England: it is said to be plentiful in the Wye, and other rivers of Wales : it is the Skelly of Cumberland, so called on account of the large size of its scales ; it is also recorded as an inhabitant of the Annan, and other rivers in the south of Scotland.
In its nature the Chub is timid, frequenting deep holes in the more quiet parts of the sides of the stream, and sheltering itself generally under or near any bush or tree that will screen it from view. It feeds on worms and on insects in their various stages ; and is mostly caught by anglers with a fly or other bait at the surface of the water, by a mode of fishing called dibbing. The Thames anglers for Chub "cause themselves to be landed on an ait in the river, the banks of which, under the shelter of the willows, with a long rod, a short line, and a lively cockchafer, they often have good sport." The insect used as bait, whatever it happens to be, whether large moth or cockchafer, hangs pendent from the point of the rod, just touching the water ; and by repeatedly but gently tapping the butt-end of the rod, the bait is moved in a manner exactly resembling the struggles of a living insect that had by accident fallen into the water.
Mr. Jesse says of the Chub, detained with other fish where their actions could be noticed, that they were always restless and shy, but could never resist a cockchafer when thrown to them.
The Chub spawns about the end of April or the beginning of May but does not acquire a large size ; five pounds' weight is the most that I can find recorded. It is considered a coarse fish, and broiling with the scales on is one of the best modes of preparing it for table.
The length of the head compared to the length of the head and body to the end of the fleshy portion of the tail is as one to four ; the depth of the body rather greater than the length of the head ; the mouth large ; the head wide or chubby ; the nostrils in a circular depression, one-third nearer the eye than the end of the nose ; the diameter of the eye equal to one-fifth of the length of the whole head : the scales on the body large ; the number forming the lateral line forty-four, with an oblique line of six scales above it to the base of the dorsal fin, and of three scales below it to the origin of the ventral fin ; the lateral line descending by a gentle curve till even with the end of the pectoral fin-rays then straight to its end.
The dorsal fin commences half-way between the point of the nose and the end of the fleshy portion of the tail ; the first ray short, the second the longest, both simple ; the others branched, diminishing in length gradually to the last, which is the shortest ; the seventh ray as long as the base of the dorsal fin : the pectoral fin rather small ; the ventral fin arising on the same vertical plane as the dorsal; the anal fin large, commencing in a line with the end of the dorsal fin when its rays are pressed: the tail large and forked. The fin-rays in number are -

D. 10 : P. 16 : V. 9 : A. 11 : C. 19.

The colour of the top of the head blackish brown, with a streak of the same dark colour passing down behind the free edge of each operculum as far as the origin of the pectoral fin : the whole of the upper part of the back bluish black, the edge of each scale the darkest part ; the sides bluish white, passing into silvery white on the belly: the dorsal and caudal fins dusky; the pectoral fins reddish brown ; the ventral and anal fins reddish white ; the irides golden yellow, the upper part dusky ; cheeks and gill-covers rich golden yellow.
The fish described was a male of thirteen inches in length, and the milt appeared on pressure ; the season backward. May 9th, 1835,

Frank Buckland (1880) in "Natural History of British Fishes":

THE CHUB.

(Leuciscus or Cyprinus cephalus)

Local names: Chevin, Loggerhead, Poll, Pollard, Skelley (Eden, Carlisle), the Headed Dace, Lob or Bottling. French: Le Chevanne, Dobule, Le Vilain Testard. German: Deckkopf, Der Hitel, Schuppfisch, Döbel. Italian: Capitone.

THE Chub is remarkable for his hawk like quickness of sight; even the shadow of the rod or a passing cloud will make him sink instantly. It will be found that he has a very large air bladder, which enables him to ascend and descend in the water at will, with great rapidity.
The chub is found about mills, piles of bridges, weirs, in eddies, steep banks overhung with willows. He is a greedy fish, and will eat almost anything that falls into the water. When trolling for pike with a gorge bait below a weir, I had a run, and instead of a jack I caught a chub. When the chub is not full grown it is very difficult to know it from a dace (Leuciscus vulgaris).
A writer in the Fisherman’s Magazine (No. 10, p. 14) gives the following diagnostic marks: “It is not in the proportions of the two fish, but in their colour, that the most ready and convenient mark of identification is to be looked for. By bearing the following rule in mind no fisherman can ever be in doubt as to whether the fish he has in his basket is a chub or a dace. The ventral (or belly) fins of the dace are greenish with a slight tinge of red, whilst the anal fin has no red about it whatever. In the chub both these fins are of a brilliant pink colour.”
It is quite evident that the French anglers have much trouble to catch M. Chevin. We read that the “defiance and experience of the chub are very great. They have very little appetite, being placed, like Æsop's animal, in the middle of the cheese. Living in clear water, they see the fishing line, and turn up their nose at it in a disdainful manner." Another remark: “the angler wants to catch him with an invisible line ; alas! one cannot find such an article.”
“The chevin common is the grand Seneur, for he lives at his ease. In the winter in the sun, in the summer in the shade of big trees; in hot weather on the surface of the water, in cold weather at the bottom, in deep and tranquil water; hence the wise angler will recollect when it is possible to fish for him near the top, and when it is cold, near the bottom."
The chub has the same fault as the Yorkshireman's horse - he is very bad to catch, and is no good when he is caught. His body contains an enormous quantity of hair like bones. These bones are not placed without symmetry, and a chub, therefore, when made into a skeleton, either by gentles or the Dermestes beetle, forms a very beautiful object. Why a chub has such a remarkable skeleton I know not; and I should be much obliged if any of my readers could find out why the chub requires such a complicated system of bones. Mr. Chub is a great insect eater, and one of his objects in waiting under trees is to catch the caterpillars and other insects which fall off the leaves. He is especially fond of grasshoppers, cockchafers, the large black slug, the large hairy caterpillar (but the angler should be careful not to get any of this caterpillar's hairs into his eye); he also likes a bluebottle fly. He will probably take a black-beetle, and any one who could find any economic use for blackbeetles would be a public benefactor. He has large leathery lips and a great mouth. “He bites so eagerly that when he takes the bait, his jaws are sometimes heard to chop."
A capital plan to catch chub, where there are not too many trees, is to cross line for them ; that is, one fisherman walks on one side of the river, the to other on the other. The lines must be joined together in the middle and the baited hooks suspended therefrom by thin gut, and then dropped gently on the stream. Besides insects, the chub is very fond of old Cheshire cheese, and also the spinal marrow of a sheep or ox, called pith. I have also a strong notion that caviare made into paste would fetch him nicely. Although the chub has no teeth in his mouth, the angler may soon ascertain, by putting his finger well down into a live fish's throat, that he has teeth in his gullet ; these are very pretty objects, they are easily taken out of the fish, and easily cleaned by scraping.
Chub spawn in April. Little or nothing is known of their mode of spawning, or where the eggs are deposited, whether they sink or float, whether they are cohesive or not, how long the eggs take to hatch out; all of which, I trust, some of my readers will kindly elucidate by actual observation.

Alwyne Wheeler (1969) in "The Fishes of the British Isles and North West Europe":

Chub

Leuciscus (Squalius) cephalus (Linnaeus, 1758)

NAMES Fr. Chevaine; Du. Kopvoorn; Ge. Dobel; Nor. Orbug; Sw. Färna.

IDENTIFICATION The body is rather cylindrical, thick-set, with a broad, blunt head (from above). The mouth is large and terminal; its angle reaches to the eye-level. The dorsal fin origin is behind the base of the pelvic fins, its free edge convex or square cut; the free edge of the anal fin is convex. Large scales. It grows to a length of 24 in (61 cm), but the usual length lies between 12 and 20 in (30-51 cm). The British record fish weighed 10 lb 8 oz (4.76 kg); but 18 lb (8.16 kg) fish have been reported on the European mainland.
The chub is dark green or grey on the back, shading to metallic green or blue on the sides and silvery yellow ventrally. The pelvic and anal fins are yellow, often with a rosy tint, the other fins grey. The scales are dark-edged, giving a network appearance.
D. III/8-9; A. III/7-9; lateral line scales 44-6; transverse series 7-8/3-4; pharyngeal teeth in two rows 5 + 2 each side (Fig. 69).

BIOLOGY The chub is found in rivers, particularly those with clean, running water, but, uncommonly, also in stagnant reaches and lakes. In places it occurs in brackish water. The young fish are gregarious, but are rarely found in large shoals. Large chub are usually solitary, possessing, and defending from others of the same species, a `territory' in the river.
At spawning time (May to June) the male chub is covered with small white tubercles. Spawning takes place when the water temperature reaches at least 15°C (59°F), so it may be delayed, until mid-July even, after a late spring. The young fish spawn in shoals near plants and over gravelly shallows. The largest fish are said to spawn later and in pairs, but this is still unproven. The eggs adhere to plants and gravel, are 1.5 mm in diameter, and hatch at normal temperatures in from eight to ten days. The alevins are 7.5 mm long at hatching. Their growth is believed to be remarkably slow at first, reaching only a little more than one inch (2.6 cm) in their first year. From their second year they grow faster and reach about 10 in (25 cm) at six years old. The males mature at three or four years, the females at five or six; males rarely live longer than twelve years, and the largest chub are usually females.
Chub have a reputation for being wholly predators on small fish, but this is an oversimplification of their diet. Small fish of up to 8 in (20 cm) have a large dietary range, and eat caddis and beetle larvae, mayfly and stonefly nymphs, freshwater shrimps (Gammarus), water-bugs and molluscs, together with algae and plant material. They also eat fish. For larger chub fish are the dominant food (up to 30 per cent of the food), with vegetable material next in importance, followed by the larger insect larvae and chance items, like small watervoles (Arvicola) and terrestrial insects. The fish eaten are varied, including eels, gudgeon, dace, roach, young chub, young trout and occasionally minnows.
The chub is a valued angling fish on account of both its size and the skill needed to capture specimen fish. Its flesh is poor eating and nowhere is it regularly caught for food. Chub are competitors for food with young salmon and trout, and they also eat their parr when available. Their relatively restricted distribution, however, makes their threat to game fisheries minimal. Chub are eaten by many fish-eating predators-when young by herons, kingfishers, pike, trout and chub, as adults probably only by otters.

DISTRIBUTION

Eastwards to the U.S.S.R. Subspecies in northern Italy, southern France and northern Spain. L. cephalus cabeda Risso, 1826, in central Italy and the Adriatic basin. L. cephalus albus Bonaparte, 1838, and in southern Spain L. cephalus pyrenaicus Gunther, 1868.