A trout taken in Llynallet, in Denbighshire, which is famous for its excellent kind, was singularly marked and shaped; it measured seventeen inches in length, depth three and three quarters, and weighed one pound ten ounces; the head thick, nose sharp, both jaws as well as the head, of a pale brown, blotched with black; the teeth sharp and strong, dispersed in the jaws, roof of the mouth, and tongue (as is the case with the whole genus, except the gwinniad, which is toothless, and the grayling, which has none on the tongue), the back was dusky, and sides tinged with a purplish bloom, both above and below the side line, which was straight, and marked with deep purple spots, mixed with black. The belly was white; the first dorsal fin was spotted; the spurious fin brown, tipped with red; the pectoral, ventral, and anal fins of a pale brown; the edges of the latter white; the tail very little forked when extended.
Some peculiar remarks upon the various sorts of trout in the northern counties of England, and of their growth and age, have been given by a very experienced angler, to the following effect:—That he does not undertake to determine whether the river or burn trout are of one species: in many points the trout taken out of the same river and same pools will agree, and in some shall vary; so that, if the difference were owing to the water or food, he could say nothing against their being of one species: he believes they spawn promiscuously together, are all similar in shape, in the number of their fins, and their fins being disposed in the same places. Whether the colour of the spots make any specific variety, he leaves to the decision of naturalists; but, in his opinion, the so much esteemed char, both red and white, is only a meer or marsh trout, and the colour perhaps owing to the sex. In several of the northern rivers he has taken trouts as red and as well tasted as any char, and whose bones, when potted, have dissolved, like those of the char. That about Michaelmas he had caught trouts of a coppered hue, without spots; the flesh when dressed, was like bees-wax, and well tasted: that likewise in April he took one of these trout twenty-eight inches and thick in proportion, which boiled yellow, but was equally good; and this he thinks was the bull trout mentioned by Walton, and several authors, as extraordinary both for its size and goodness, and to be found no where but in Northumberland. He records a still larger fish caught in the same river (the Cocquet) by him in September, near Brenkburn Abbey; the length, which was nearly a yard, did not strike this gentleman so much, as the bright spots upon the lateral line; by which it appeared to him to be an overgrown burn trout, and neither a salmon, salmon-trout, nor the same with those two he thought were the bull trout.
Walton mentions the Fordwich trout taken in the river Stour, of which only one instance was ever known of their being caught by the angle, and are said to be delicious eating; one weighing twenty-six pounds, and of a most beautiful colour, was taken with a net in December 1797; they grow to a larger size.
The burn or river trout, with plenty of food and good water, grows rapidly; several experiments were made in ponds fed by river water, and some by clear springs, into which the young fry have been put at five or six months old (that is, in September or October, reckoning from April, when they first come from the spawning-beds) at which time they will be six or seven inches long; in eighteen months the change has been surprising; he has seen a pond drained ten months after being thus stocked, which was in July, when the fish were fifteen months old; some were fifteen or sixteen inches, others not more than eleven or twelve; the fish were returned into the pond, and it was again drained the March following, when some were twenty-two inches, and weighed three pounds; others were sixteen inches, and some not more than twelve.
In March, or, if mild open weather, in February, trouts begin to leave their winter quarters, and approach the shallows and tails of streams, where they cleanse and restore themselves to health; as they acquire strength they advance still higher up the rivers, until they fix upon their summer residence, for which they generally choose an eddy, behind a stone, a log, or bank that projects forward into the water, and against which the current drives; whirlpools and holes into which sharps and shallows fall, under roots of trees, and in places shaded by boughs and bushes; in small rivers they frequently lie under sedges and weeds, especially in the beginning of the year, before their perfect strength is recovered; but when in their prime, they feed in the swiftest streams, and are often found at the upper end of mill-pools, at locks, flood-gates, and weirs, also under bridges, or between two streams running from under their arches, and likewise in the returns of streams, where the water seems to boil; in the decline of summer, they lie at mill-tails, or the end of other streams, and in the deep water.
Trout spawn, or deposit their ova and seminal fluid in the end of the autumn or beginning of winter, from the middle of November till the beginning of January; their maturity depending upon the temperature of the season, their quantity of food, &c. From some time (a month or six weeks) before they are prepared for the sexual function, or that of reproduction, they become less fat, particularly the females; the large quantity of eggs and their size, probably affecting the health of the animal, and compressing generally the vital organs in the abdomen. They are at least six weeks or two months after they have spawned before they recover their flesh; and the time when these fish are at the worst is likewise the worst time for fly-fishing, both on account of the cold weather, and because there are fewer flies on the water than at any other season.