Encyclopædia Britannica, Ninth Edition/Tench
TENCH, the Tinca tinca of naturalists, is one of the commonest and most widely spread freshwater fishes of Europe. It is generally distributed in all suitable localities throughout England, but is limited to a few lakes and ponds in the south of Scotland and in Ireland. As the tench is of comparatively uncommon occurrence in unenclosed waters, its place among the indigenous fishes of Great Britain has been denied, and it has been supposed to have been introduced from the Continent. In central Europe, however, where it is undoubtedly indigenous, it thrives best in enclosed, preserved waters, with a clayey or muddy bottom and with an abundant vegetation; it avoids clear waters with stony ground, and is altogether absent from rapid streams. The tench belongs to the family of carps (Cyprinidæ), and is distinguished from the other members of that family by its very small scales, which are deeply embedded in a thick skin, whose surface is as slippery as that of an eel. All the fins have a rounded outline; the short dorsal fin is without a spine, but the males possess a very thick and flattened outer ray in the ventral fins. The mouth is rather narrow and provided at each corner with a very small barbel. Tench if kept in suitable waters are extremely prolific, and as they grow within a few years to a weight of 3 or 4 lb, and are then fit for the table, they may be profitably introduced into ponds which are already stocked with other fishes, such as carp and pike.
Tench (Tinca tinca).
They live on small animals or soft vegetable substances, which they root up from the ground. The albino variety especially, which is known as the “golden tench”, can be recommended for ornamental waters, as its bright orange colours render it visible for some distance below the surface of the water. This variety, which seems to have been originally bred in Silesia, is not less well-flavoured than the normally coloured tench, and grows to the same size, viz., to 6 and even 8 lb.