Though normally associated with stillwaters, tench may be found in slow-flowing rivers. Among freshwater fishermen the tench has a reputation as a hardy fish and a powerful, determined fighter
The tench, Tinea tinea, is a powerful fighting fish, much valued by the freshwater specimen hunter. The species belongs to the carp family and has a short, thick-set body, oval in cross-section. A copious layer of slime almost hides the diminutive scales – smaller than the pupil of the eye – that are deeply embedded in the skin. The scale count along the lateral line varies between about 90 and 120.
The back rises gradually from the head to the dorsal fin, while the belly line is almost horizontal. Tench have a head with a slightly protruding mouth and a short pair of barbules on the upper lip. The dorsal fin is high and arched, and has three or four hard and eight or nine soft rays, and the caudal fin is wide and squarish, rather like a rudder. Pectoral and pelvic fins are thick, and the latter, in the mature male, have a sturdy ray on the outer edge.
The tench is a very hardy fish, able to live in poorly oxygenated waters and often the only species to survive pollution and oxygen starvation. It can survive out of water longer than any other freshwater fish, with the possible exception of the eel and carp, staying alive for up to two or three hours in a damp sack. This makes it an easy fish to transfer from water to water.
Mature tench vary in length from about-12 to 30in, a fish of 12in weighing about 1 Vfelb and one of 24in around 4lb. The current British rod-caught tench record stands at 10lb 1oz 2dr, caught in 1975, but this fish, like many others in excess of 6lb, contained a lot of spawn. Just how big a ‘clean* tench grows is debatable. One hears stories of anglers seeing fish well into the ‘teens’, but these are usually found to be spawning. For a ‘clean’ tench, an eight-pounder seems to be near the upper limit.
Tench at the other end of the scale are not often taken. The few waters where tench of less than a pound are caught regularly also yield other fish of only two or three ounces.