MFK UK Episode 2 Tench


Feeder Fish
Original poster
MFK Member
Jun 2, 2005
Leeds , England
This is the second part of a Series of UK Native fish which i'm going to share with all the members of MFK.

Weight : Rarely 4.5kg (10lb), very few over 5.5kg (12lb).
Length : Rarely exceeding 60cm.
Age : Maximum 14 years.
Location : Lakes, canals and lowland rivers.
Behaviour : Mostly solitary, occasionally in small groups.
Preferred : habitat Shallow still water, dense weed, silt substrate.
Feeding : May-September, active benthic foraging at dawn and dusk.
Natural food : Zooplankton, benthic invertebrates such as molluscs.
Maturity : 3-5 years, 20-24°C.
Fecundity : 300,000-400,000 eggs per kg of body weight.
Spawning times : May-August.
Spawning : Dense weed, shallow water, low or no flow.
Migratory : habits Limited home range, localised spawning.
Predators : Pike

Tench - the Doctor Fish

The tench was once commonly nicknamed the ‘doctor fish’ because sick fish were said to rub themselves against its thick mucus covering, which it was thought had healing properties.

The mucus was even used for human medicine at one time. However it seems that the fishy physician cannot heal itself, as tench are susceptible to many external parasites and the mucus is clearly not effective in preventing such infestations.

Tench can be readily distinguished from other members of the carp family, to which it belongs, by its body shape and colouration. It has a stocky build and all its fins have smoothly rounded margins. It is dark brown or olive green on the back, shading to bronze on the lower flanks. The scales are small and the skin is very slimy. At each corner of the mouth is a small barbel. There are no reports of hybrids with other species in Britain.

The tench is one of the few coarse fish where the sexes can easily be determined by looking at them. The mature male fish has a greatly thickened second ray and longer pelvic fin.

Distribution, feeding and spawning of tench
The tench occurs across most of Britain except the north of Scotland, and throughout Europe and temperate Asia. It has been distributed widely because of its interest to anglers, aquarists and commercial fish farmers. Tench live in slow-flowing or still waters, usually where there is rich vegetation and a soft bottom.

Tench usually lead a relatively solitary existence but congregate in small groups in late spring and summer prior to spawning. They are reported to spend winter hibernating in soft mud, but in some waters can occasionally be captured during this period.

Tench feed mostly on crustaceans, insect larvae (especially midges) and pea mussels, which it sifts from the soft substrate. This feeding activity tends to release gasses from the mud, and sends up the tell-tale bubbles to the surface which are a sign that tench are feeding below. Feeding activity peaks at dawn and dusk.

Tench require higher temperatures for spawning than most other native coarse fish, the optimum being in the range of 20-24 oC. It then follows that they spawn later than other coarse fish, usually between June and August.

Spawn is usually released in batches every few days. Very large numbers of small eggs are produced which stick to submerged vegetation. Survival in the first year is often poor due to heavy predation on the eggs and fry, and the short growing season remaining after hatching. Because survival over the first winter can be so poor, tench stocks are often dominated by a few good year classes.

Growth rates are varied, depending on temperatures and feeding conditions. They usually reach between 40g (10cm) and 300g (30cm) at three years of age, but exceptionally can reach 800g. Most of the largest tench are caught at the start of the season when they are heavy with spawn.

The tench has suffered in many waters from the introduction of carp, which out-compete it for food. Tench may also be out-competed by bream in waters with low densities of submerged vegetation.

This fish is popular with anglers because of the strong fight it offers and has inspired a number of anglers to specialise in its capture. The strength of the fight is made possible by its sturdy body and scoop-like fins.

It is rather shy, and may ignore baits, but if a suitable bait can be found in summer when the fish are feeding heavily, large catches can be made by individual anglers. Worms, maggots and bread are popular baits, but swan mussels may also be used.

For many years the tench record stood at 3.86kg, but the number of large tench appears to have increased in recent years and the record is now 6.9kg (15lb 3oz). The reason for this is unknown, but might be related to recent warm summers and the use of high protein baits promoting good growth.


Tench 1.jpg

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