Tench

The tench or doctor fish (Tinca tinca) is a freshwater and brackish water fish of the cyprinid (commonly called 'carp') family found throughout Eurasia from Western Europe including the British Isles east into Asia as far as the Ob and Yenisei Rivers. It is also found in Lake Baikal. It normally inhabits slow-moving freshwater habitats, particularly lakes and lowland rivers.

Ecology

The tench is most often found in still waters with a clay or muddy substrate and abundant vegetation. This species is rare in clear waters across stony ground, and is absent altogether from fast-flowing streams.

It tolerates water with a low oxygen concentration, even being found in waters where the carp cannot survive.

Tench feed mostly at night on algae and benthic invertebrates of various kinds that they root up from the bottom.

Breeding takes place in shallow water usually among aquatic plants where the sticky green eggs can be deposited. Spawning usually occurs in summer, and as many as three hundred thousand eggs may be produced. Growth is rapid, and fish may reach a weight of 0.11 kg (0.25 lb) within the first year.To spawn at all, the following conditions must be met :-the water temperature needs to be 18 degrees or more for 10 days or Longer     

     Like all fish, the air pressure is very important to them, We Call it The Barometric Pressure or sea level pressure.

 and it can range from somewhere in the 800 Millibars Range up to 1045 Millibars (the BAR is a unit of PRESSURE)

It is vital for them to Know What this Pressure is, at any given time, so they can regulate their SWIM BLADDER.

Our equivalent are called semicircular ear canals, this how we keep our balance,

We all feel a lot better with high pressure, because we don't need to expend as much energy to move around, or work.

and its exactly the same for fish, thats why, waters fish better when the pressure is higher.

You can find out what this pressure is for any hour of the day for our water, by clicking on the Tab for weather data,

and scrolling down the page to the hourly forecast, and look at the  SP  column which have figures like 1021 in this colour. 

Morphology

Tench have a stocky, carp-like shape, olive-green skin, darker above and are almost golden below. The caudal fin is square in shape. The other fins are distinctly rounded in shape. The mouth is rather narrow and provided at each corner with a very small barbel. Maximum size is 70 cm, though most specimens are very much smaller. The eyes are small and red-orange in colour.

Sexual dimorphism is weak, limited to the adult females having a more convex ventral profile when compared with males. Males may also possess a very thick and flattened outer ray to the ventral fins. The tench has very small scales, which are deeply imbedded in a thick skin, making it as slippery as an eel. Folklore has it that this slime cured any sick fish that rubbed against it, and from this belief arose the name 'doctor fish'.

Economic Significance

Tench are edible and considered to have a fine flavour, working well in recipes that would otherwise call for carp. They are an important target for coarse anglers and are also used as fodder for predatory species such as bass. Tench, particularly golden tench, are also kept as ornamental fish in ponds and less frequently aquaria.

Angling

Large tench may be found in gravel pits or deep, slow-moving waters with a clayey or silty bottom and lots of aquatic vegetation. The best methods and bait to catch Tench are float fishing and legering with a swim feeder using maggots, sweetcorn, pellets, bread and worms as hook bait and groundbait in the swimfeeder if you are not float fishing. Due to the Tench being a bottom feeder it is ESSENTIAL that your bait is resting on the bottom of the lake/pond/canal bed when float fishing - use a plummet to make sure your bait is resting on the bottom by an inch or two. Fish over 1 kg (2 lb) in weight are very strong fighters when caught on a rod.