The Tench(Tinca tinca) is a resilient fish with some strength. It is a member of the Carp family. It requires very little oxygen and can survive in highly polluted water and stagnant pools. It can also survive by digging itself into the mud if the the water source dries up. It will come out from the mud when it starts to fill up with water again. It can survive like this for a long time and is able to survive for a few hours in a damp sack. Tench sizes are getting bigger , this is thought to be because of water run off from fields brining fertilisers into the food chain and making the weeds, etc. more nutritious. They breed from May-July. The females grow larger than males and she will lay up to 900,000 eggs which are small and green. These adhere to the weeds. The tench matures at two to three years of age.
Dark olive green skin on back and a orange-yellow belly. Reddish eyes and a barbel in each corner of the mouth. Males and females can be differentiated by the pelvic fins - spoon-shaped in the males. There is also a golden morph ( see picture)- rare in nature, but commonly commercially bred for aquiculturists