This freshwater fish has a rounded, muscular body and small, red-orange eyes. Its mouth is rather narrow, with a small, whisker-like barbel at each corner. It ranges in colour from silver-green to dark brown, depending on the habitat. The tench measures around 30 centimetres and weighs on average 1.5 kilograms. It has a lifespan of up to 10 years. Its very small scales are deeply embedded in its thick skin, making it as slippery as an eel.
The tench can be found throughout Europe, living in lakes and slow-moving waters with muddy substrate and abundant vegetation.
A hibernating species, the tench hides in mud in the winter. It can tolerate low oxygen concentrations as well as the drying out or freezing of the ponds in which it lives. The tench is rarely found in cold or fast-flowing streams. It is mainly solitary and sedentary. It hides in dark places among aquatic vegetation at the bottom of the lake or river and feeds on invertebrates (insect larvae, earthworms and molluscs), which it digs out of the mud. The adult fish also feed on aquatic vegetation and organic debris.