Care
Possibly more familiar to anglers than pond keepers, tench are a native fish that have found a place in garden ponds thanks to their bottom-dwelling lifestyle. Wild fishes are found in still waters with muddy bottoms, where they grub around in search of insect larvae and edible detritus - a feeding style that endears them to pond keepers as they have a reputation for cleaning up any scraps overlooked by other fish. Their value as working fish comes more from the fact that their activity stirs sediment which can then be removed by filtration. Tench have small scales and thick body mucous, so much so that they gained a folklore reputation as "doctor fish" which other species would rub against to benefit from the healing power of their slime. This is obviously untrue but it's unusual to see these hardy fish looking unwell, apart from when they occasionally lay on the sides to rest during cold winter weather.
A quietly social species, tench are best kept in pairs or small groups whose activity can often be tracked by watching for bubbles rising from any pockets of sediment they disturb while feeding. Once they learn where the food comes from, these fish may well feed from the surface alongside goldfish and other species. Tench are totally unaggressive but will feed on a range of invertebrates that includes small pond snails and may be uncomfortable in the bare surroundings of a koi pond.
Although widely known as green tench, mature specimens often display a bronze sheen better seen from the side " not a perspective offered by most pond fish. The domesticated golden form is often smaller than the wildtype and may be a better choice for more modestly sized garden ponds, although still growing larger than goldfish.
Feeding
Tench prefer sinking foods, but will learn to surface for other treats. Pond flakes, pond pellets, pond sticks, live/frozen foods etc will usually all be eagerly taken.
Breeding
Tench breed during May to August, in shallow water amongst dense vegetation. The adhesive green eggs, which stick to the aquatic plants, can number in the hundreds of thousands. After 6-8 days (temperature dependant), the eggs will hatch and the larvae will remain attached to the plants for several days.
