Tench

About

The tench is a European pond fish that turns up now and then in aquarium shops as a palm-sized, olive-green juvenile with tiny red eyes and skin so thickly slimed it feels rubbery. FishBase records the adult at 70 cm and 7.5 kg, and Lithuanian anglers routinely take 30-40 cm fish out of ordinary lakes, so the honest answer about a tank is that there isn't one: this is a garden-pond animal. It is native to Lithuania, common in almost every lake, oxbow and slow river here, and in May 2015 a public vote named it the country's national fish. It is famously tough — it feeds at night on the bottom, buries itself in mud to overwinter, and survives water holding as little as 0.3 mg/l of dissolved oxygen, conditions that would kill a carp. The ornamental golden strain sold for garden ponds is the same species in a different coat.

Care

A pond animal, not an aquarium one. Give it a still, well-planted pond of at least 2,500 litres with a soft silty bottom it can root through, deep enough not to freeze to the floor, and keep two or three together — they are entirely unaggressive and quietly social. It lives at 4-24 °C and wants no heater; a tropical community tank is the wrong home in every respect. It eats small pond snails as it forages, so do not build the display around them. In Lithuania the rule that matters most is about the water outside the pond: releasing or moving wild animals requires advance notice to the Environmental Protection Department and its approval, and introducing them requires a permit. A golden tench is the same species as a wild one, so tipping it into a local lake would not make hybrids — it would breed straight into the native population and dilute the local stock, and that is what the notification and the permit exist to stop. Anglers here must return any tench under 25 cm.

Diet

Nocturnal bottom feeder: chironomid larvae, snails and small clams, plus detritus and plant matter. In a pond it takes sinking pellets, granules, flake and frozen foods and will learn to feed at the surface.

Telling males from females

What works for this species, most reliable first.

• Breeding tuberclesStrong · only in breeding condition — they vanish out of season

  Goldfish and their cyprinid relatives grow small white bumps on the gill covers and leading pectoral rays when they come into breeding condition.

Also in these lists

Similar species

Same category and the closest water parameters — if this species isn't quite it, start here.

Sold in Lithuania

These Lithuanian shops listed this species in their public catalogue (checked August 8, 2026). Stock moves — ask before you travel.

These links are unpaid: we get nothing for them and ask for nothing.

Frequently asked questions

What tank size does a Tench need?

A Tench needs an aquarium of at least 2500 litres (660.4 US gallons) with a footprint at least 200 cm (78.7 in) long — for this species, swimming length matters as much as raw volume.

What water parameters does a Tench need?

Tench does best at 4–24 °C (39.2–75.2 °F), pH 6–8.5 and a general hardness of 5–25 °dGH.

What group size does a Tench need?

Tench is a social species — keep a group of at least 2 so natural behaviour emerges and stress stays low.

Is the Tench suitable for beginners?

Tench sits in the middle of the difficulty scale — manageable for a careful beginner who has done the reading, but it has specific needs worth researching first.

Sources

• FishBase — Tinca tinca (Tench)
• Vikipedija — Paprastasis lynas
• e-TAR — Mėgėjų žvejybos vidaus vandenyse taisyklės (aplinkos ministro įsakymas Nr. D1-14, suvestinė redakcija)
• Lietuvos Respublikos aplinkos ministerija — Keičiasi laukinių gyvūnų, augalų ir grybų rūšių introdukcijos, reintrodukcijos ir perkėlimo reikalavimai
• Maidenhead Aquatics (Fishkeeper) — Golden Tench, Tinca tinca
• Medžioklė ir žvejyba — Žvejybos taisyklės, mažiausi leidžiami sugautų žuvų dydžiai