Clown Loach: Size, Care, Tank Mates and Snails

The clown loach is an orange, black-banded bottom fish from Sumatra and Borneo that is sold small but grows large and slowly: 15-20 cm is typical in aquariums and 40-50 cm has been recorded in the wild (Wikipedia). It is social, needs a group and a big tank, and is popular because it is lively and eats pest snails. Every shop fish is wild-caught or farm-bred with hormones; it does not breed in home tanks (Wikipedia; Aqua Imports).

• Three thick, black, triangular vertical bands on a whitish-orange body (Wikipedia)
• A bottom-dwelling fish that sifts through the substrate (PetSmart)
• A movable spine under each eye (the suborbital spine), used in defence; it is not venomous (Wikipedia)

Few aquarium fish combine an orange body, three broad black bars and life on the bottom, so a clear side-on photo is usually enough to confirm the species.

Wikipedia gives 15-20 cm (fork length) for most aquarium fish and 40-50 cm for wild fish. Aqua Imports tells buyers to expect 14 inches (about 35 cm) or more, reached slowly over years. The practical point is the same: the 5 cm fish in the shop will outgrow a small tank, which is why both shops ask for 120-125 gallons.

• Size and lifespan: slow growth to 15-35 cm, and Wikipedia reports lives of up to 30 years (a figure it marks as disputed)
• Group needs: kept alone or in pairs they hide; Aqua Imports says small groups are shy and rarely show their normal behaviour
• Tank size: 120-125 gallons (Aqua Imports; PetSmart)
• Disease: they are particularly prone to ich (white spot) because of their very small scales (Wikipedia)
• Medicines: PetSmart treats them as scaleless and warns to use only medications labelled safe for scaleless fish
• Clean water: Aqua Imports lists 0 ammonia, 0 nitrite and nitrate below 30 ppm

PetSmart rates the species for advanced keepers.

Partly. They eat bladder snails (Physella acuta), which makes them a common choice for snail control (Wikipedia). They are not scavengers you can leave to live on leftovers, though: Aqua Imports describes them as carnivores with a fast metabolism that need frequent feeding with a mix of prepared and frozen foods. They also sift through fine substrate, so PetSmart asks for fine or rounded gravel.

Yes, in a big enough tank. PetSmart calls them peaceful, communal bottom-dwellers, and Aqua Imports says they are generally peaceful but fast-moving, which can stress slow tank mates. Good matches are active, peaceful mid- and upper-water fish that like the same warm, soft-to-neutral water. Avoid very slow, long-finned fish, and avoid keeping them with snails you want to keep.

New owners often think a clown loach is dying. Wikipedia records that they sometimes swim on their sides or upside down, lie still as if dead, and make clicking sounds when content or when disputing territory. If breathing is normal and the fish moves when disturbed, this is usually rest, not illness. Look instead for white spots, clamped fins or rapid gill movement, which point to ich or poor water.