泰北虎鱼 · Mekong Tiger Perch

Overview

The Mekong tiger perch Datnioides undecimradiatus is a large freshwater predator usually marked by four relatively narrow dark bars. Commercial names can confuse it with the broader-barred Siamese tiger perch, so assess the fish rather than relying on a geographical label.

Distribution & habitat

Records are confined to the middle and lower Mekong in Thailand, Laos, Cambodia, and Vietnam, including major tributaries such as the Xe Bangfai, Mun, and Sekong. The type locality lies in the Mekong a short distance below the Khone Falls in Laos.

It uses large, deep lowland freshwater rivers and is not expected to enter brackish habitats routinely. River engineering, bank vegetation loss, pollution, and fishing for food and aquaria may place pressure on wild populations.

Aquarium setup

Start with an aquarium at least 180 cm long. Juveniles and subadults need plants, roots, and branches for cover; larger fish still appreciate overhead shelter. Routine marine-salt addition is unnecessary at any stage.

Substantial external filtration or a sump is important because the genus produces considerable waste. Adults may damage submerged equipment. Protect heaters securely or place them in a separate sump compartment.

Transport can be followed by feeding refusal and difficulty settling. During stress or at night, the body may become gray-brown or blackish while the dark bars fade, leaving outlines or spots more distinct. Interpret this alongside feeding and adjustment rather than judging one moment's color alone.

Diet & feeding

Its natural diet is chiefly fish, captured with highly protrusible mouthparts. Juveniles can take bloodworms, small earthworms, and chopped shrimp. Adults accept fish strips, whole shrimp, mussels, live river shrimp, and larger earthworms. Mature fish do not need daily meals; two or three weekly are a suitable routine.

Avoid beef heart, chicken, and other mammal or bird meat because some fats are poorly processed and may contribute to deposits and organ problems. Feeder fishes are unnecessary and may introduce parasites or disease; nutritional quality also depends on how they were conditioned.

Behaviour & compatibility

Similar-sized fishes can share a sufficiently large aquarium, although strongly territorial or competitive companions may intimidate it. Small fishes can become prey.

Juveniles may associate, but adults are generally unsociable and may attack their own species or similarly shaped fishes. Single housing is straightforward. Groups should contain at least five with correspondingly large accommodation; increasing numbers without increasing capacity is unsuitable.

Notes

The first of the four narrow bars can be interrupted over the operculum and normally does not continue across the chest or belly. An additional small, incomplete bar sometimes occurs. Small scales and a relatively straight predorsal profile provide further clues.

Northern Thai, NTT, and Thin Bar commonly refer to this species, while Siamese and Gold Datnoid more often identify Datnioides pulcher. A generic Thai tiger label is therefore insufficient for identification.