Finescale tigerfish

The finescale tigerfish or Indonesian datnoid (Datnioides microlepis) is a large, striking predatory fish from the rivers of Southeast Asia. Its range includes the Malay Peninsula and western Indonesia, where it is found in the Perak and Selangor river systems of Peninsular Malaysia, the Batang Hari and Musi watersheds of Sumatra, and the Kapuas basin of Borneo. It is an exclusive inhabitant of large, deep, lowland freshwater rivers and enters flooded forests during the annual wet season. In the ornamental trade it is the most widely available tiger perch, distinguished from its rarer congener D. pulcher by its dirty yellowish-grey base colour and 6–7 wide dark bars on the body.

This species reaches an impressive 40–50 cm (16–20 in) in standard length in adulthood, making it suitable only for the largest private aquaria or public installations. Juveniles and subadults appreciate well-decorated planted aquaria with driftwood roots and branches, while larger individuals are less demanding of décor. The species produces a significant amount of waste, necessitating large external filtration with robust heater protection, as adults have been known to damage submerged equipment. They do not travel well and can be challenging to stabilise post-import.

In the aquarium, D. microlepis is a piscivorous predator that should be offered strips of fish flesh, whole prawns, mussels, live river shrimp, and larger earthworms for adults, while juveniles accept bloodworm, small earthworms, and chopped prawn. Adults only require feeding 2–3 times per week. Best maintained singly or in a group of five or more to diffuse aggression, they are compatible with similarly-sized robust fish. Water temperature should be 20–28°C, pH 5.5–7.5, with a hardness of 36–268 ppm. Breeding has not been recorded in captivity.