Order Perciformes
Family Nandidae
Subfamily ( Nandinae )
Genus Nandus.
Found in the fresh waters of India, Burma, and Indochina. These are big-mouthed predatory perciform fishes with flanks covered in dark spots arranged in transverse bands. They reach a length of 12-20 cm and exhibit very aggressive behavior.
— Gangetic Leaffish, Marble Dat — Nandus nandus [Hamilton, 1822]. Synonyms: Nandus marmoratus, Coius nandus. (Eng. Gangetic Leaffish, Marble Dat). India, Myanmar, Thailand – fresh and brackish waters. 20 cm, in aquarium 8-13 cm. Deep, laterally compressed body, almost straight belly and arched back. Notable is the large head with a deep mouth cleft. Its mouth is tubular, highly protrusible, with sharp, small teeth that securely hold the prey. This mouth structure allows it to seize and draw in prey almost instantaneously. Due to the highly developed spiny rays of the dorsal fin, they are often called “leaffishes”.
Body coloration is greenish-brown. Three yellow-green or olive-green irregular vertical stripes on the flanks, with black stripes and spots all over the body. Fins are greenish to yellowish with a chocolate pattern. Males are darker, more massive, with a humped profile and more developed fins. Dorsal and caudal fins are rounded. Juveniles are much more slender and yellower.
Active at twilight, this ambush predator waits for prey in planted areas. After stalking, it attacks a half-asleep victim (which can be up to half the predator’s body size) with a sudden dash from ambush. In the aquarium, it is necessary to create plant thickets and shelters made of driftwood and rocks. Lighting should be dim and diffused. They like to linger among the roots of floating plants. Small fish in the aquarium will certainly be eaten. Best kept in a species aquarium.
Well-suited for aquarium maintenance if regularly fed with live food, small aquarium fishes, or large bloodworms. They should be gradually trained to accept pieces of fish and meat. Completely intolerant of sudden water changes and significant temperature fluctuations. Reach sexual maturity by 2 years of age. Broad-leaved plants serve as a substrate; less commonly, they spawn in caves or against the aquarium glass walls. They live for about 6 years. dH 6-10°; pH 6.8-7.2; T 22-26°C.
— Bornean Leaf Fish — Nandus nebulosus [Gray, 1835]. Synonym: Nandus borneensis. (Eng. Bornean Leaf Fish). Greater Sunda Islands, India, Thailand, Indonesia, inhabits swamps, coastal lakes, rivers. 12 cm. Oval-shaped body with an arched back. The first 12 rays of the dorsal fin are spiny, the rest are soft. Caudal fin is fan-shaped.
Features a camouflage coloration of brown and fawn with irregular brown markings, allowing it to hide among leaves and unexpectedly grab unwary prey. Two brown stripes pass through the eyes, one from the snout to the origin of the dorsal fin, and another from the throat to the eyes. Fins are grayish with brown markings. Males can be dark in color and have larger fins.
Best kept in a small species tank, although they can be housed with other large species. Aquarium should have dense vegetation, including floating plants. They are nocturnal. Live food is used for feeding — small fish, insect larvae, crustaceans, worms. pH 6.9-8.0; dH 8-15°; T 23-27°C.
Monocirrhus polyacanthus, Polycentrus schomburgki.
Polycentropsis abbreviate, Pristolepis fasciata, marginata. 
