Pethia tiantian

Overview

From the mountains of northern Myanmar, Pethia tiantian is a peaceful small shoaler suited to seasonal temperature variation. Trade names can be misleading because an undescribed Myanmar fish is also sold under its name. Identification requires anatomical details such as the complete lateral line.

Distribution & habitat

Its known range is restricted to the remote Putao area of Kachin State, in the upper Irrawaddy system. Records come from the Mali Hka and its tributary, Nan Hto Chaung.

At the forest tributary site, clear, colorless water ran fairly rapidly through occasional riffles over rock, gravel, and sand. The channel was roughly 3 m across and generally less than 0.5 m deep. Bank vegetation shaded the water, but submerged plants were absent. A specimen from the much wider Mali Hka was collected along a shallow rocky margin; that channel exceeded 100 m in width.

Aquarium setup

Use dark substrate and dense planting for good presentation, with floating plants and woody branches providing shade. A stream-style arrangement with moderate movement is another option; strong filtration is not essential.

Seasonal variation matters more than constant tropical warmth. Avoid maintaining the upper temperature limit continuously. Whether heating is needed depends on the actual room temperature remaining within the suitable range.

Diet & feeding

Wild fish are presumed to forage on algae, diatoms, debris, and small insects, worms, and crustaceans. Captive specimens generally feed readily. Combine quality prepared foods with regular live or frozen bloodworms, water fleas, and Artemia, including plant- or algae-based ingredients in part of the dry-food ration.

Behaviour & compatibility

Peaceful behavior allows suitable small companions with matching environmental needs. Keep a mixed-sex shoal of eight to ten or more; other shoaling fishes can also reduce nervousness.

Larger groups allow males to display and establish rank among themselves, promoting more natural activity and stronger coloration.

Sexual dimorphism

Mature males are smaller, slimmer, and more intensely colored. Their sides become copper-orange in breeding condition, whereas females have a fuller outline.

Breeding

A successful breeding account specific to this species is lacking. Methods used with relatives provide an experimental starting point: a mature, dimly lit spawning aquarium, fine plants or spawning mops, or a mesh barrier that leaves fallen eggs beyond the adults' reach. A gently running air-powered sponge filter is suitable.

Related species often spawn in near-neutral water toward the warmer end of their appropriate range. Condition adults with live foods, then introduce one or two pairs, or groups of about six of each sex where space permits. Spawning commonly follows the next morning, after which adults are removed to prevent egg predation.

In those related fishes, hatching takes roughly 24–48 hours and swimming begins around a day later. Tiny starter foods precede microworms and Artemia nauplii. These timings and procedures are comparative guidance, not a demonstrated protocol for P. tiantian.

Notes

The lateral line reaches the caudal base, unlike the shortened line of several similar species. Compared with Pethia didi, the body is more slender and the dorsal fin shorter. A single dark stripe crosses each of the dorsal and anal fins, rather than the two dorsal marking series of that relative.

The last unbranched dorsal ray is thin and flexible with fine serrations. These combined features are more dependable than flank blotches or a Myanmar label alone.