Taxonomy & naming
Pethia meingangbii was originally described as Puntius meingangbii by Arunkumar and Tombi Singh in 2003, from specimens collected at Moreh Bazar on the Lokchao River, Manipur, India. The species was later transferred to the genus Pethia following the revision by Pethiyagoda et al. (2012), which dismembered the old catch-all genus Puntius into several well-supported lineages. The Catalog of Fishes records the valid combination as Pethia meingangbii (Arunkumar & Tombi Singh, 2003), with parentheses around the authority reflecting the move from the original genus.
A junior synonym exists: Puntius bizonatus Vishwanath & Laisram, 2004, described from overlapping material in Manipur and subsequently subsumed under P. meingangbii. The ResearchGate-accessible article by Vishwanath and Laisram (published in the Journal of the Bombay Natural History Society, 101(1):130–137, 2004) also treats Puntius species of Manipur and confirms the Moreh type locality. The IUCN assessment lists both synonyms explicitly.
The genus Pethia groups small, often colourful cyprinids across peninsular India and Sri Lanka, separated from the Puntigrus, Systomus and other post-Puntius genera on morphological and molecular grounds. Within this genus, P. meingangbii represents a northeastern outlier: most Pethia species are peninsular Indian or Sri Lankan, but this species reaches into the Chindwin–Irrawaddy drainage of Manipur and Myanmar.
Morphology
Pethia meingangbii is a small, laterally compressed barb of the typical Pethia build — deep-bodied relative to its length, with a rounded snout and small terminal mouth. Its most distinctive external feature is a red-coloured caudal fin, which inspired both the Manipuri common name (Ngakha-Meingangbi, "red-tailed fish") and the species epithet meingangbii.
FishBase does not report a maximum total length for this species, and detailed meristic and morphometric data from the original description are not widely reproduced in the secondary literature. Size is likely in the range typical for the genus — a few centimetres standard length — but specific figures are not confirmed from the available sources and are not stated here.
Habitat
The type locality is the Lokchao River at Moreh Bazar, in the Yu River drainage of Manipur, India. The Yu River flows westward into the Chindwin, which in turn feeds the Irrawaddy in Myanmar — placing this species in a trans-boundary Chindwin–Irrawaddy drainage. The IUCN assessment recognises nine known locations across this drainage in both Manipur and Myanmar, with an estimated extent of occurrence of approximately 10,116 mi².
FishBase characterises the species as a tropical freshwater benthopelagic fish, inhabiting permanent rivers, streams, lakes and pools. The Lokchao River near Moreh is a lowland river system in a region of subtropical hill country; water parameters for the species are not specified in the available sources beyond the general tropical freshwater assignment.
Feeding
No detailed dietary studies for Pethia meingangbii are available in the accessible literature. The available sources characterise it as a freshwater benthopelagic fish, which is consistent with the foraging habits typical of small Pethia species: opportunistic omnivory, taking small invertebrates, organic detritus, algae and plant material from or near the substrate.
In Manipur, the species is consumed locally as food, suggesting it attains a body size useful for subsistence fisheries and is present in catchable numbers in its native rivers.
Mating
No spawning observations for Pethia meingangbii have been published in the available sources. Like all Pethia and the broader barb family, it is almost certainly an egg-scattering, non-guarding spawner. In typical Pethia courtship, a driving male pursues a ripe female through vegetation or over the substrate, and eggs and milt are released together with no subsequent bond or territory.
The fertilised eggs are adhesive and settle among plants or onto the substrate, where the adults take no further interest in them. No nest is constructed and no parental care of any kind is provided.
Breeding
No captive breeding records for Pethia meingangbii are documented in the available sources. Based on the uniform reproductive biology of the genus, breeding would follow the egg-scattering pattern common to all barbs: scattered adhesive eggs deposited among fine-leaved plants or over the substrate, hatching within one to two days at ambient tropical temperatures, with adults removed promptly to prevent egg predation.
The species has not entered the ornamental trade in meaningful numbers, and captive husbandry data are correspondingly sparse.
In the aquarium
Pethia meingangbii is essentially absent from the ornamental trade and is not a species commonly encountered outside its native range. The IUCN assessment notes only very small-scale sales at Moreh Market, driven by local food use rather than the aquarium hobby. No dedicated husbandry profiles exist in the major hobby sources reviewed.
Anyone working with this species should provide conditions typical for small riverine Pethia: clean, well-oxygenated freshwater in the tropical temperature range, a sandy or fine-gravel substrate with plant cover, and neutral to slightly acidic water chemistry. As with all Pethia, it should be kept in groups to express natural schooling behaviour and to reduce inter-individual aggression.
Conservation
Pethia meingangbii is assessed as Least Concern (LC) on the IUCN Red List, with the assessment date of 24 February 2010 and the assessment published in 2015. Nine locations are recognised across its Chindwin–Irrawaddy range in Manipur and Myanmar. The population trend is listed as unknown.
Despite the Least Concern designation, the IUCN assessment flags expected threats from anthropogenic activities near the Lokchao River type locality, arising from the proximity of Moreh town — a significant India–Myanmar international trade hub. Increased infrastructure, urbanisation, and economic activity in border zones of this kind typically bring habitat modification, water quality impacts, and increased extraction pressure. The species' restricted extent of occurrence (~10,116 mi²) and limited number of known sites mean that localised degradation could reduce its range meaningfully. Ongoing monitoring in Manipur and across the Myanmar portion of the Yu River drainage would be warranted.