Channa stewartii

Channa: the name dates back to Gronow (1763) and its origin is uncertain. It may come from a Greek name for a wide-mouthed sea fish.

stewartii: named after Major Robert Stewart, Superintendent of Cachar in Assam, who sent Playfair the collection of fishes that included this species.[2]

Described from Cachar in the Barak valley of Assam, northeastern India.

It's known from the Brahmaputra basin in India and Bangladesh, and from the Ganges basin from southern Nepal eastward (Bordoloi et al., 2024). The Catalog of Fishes also lists it from West Bengal and Bhutan.

Britz et al. (2024) include it among the snakeheads of Myanmar, without giving a locality there.

Type locality is 'Cachar, Assam, India'.[2][3][4][6]

Recorded from both flowing and still water, including streams and ponds.

The region has a monsoon climate with a warm, wet summer and a cool, dry winter, and keepers maintain it with a matching seasonal drop in temperature (see 'Maintenance').[1][7]

An aquarium with base dimensions of at least 120 ∗ 45 cm48 ∗ 18 in is large enough for a single fish or a pair.

Furnish the tank densely with rocks, driftwood, plants and floating cover, arranged to give plenty of caves and to break up lines of sight between the fish.

It will escape through any gap, so the tank needs a tightly fitting cover. Leave a space between the cover and the water surface, as the fish breathe air and need access to a layer of humid air.

Keepers give it a seasonal cycle, with summer temperatures of about 24 – 25 °C75 – 77 °F and a cooler winter period of about 16 – 18 °C61 – 64 °F.[8][9]

Temperature: 16 – 25 °C61 – 77 °F

pH: 6.0 – 8.0[9]

A predator. In the aquarium it takes meaty foods, live or frozen, such as earthworms, prawn and pieces of fish, and reports say it won't eat dried foods.[9]

Aggressive towards its own kind and best kept singly or as a pair in a tank of its own.

A pair is best formed by growing on a group and removing the others once two fish have paired, as the rest are likely to be attacked.[8][9]

Females are slightly duller and more yellowish than males (Bordoloi et al., 2024).[4]

A mouthbrooder in which the male carries the eggs. In one aquarium spawning described in Practical Fishkeeping, the male brooded for ten days at 18 °C64 °F before releasing the young.

Weijola (2022) reported that in several snakeheads of the C. gachua group the female feeds the young with unfertilised eggs, and suggested that the behaviour may be found throughout the group. We have found no account of it in this species.[8][10]

Also known as the Assamese snakehead.

A member of the C. gachua group. The group holds most of the species in the genus, and includes both mouthbrooders and species that guard floating eggs (Britz et al., 2024).

Britz et al. (2024) diagnose it among the Myanmar members of the group by its higher fin-ray counts, with 39–40 dorsal-fin rays and 26–27 anal-fin rays.

Playfair's two type specimens turned out to be two different species. Britz et al. (2024) designated the larger, 204 mm8 in SL fish illustrated in the original description as the lectotype, and identified the smaller one as C. gachua.

In the same study, DNA barcodes from fish identified as C. stewartii fell into two clades differing by 3.2–4.1%, and the authors called for a thorough revision of this group of snakeheads.

FishBase lists it as an obligate air-breather. All Channa species have a chamber above each gill, lined with respiratory tissue, that lets them breathe atmospheric air, so the fish must always be able to reach the surface.

The IUCN Red List assesses it as Least Concern (2010).[3]