Channa aurantimaculata MUSIKASINTHORN, 2000

Orange-spotted Snakehead

Etymology

Channa: from the Latin channe, used to refer to an unspecified species of sea perch.

aurantimaculata: from the Latin aurantium, meaning ‘orange’, and maculatus, meaning ‘stained, spotted’, in reference to this species’ colour pattern.

Classification

Order: Perciformes Family: Channidae

Distribution

Endemic to the Brahmaputra River basin in the states of Assam and Arunachal Pradesh, northeastern India.

It’s apparently restricted to the northern portion of Assam while in Arunachal Pradesh it’s been collected in the vicinity of Tezu in Lohit district, although the full extent of its distribution is unclear.

Type locality is ‘Market at Dibrugarh town, Dibrugarh, Assam, India’.

Habitat

The area in which it lives has a ‘tropical monsoon rainforest’ climate characterised by heavy rainfall, high humidity and hot summer temperatures.

In his description Musikasinthorn (2000) suggested it to inhabit ‘forest streams, swamps, and ponds connected with the Brahmaputra River’, based on information from local collectors, before suggesting it may be restricted to the discontinuous patches of rainforest which remain in northern Assam.

Goswami et al. (2006) report that it constructs burrows close to tree stumps in forested areas which are temporarily inundated during the annual monsoons.

These burrows may be up to 200 cm in depth and the fish use them as refuges during the dry winter months, emerging to hunt and breed while the habitat is flooded.

Since it is less of an ecological generalist than many Channa species, requires a specific type of microhabitat, has a restricted range and is never found in large numbers it is recommended as a concern for conservation by Goswami et al., 2006., who also noted that it is ‘rampantly fished’ for food and the ornamental trade.

Like others in the genus it can tolerate hypoxic conditions due to its ability to breath atmospheric air (see ‘Notes’).

Maximum Standard Length

350 – 400 mm.

Aquarium SizeTop ↑

An aquarium with base measuring at least 150 ∗ 60 cm is recommended.

Water depth is less important but should not be less than 30 cm.

Maintenance

Prefers a dimly-lit aquarium with a layer of surface vegetation such as Ceratopteris spp. plus some submerged cover.

It’s essential to use a tightly-fitting hood since Channa spp. are notorious for their ability to escape, and a gap should be left between this and the water surface as they require access to a layer of humid air.

More importantly still C. aurantimaculata must not be maintained at a constant temperature but provided with natural seasonal variation in the form of defined winter and summer periods.

During the colder period the fish do not require much food and the water level can be allowed to fall without additional top-ups.

Water Conditions

Temperature: 10 – 28 °C

pH: 6.0 – 8.0

Hardness: 36 – 357 ppm

Diet

An obligate predator which probably feeds on smaller fishes and insects in nature but in most cases adapts well to dead alternatives in captivity.

Some specimens even accept dried foods though these should never form the staple diet.

Young fish can be offered chironomid larvae (bloodworm), small earthworms, chopped prawn and suchlike while adults will accept strips of fish flesh, whole prawns/shrimp, mussels, live river shrimp, larger earthworms, etc.

This species should not be fed mammalian or avian meat such as beef heart or chicken since some of the lipids contained in these cannot be properly metabolised by the fish and may cause excess fat deposits and even organ degeneration.

Similarly there is no benefit in the use of ‘feeder’ fish such as livebearers or small goldfish which carry with them the risk of parasite or disease introduction and at any rate tend not have a high nutritional value unless properly conditioned beforehand.

Behaviour and CompatibilityTop ↑

Best-maintained in a species-specific aquarium.

It is aggressively territorial towards conspecifics and violence can occur suddenly and without warning even in pairs or groups which have been maintained together for extended periods of time.

Sexual Dimorphism

Males begin to develop a more-extended, intensely-patterned dorsal-fin once they reach a size of around 150 mm.

In most cases adult fish can also be sexed by viewing them from above since females have a broader head shape.

Reproduction

A paternal mouthbrooder which has been bred infrequently in aquaria.

NotesTop ↑

This species is also traded as ‘golden cobra snakehead’ and is available in the aquarium trade on a regular basis.

It can be distinguished from other Channa species by the following combination of characters: 51-54 lateral line scales; 45-47 dorsal-fin rays; 28-30 anal-fin rays; 8-12 cheek scales; 50-52 total vertebrae; two large cycloid scales on each side of lower jaw undersurface; pelvic-fin length less than 50 % of pectoral-fin length; upper half of body dark brown to black with 7-8 large, irregular orange blotches; pectoral-fin with a black blotch at the base and 5 broad blackish bands.

Members of the family Channidae are commonly referred to as ‘snakeheads’ due to possession of large scales on the head of most species which are reminiscent of the epidermal scales (cephalic plates) on the heads of snakes.

There currently exist over 30 valid species but diversity within the group is likely to prove significantly greater.

The existence of distinct phylogenetic groups has been proposed with the putative C. gachua species assemblage of Britz (2008) containing C. orientalis, C. gachua, C. bleheri, C. burmanica, C. barca, C. aurantimaculata, and C. stewartii.

Species from northeastern India have also been divided into the C. marulius and C. gachua groups (Vishwanath and Geetakumari, 2009).

C. aurantimaculata should be included in the latter assemblage which the authors characterise by possessing the following combination of characters: presence of a U-shaped isthmus; cephalic sensory pores evenly arranged in a single row; presence of one or two large cycloid scales on each side of the lower jaw; absence of a sharp prominent spine-like hypurapophysis; absence or presence of one tooth plate in the epibranchial; absence of an elongated urostyle.

All Channa spp. possess supplementary breathing apparatus in the form of paired suprabranchial chambers located behind and above the gills, although these are not labyrinthic but lined with respiratory epithelium.

These chambers allow the fish to breathe atmospheric air and survive in hypoxic conditions or even out of the water for a considerable period of time, and in aquaria they are often seen rising to the surface to take gulps of air.

References

1. Musikasinthorn, P., 2000 - Ichthyological Research 47(1): 27-37
   Channa aurantimaculata, a new channid fish from Assam (Brahmaputra River basin), India, with designation of a neotype for C. amphibeus (McClelland, 1845).
2. Brede, N. and P. Antler, 2009 - Natur und Tier Verlag, Münster: 62 pp.
   Schlangenkopffische—Die Gattungen Channa und Parachanna.
3. Britz, R., 2008 - Ichthyological Exploration of Freshwaters 8(4) [for 2007]: 335-344
   Channa ornatipinnis and C. pulchra, two new species of dwarf snakeheads from Myanmar (Teleostei: Channidae).
4. Goswami, M. M., B. Arunav and P. Janardan, 2006 - Journal of the Inland Fisheries Society of India 38(1): 1-8
   Comparative biometry, habitat structure and distribution of endemic snakehead (Teleostei: Channidae) species of Assam, India.
5. Vishwanath, W. and Kh. Geetakumari, 2009 - Journal of Threatened Taxa 1(2): 97-105
   Diagnosis and interrelationships of fishes of the genus Channa Scopoli (Teleostei: Channidae) of northeastern India.