Dr Heok Hee Ng reminds us that although these are natural predators, a few snakehead species can become acceptable community fish.
Any discussion of predatory oddball fish for the aquarium will invariably feature a snakehead or two. They have been thrust into the limelight because of the picture painted of them as an aquatic invasive species but, whatever your opinion, snakeheads make great aquarium fish if given proper care.
They earn their name because their flattened shape and the scales on their heads are reminiscent of the large epidermal scales on snakes.
Snakeheads are members of the family Channidae, a group of perciform (perch-like) fishes whose affinities are unknown, although recent studies on the molecular phylogeny of bony fishes consider snakeheads as most closely related to the labyrinth fishes (anabantoids) and the synbranchiform eels, which include the spiny eels.
These fish are naturally distributed from south-eastern Iran and eastern Afghanistan eastwards to China, northwards to Siberia and southwards to Java, and from the White Nile westwards to the Senegal and Chad river drainages and southwards to the Congo river drainage in Africa.
There are two genera (Channa, Parachanna) containing 34 species (31 Channa and three Parachanna), although the diversity is much greater and several undescribed species, particularly from India — for example, Channa sp. 'lal cheng' and Channa sp. 'Kerala five stripe' — have already reached the aquarium trade.
One unusual feature is the snakeheads' tolerance of low oxygen levels. They are primarily able to do so because of their paired suprabranchial chambers which are lined with respiratory epithelia (skin modified to absorb atmospheric oxygen) enabling them to use atmospheric oxygen as sub-adults and adults.
Snakeheads are in fact obligatory air breathers and must have air lest they drown. If you find the concept of a drowning fish strange, remember that snakeheads are not the only obligatory air breathers. Many fish with a similar biology, such as walking catfishes and even the pirarucu (Arapaima), will drown if they do not surface.
There’s a common misconception that air-breathing fish live in stagnant, relatively foul water in the wild and that clean water conditions are therefore not necessary in the aquarium. While some snakeheads can tolerate a wide range of water conditions — and studies have shown that the Dwarf, Spotted and Chevron can survive for at least 72 hours in pH levels from 4.3 to 9.4 — many fare poorly when water conditions are allowed to deteriorate or undergo rapid changes, as in a massive water change.
Many snakeheads come from habitats where water is soft (to 8 GH) and slightly acidic to neutral (pH 5.0 to 7.0), and these values represent a suitable guide to successful maintenance.
Snakeheads are fairly undemanding as regards tank décor. They are not active swimmers and, when not feeding, tend to move only when surfacing for air. They spend a lot of time hovering in midwater or resting on the bottom within cover as ambush predators. Ample hiding spaces in the form of driftwood and submerged vegetation should therefore be provided. Surface cover, created by floating plants, is also recommended.
Snakeheads are also capable of some powerful bursts of acceleration and apt to knock things around in the tank or stir up substrate. For this reason gravel, not fine sand, should be the substrate of choice in any snakehead tank. Otherwise the constant stirring of finer particles will clog filters.
Bearing in mind the propensity for snakeheads to drown when denied access to the surface, remember to leave enough room for air when filling your tank.
Note too that snakeheads are fantastic leapers and while it may be fun to test the survival abilities of your fish should it decide to leave, a tight-fitting cover is vital.
Snakeheads also have a deserved reputation as voracious carnivores and one would think that in the aquarium could only be fed live food. However, many aquarists find they can be weaned on to meaty foods such as chunks of fish and sinking meaty pellets.
With such a highly carnivorous nature you may also believe that snakeheads are not suitable for the community tank but, if heeding a few warnings, some make good community fish.
Consider first the size of species and many dwarf species behave well enough to become community fish. Another concern is the size of tank mates. Obviously, maintaining a school of Neon tetras with snakeheads is too much of a risk, so they should always be kept with fishes too large to be considered food.
For many medium-sized snakeheads in the 30-40cm/12-16” range, tank mates should ideally be relatively fast swimming and robust fish. Many medium-sized to large cyprinids are therefore ideal.
Despite their predatory nature, smaller snakeheads are retiring in nature, so can suffer at the hands of large, aggressive cichlids.
Snakeheads also display considerable changes in colour pattern when growing. Many juveniles are more attractively marked than adults, frequently featuring a bright yellow to orange-red stripe running the length of the body. This pattern quickly disappears with age and many species assume a browner, more drab look. This sometimes leads to aquarists losing interest in the fish as it grows, so those considering their first purchase of very young snakeheads should be well aware of what they are getting into.
The price of love is not cheap
Price is no object for true snakehead lovers, with mark-ups for rare specimens rivaling those of dragonfish. The Barca snakehead (Channa barca) pictured above, became one of the most expensive aquarium fish when the first individuals imported into the UK were going at £5,000 apiece. The price has since dropped to about £1,500, as seen at Aquarama 2009 in Singapore, but that’s still a hefty outlay!
Which species is best for me?
Golden cobra snakehead (Channa aurantimaculata)
Also known as the Orange-spotted snakehead, the Golden cobra reaches about 40cm/16”. This is a relatively aggressive fish that’s best kept alone.
Coming from northern Assam in India, this species is best kept at cooler temperatures around 20-26°C/68-79°F. Water should ideally be pH 6.0–7.0 and GH 10.
Red snakehead (Channa micropeltes)
This is also known as the Giant snakehead for a good reason.Capable of 1m/39” or more, even in captivity, it is the largest snakehead species. An extremely large tank is therefore necessary to house an adult giant snakehead.
Reds are also among the most aggressive snakeheads and will attack many tank mates, including conspecifics, even if they are larger or if the snakehead is not hungry. They also have the largest teeth of all snakeheads and will use them on humans.
Although juveniles have an attractive colour pattern of a bright orange stripe running the length of the body, this rapidly fades with age and adults are a duller blue.
Reds are not too demanding of water conditions and can be maintained in 26–28°C/79-82°F water of most acidities and hardness, as long as extremes are avoided. This is a species only for the experienced fishkeeper.
Dwarf snakehead (Channa gachua)
One of the most wide-ranging snakeheads, it is generally acknowledged that members identified as the Dwarf belong to a complex of several species. Some ichthyologists have acknowledged this diversity by referring to the South-East Asian populations as a distinct species (C. limbata).
The Dwarf snakehead, especially those from northern India, should be maintained in cooler water of 18–25°C/64-77°F with more middle-of-the-road water parameters (pH 6.0–7.5, GH 6 to 8) being ideal. Reaching only 20cm/7.8”, the Dwarf is relatively docile and can be maintained in a community tank with other fishes of similar size.
Emperor snakehead (Channa marulioides)
The Emperor is capable of reaching 65cm/26”, rendering it suitable only for the species tank, or at very best with other large tank mates — although a very large tank would be needed anyway!
This fish is best kept in water at 24-28°C/75-82°F, pH 6.0-7.0 and GH to 10.
Rainbow snakehead (Channa bleheri)
This is a small, relatively peaceful member of the dwarf snakehead complex. The Rainbow is among the most colourful of all snakeheads and reaching about 20cm/7.8” is as suited for the community tank as the Dwarf — and, like the Dwarf, the Rainbow will be best kept at cooler temperatures.
Banka snakehead (Channa bankanensis)
This is probably the most demanding snakehead in terms of water conditions.
The Banka hails from blackwater habitats that are extremely acidic (pH to 2.8) and while it is not necessary to maintain the fish at such high acidities, pH should be kept low (6.0 and below) as too high a level will make them prone to infections.
This species also does better in tannins/humic acids, so peat in the filtration would be good.
Despite growing to only 23cm/9” the Banka is aggressive and best kept in a species tank.
Splendid snakehead (Channa lucius)
Capable of reaching to 40cm/15.7”, the Splendid is one of the larger species and care should be tailored accordingly. This fairly aggressive species should only be kept with large, robust tank mates — if at all. Water should ideally be 24-28°C/75-82°F, pH 5.0–6.5 and GH to 8.
Ocellated snakehead (Channa pleurophthalma)
One of the more attractive South-East Asian species, the Ocellated differs in shape from other snakeheads in having a more laterally compressed body. Others have almost cylindrical bodies.
In the wild, the Ocellated is typically found in brown water habitats of slightly higher acidities than usual (pH 5.0-5.6), but this species readily acclimatises to pH ranges closer to neutral (6.0–7.0) in the aquarium. This species should be maintained in 24-28°C/75-82°F water that is not too hard (to 8 GH).
The Ocellated is a relatively peaceful species that can be kept with large, robust tank mates in a fairly large tank as this species reaches 45cm/18”.
Spotted snakehead (Channa punctata)
Native to India, the Spotted is a common species inhabiting an extensive range of habitats, from mild temperate to tropical. Because of this range, this species is reported to tolerate a very broad range of temperatures from 9-40°C/48-104°F.
Experiments have also shown that it can tolerate a large pH range, so water conditions are not too important as long as extremes are avoided. A relatively small species that reaches to 30cm/12”, the Spotted snakehead is nevertheless aggressive enough for only large, robust tank mates to be considered.
Chevron snakehead (Channa striata)
The Chevron is one of the most robust freshwater fishes and consequently, water parameters are not important, although the usual caveat of avoiding extremes still applies. This is a large species that can reach 90cm/35” and, like the Red, is ill-suited for the beginner aquarist.
African snakehead (Parachanna obscura)
Although it superficially resembles the Splendid in shape and colour, the African can be distinguished by its long and prominent tubular nostrils. Reaching to 45cm/18”, water parameters for this species should be similar to the Splendid, although this is reportedly a more docile species.
What can I keep with them?
Some snakeheads — for example, Golden cobra and Emperor — are best kept alone and should never be in the same tank, even with large tank mates.
Smaller to medium-sized species (Dwarf and Ocellated) can be kept with medium to large-sized cyprinids, similar-sized robust catfishes (such as some doradids and/or loricariids), cichlids not overtly aggressive, such as severums (Heros severus) and Tiger perches (Datnioides spp.).
What foods, besides live fish and shrimp, will snakeheads readily eat?
Snakeheads can be weaned off live foods and have been known to readily take chunks of fish, mussels, shrimps for human consumption, and commercial pelleted foods of the meaty kind — such as sinking pellets or even commercial fish pellets such as trout chow.
Other non-aquatic live foods that can be fed wth confidence include earthworms, mealworms and crickets. Younger snakeheads will readily take bloodworms and krill.
How do I spawn them?
Snakeheads can be relatively easy to spawn, provided the right conditions are set up for them. Sexing most species is not easy for the beginner, although the truism that females are plumper is readily applicable here.
Given the difficulty in sexing fish, it is sometimes necessary to introduce several fish in the same tank in order to let them pair up naturally (make sure the tank is large enough to house several comfortably, and provide ample hiding spaces to reduce aggression).
Some do not require a strong trigger to breed, while others require a period of cooling, followed by a rise in temperature to simulate changing of seasons. Some brood their eggs orally while others utilise bubble nests.
Both parents typically guard the fry (which swim in a compact school) once the eggs hatch.
This item first appeared in the Christmas 2009 issue of Practical Fishkeeping magazine. It may not be reproduced without written permission.