The most common of all arowana found on sale, and also the largest topping out at around at 24-30 inches. They need very long and wide tanks as they have a large turning circle and suffer from disorders such as drop eye and gill curl if not cared for properly. These fish really need large tropical ponds and can be kept with similar sized peaceful yet robust mid-bottom dwelling fish. The arowana is almost entirely top dwelling and perfectly capable of smashing through a flimsy tank lid! They will also eat smaller tank mates.
The clown knifefish is a very popular knifefish because it is extremely attractive. They usually have a pattern of large spots, but this can be quite variable and it seems that no two clown knifefish are exactly alike. Its fin undulates, allowing it to move either forwards or backwards, making it a very graceful swimmer. This is a very large carnivore fish and it can sometimes be extremely aggressive towards other fish and is best kept alone or with other large fish like oscars or similar sized oddballs like the silver arowana.
These are popular and the most commonly seen of the knifefish and sold when quite small. Don't let that fool you. These guys should get at least 30 cm. They are nocturnal predators but have quite a small mouth and are peaceful towards larger tank mates. They can also be quite shy so should not be kept with boisterous fish nor with suckermouth fish which may suck on the knifefish's flanks. It is recommend that one BGK is kept to a tank, as they will bully and dominate one another. They should work fine in a spacious tank with plenty of hiding places.
Because of their toughness, spotted gars are easy to keep in the home aquarium. But be warned: properly fed young gar grow quickly and can reach a foot or so within the first year. They like a well planted setup, as they come from areas thick with aquatic weeds. Giving them a lot of cover also helps them feel secure, which in turn can deter them from freaking out and slamming into the sides of the tank and possibly injuring themselves. These are not aggressive fish, but could only be kept with other large fish that can stand up for themselves. Obviously small fish would just be eaten.
It is a large, very attractive, deep bodied aquarium fish. Its coloration is a golden body contrasted with bold black bands. It can reach up to 18 inches in length, though in the aquarium they generally only get 9 to 12 inches. They can be fussy about the water quality; an excellent filtration system is a must. They will need open swimming spaces and the sexes should be kept on an equal ratio. These fish are just as happy in a planted set up with wood or rocks to provide hiding places or in an open set up with little added to the aquarium. The siamese tiger fish is classed as a carnivorous species and as such should never be housed with smaller tank mates.
A popular and stunning looking eel-like fish. This fish gets quite large, usually around 12-24 inches in captivity! It is also a predator and should therefore only be housed with larger robust yet peaceful mid-top dwelling fish, smaller fish will be eaten. They often will not tolerate others of their own kind or similar species as they mature however. They should be provided with hiding places - PVC pipe is popular with these fish.
They are fascinating, very primitive, nocturnal, predatory fishes that will obtain lengths of up to 65 cm in the home aquarium, and lifespans exceeding 25 years. The best substrate for these fish is sand, with plenty of hiding-spots, and sturdy plants. A secure, weighted top is essential when keeping these fish, as their frequent breaching for air, and occasional jumps put them at high risk of leaving the aquarium. Be aware that as predators, no fish small enough to fit into the mouths of ornate bichirs are safe tankmates.
One of the smaller of the Snakehead species. The Rainbow Snakehead works well in a community tank with larger robust species, it must be noted that smaller fish may well become food! It won't be very tolerating towards other Snakeheads either. You must make sure you have a secure tank if you consider one of these as they are excellent escape artists!