Every species

The royal featherback, Chitala blanci, is a very large notopterid endemic to the Mekong drainage in Laos, Thailand, Vietnam and Cambodia. Also sold as the 'royal knifefish', it reaches 1200 mm SL and arguably has no place in the ornamental hobby, being suitable only for public installations or the very largest private aquaria. Many small dark spots on the front of the body merge into oblique stripes, and it is thought to be threatened by dam construction.

The Indian featherback, Chitala chitala, is a very large notopterid probably restricted to Pakistan, India, Nepal and Bangladesh. Its name has been widely misapplied in the trade, most often to the Southeast Asian C. ornata, but it is very rarely exported for aquaria and is fished and cultured for food in India. Growing to 1220 mm SL, it has non-ocellated black spots above the anal fin and is the only Chitala normally showing gold or silver bars on the back.

The giant featherback, Chitala lopis, is a notopterid accepted to range from the Mekong basin to Peninsular Malaysia, Sumatra, Borneo and Java. That range appears to require confirmation: it may already be extinct on Java, and the species may comprise several closely-related taxa. Older juveniles and adults lack the dark body markings of other Chitala and have a more pronounced jaw, and at up to 1500 mm SL it is suitable only for public installations or the very largest private aquaria.

The clown featherback, Chitala ornata, is a large notopterid native to the Mae Klong, Chao Phraya and Mekong river systems of Thailand and Indochina. Also traded as the 'clown knifefish', it has rows of large ocellated spots above the anal-fin base and is regularly misidentified as C. chitala. It grows to 1000 mm SL and arguably has no place in the ornamental hobby, yet it remains popular, with albino and leucistic forms line-bred for the purpose.

The desert goby, Chlamydogobius eremius, is a small goby endemic to the Lake Eyre drainage basin in South Australia. It does not occur in the salt lake itself but inhabits isolated freshwater springs, flowing artesian bores and ephemeral waterholes. Males are much more colourful than females but can change colour considerably, and they can be aggressive in spawning condition, so it is best maintained alone.

The golden puffer, Chonerhinos naritus, is a pufferfish from estuarine rivers in China, Myanmar, Thailand, Vietnam and Indonesia. Much of the available information describes it as a freshwater species, but it appears to be estuarine, and all museum specimens were collected in brackish or marine conditions, so it needs marine salt in aquaria. An aggressive, intolerant fish, it requires its own aquarium and can easily bite chunks from other fish.

Chromidotilapia guntheri is a mouthbrooding cichlid from coastal drainages of western Africa between Liberia and Cameroon, plus the Niger and Benue. It occurs in a number of geographic forms, with fish from Cameroon tending to show dark blotches on the dorsal fin. A benthophagous omnivore, it sifts mouthfuls of substrate for food, and the male broods the eggs while the female defends the surrounding territory.

The clown loach, Chromobotia macracanthus, is a large botiid loach native to river systems of Borneo and Sumatra in Indonesia. Widely sold, it is wholly unsuitable for smaller aquaria: a group needs a tank of at least 180 x 60 cm, and a properly kept fish can live for more than twenty years. Bornean and Sumatran populations differ slightly in pattern, and in the Batang Hari, Sumatra, drifting larvae are now collected and grown on for the trade.

The tucanare peacock bass, Cichla monoculus, is a large predatory cichlid from Colombia, French Guiana, Peru and Brazil, including the Rio Solimões. Often sold as small juveniles, it grows to around 80 cm and needs a tank of at least 10 x 3 x 4 feet as an adult, so it is more suited to public aquaria. It is territorial and moderately aggressive and will eat any tankmate small enough to be considered food.

The peacock bass, Cichla ocellaris, is a large predatory cichlid native to Colombia, Venezuela, Guyana, Suriname, French Guiana and Brazil. Introduced populations exist in several countries, including Singapore and the USA. Often sold as small juveniles, it grows to around 75 cm and needs a tank of at least 10 x 3 x 4 feet as an adult, and it will eat any tankmate small enough to be considered food.

The Orinoco peacock bass, Cichla orinocensis, is a predatory cichlid from the Orinoco basin in Venezuela and Colombia and the Rio Negro in Brazil. One of the smaller peacock bass, it still grows to around 60 cm and needs a tank of at least 8 x 3 x 3 feet as an adult. It is territorial and moderately aggressive and will eat any tankmate small enough to be considered food.

The speckled pavon, Cichla temensis, is a large peacock bass from the Rio Negro, Uatumã and Orinoco basins in Colombia, Venezuela, Guyana and Brazil. One of the largest Cichla species at up to 99 cm, it is more suited to public aquaria and needs a tank of at least 10 x 3 x 4 feet as an adult. Often sold as small juveniles, it is also fished as a sport fish.

The Bolivia cichlid, Cichlasoma boliviense, is a cichlid from the Rio Mamoré, Rio Guaporé and Madre de Dios drainages of Bolivia and Peru. It lives in shallow pools and along slow-moving shorelines and grows to around 11 cm. Not commonly seen in the hobby, it is less aggressive than many Central American cichlids but suits only a community of medium to large fish, and it rearranges the decor to suit itself.

The chisel-tooth cichlid, Cincelichthys bocourti, is a Central American cichlid from Lake Izabal and other Atlantic drainages of Guatemala and Belize. Described in 1902, it did not appear in the trade until wild fish were collected by American aquarists in 1994. Males reach at least 30 cm, and it is aggressive and territorial, so tankmates need choosing with care in a very large tank.

Cincelichthys pearsei is a large, almost exclusively vegetarian cichlid from the coastal waters of eastern Mexico and Guatemala. Males reach around 42.5 cm and females around 35 cm, so a fully grown male or pair needs a tank of around 240 cm, and any plants will be eaten. For its size it is quite placid, and suits a community of bigger fish that share its need for hard, alkaline water.

The walking catfish, Clarias batrachus, is a large air-breathing catfish. In the strict sense it is known only from Java, and the walking catfishes of mainland Asia belong to other species. It can move across land on its stiff pectoral spines provided it stays damp, so a tightly fitting cover is essential. Walking catfishes are highly predatory and tolerate a very wide range of conditions, and they have become pests in several countries where they were introduced for farming, most notably the southern US. Most fish in the trade are albino or leucistic aquarium variants.

The widehead catfish, Clarotes laticeps, is a large predatory catfish recorded across much of Africa, from Senegal and Guinea east to Egypt and Kenya. It inhabits large lakes and rivers and grows to 80 cm, though it is unlikely to reach this in captivity. Uncommon in the trade, it is capable of swallowing surprisingly large prey and is unsuitable for all but the biggest aquaria.

The keyhole cichlid, Cleithracara maronii, is a small cichlid from French Guiana, Guyana, Suriname, the Orinoco delta in Venezuela and Trinidad. It is told apart from relatives by the keyhole-shaped marking on each side of the body, and is one of few fishes whose generic name derives from its aquarium common name. It inhabits slow-moving blackwater streams, is naturally shy and sensitive to deteriorating water quality, and most fish on sale are commercially farmed.

The Congo barb, Clypeobarbus congicus, is a small African cyprinid from the Congo River drainage in the Republic of Congo and DR Congo. Rare in the hobby, it often turns out to be something else when it appears on exporters' lists. Its genus is characterised by a midlateral row of greatly enlarged, shield-like scales. A shoaling species with a distinct pecking order between males, it should be kept in a group of 8 or more in a well-planted tank.

Iksookimia hugowolfeldi is a cobitid loach endemic to Korea, known from the Yeongsan and Tamjin river systems in the province of Jeollanam-do. It is most similar to I. longicorpus, of which it was first considered a geographical variant, and has narrow dark bars below the lateral line with densely arranged small spots above. It apparently prefers small, shallow rivers and streams with moderate to fast currents, and needs clean, well-oxygenated water.