Every species

Caelatoglanis zonatus is an erethistid catfish known only from the Ataran River system in Kayin state, Myanmar, part of the Salween drainage. Images of the Ataran show flowing, forest-shaded headwaters with clear water, a mixed sand and rock substrate and plenty of submerged driftwood and leaf litter. The name zonatus refers to its barred colour pattern.

The big-eyed mouthbrooder, Callochromis macrops, is a sand-sifting cichlid endemic to Lake Tanganyika, found in the southern part of the lake. It lives over shallow sandy bottoms near rocks, taking in mouthfuls of sand and sifting out invertebrates through the gills. Several geographical colour forms exist and should not be kept together, as they hybridise freely. Males are particularly belligerent towards one another in captivity, so a small tank suits one male with several females.

The worm-jawed mormyrid, Campylomormyrus tamandua, is a benthic mormyrid recorded from nine countries in West and Central Africa. It sometimes arrives among imports of the elephant fish, Gnathonemus petersii, but has both jaws extended into a beak-like shape. It needs pristine soft, acidic water, generally refuses standard foods and grows to 400 mm SL. Like other mormyrids it produces a weak electric field, used to navigate and to communicate.

The moose-faced loach, Canthophrys gongota, is a cobitid loach from the Ganges and Brahmaputra river systems in Nepal, northern India and Bangladesh. Often referred to as Somileptes gongota in aquarium literature, it is rarely seen in the trade, being notoriously delicate and difficult to ship. It mostly inhabits slow-moving, shallow tributaries and minor rivers over mud, sand or gravel.

Carinotetraodon borneensis is a small red-eyed puffer known only from southern Sarawak, Malaysia (Borneo), in the Sarawak, Sadong and Rajang rivers. Uncommon in the hobby, it is sometimes mixed among shipments of C. salivator, which has distinct dark bars on the head and body in both sexes. Males in particular tend to be territorial, but a group can be kept where there is enough cover and space.

The red-tailed redeye puffer, Carinotetraodon irrubesco, is a small freshwater puffer endemic to Indonesia, known from Sumatra and West Kalimantan. Males have a reddish caudal fin and lack the black spot at the dorsal-fin base seen in the other red-eyed puffers, and the eyes bulge clearly above the head. It has been collected only among submerged riparian vegetation of terrestrial origin, in murky brown water.

The redeye puffer, Carinotetraodon lorteti, is a small freshwater puffer from the lower Mekong basin and the Chao Phraya watershed in Indochina. It inhabits slow-moving to standing water in shady forest streams, minor tributaries and floodplains, often among dense vegetation. It tends to bite the fins of tankmates and is territorially aggressive, so is best kept alone, though a group can be kept with enough space and a suitable layout.

Carinotetraodon salivator is a small red-eyed puffer known only from Sarawak, Borneo, in the Lupar, Sarawak and Rajang river systems. Sometimes traded as the 'striped redeye puffer' or 'zebra puffer', it has distinct dark bars on the head and body in both sexes, a colour pattern unique within the genus. Unlike most congeners, there is evidence that it prefers flowing water.

The dwarf puffer, Carinotetraodon travancoricus, is a tiny freshwater puffer endemic to the state of Kerala in southern India. Also known as the Malabar puffer and probably the smallest species of puffer, it usually inhabits sluggish, heavily vegetated inland waters. A popular import, it is often sold without the information needed for its long-term care, and tends to nip the fins of slow-moving or long-finned fish.

The blackwing hatchetfish, Carnegiella marthae, is a small freshwater hatchetfish from the upper Orinoco in Venezuela and the rio Negro in Brazil. It appears to be a stenotypic inhabitant of blackwater, found in igapó and igarapé habitats with overhanging vegetation and leaf litter. Very peaceful but small and timid, it is best kept in a group of 10 or more with similarly sized, peaceful fishes.

The pygmy hatchetfish, Carnegiella myersi, is a tiny freshwater hatchetfish from the Peruvian Amazon basin, with a second population in Bolivia. The smallest and most delicate of the nominal hatchetfishes, it has a shallower, rounded keel that gives it an elongate profile. It lives in small, shaded, shallow forest streams and must be kept in a group of at least six, away from active tankmates.

The marbled hatchetfish, Carnegiella strigata, is a hatchetfish from the Amazon and Orinoco basins and coastal rivers of Guyana and Suriname. Popular in the hobby, it is collected for the trade mostly in the rio Negro basin in Brazil. Its larger size and dark, marbled pattern set it apart from congeners, though the pattern varies and the wide range may be open to question. It appears to live only in blackwater.

The wimpel piranha, Catoprion mento, is a scale-eating fish from Colombia, Venezuela, Guyana, Brazil and Bolivia. Though not a true piranha, it resembles them and is quite closely related to Pygocentrus species. The common name comes from the German 'Wimpel' (banner), after the extensions to the leading dorsal-fin rays in mature fish. Adults are best housed alone, and it is sensitive to poor water quality and to swings in chemistry.

The false SAE, Garra cambodgiensis, is a cyprinid from the Mekong, Chao Phraya and Mae Klong basins and northern Peninsular Malaysia. It is still traded as Garra taeniata and is often confused with the Crossocheilus species sold as 'Siamese algae eater'. In this species the dark lateral stripe ends at the caudal peduncle, and a sucker formed by the lower lip is present. It inhabits swiftly-flowing headwaters and tributaries.

Garra fasciacauda is a cyprinid native to the Mekong river system in Thailand, Laos, Vietnam and Cambodia, including the Tonlé Sap basin. It has a black submarginal stripe on both caudal lobes and a plain dorsal fin. It inhabits swiftly-flowing water and migrates seasonally, with many fish moving from the Tonlé Sap system to the Khone Falls in the dry season.

The blue whale catfish, Cetopsis coecutiens, is a cetopsid catfish from the Amazon, Tocantins and Orinoco river basins. In the wild it swims in voracious feeding groups, homing in on weakened fish by smell and burrowing into prey. It will bite chunks out of tankmates much bigger than itself, so it is best kept alone, and at up to 26.5 cm it needs a large tank with strong water flow and dim lighting.

The chocolate frogmouth catfish, Chaca bankanensis, is an ambush predator from rainforest waters in Malaysia, Indonesia and Brunei. It lies hidden among leaf litter and mulm, using its barbels as a lure to draw prey within reach of its capacious mouth. Very similar to C. chaca, it is darker and redder and lacks the hooklets on the lips and body. Chaca species appear to lower the pH in confined conditions, so water quality needs close attention.

The frogmouth catfish, Chaca chaca, is an ambush predator from still and slow-moving waters in India, Nepal, Bangladesh and Indonesia. Also known as the angler catfish, it lies hidden among leaf litter and mulm and moves its barbels like a worm to lure prey, which can be almost as big as itself. It is usually lighter than C. bankanensis and has small hooklets on the lower lip and body that its relative lacks.

The striped bulldog pleco, Chaetostoma formosae, is a suckermouth catfish from piedmont streams of the upper Meta and Guaviare systems in Colombia. The commonest member of the genus in the hobby, it is still misidentified as C. thompsoni and sold under several names and L-numbers. An obligate inhabitant of fast-flowing headwater streams, it needs clean, well-oxygenated water with strong flow and does best in a dedicated species set-up.

The spotted bulldog plec, Chaetostoma sp. 'L187a', is a rubbernose plec from fast-flowing mountain streams in Colombia. One of the more commonly seen Chaetostoma, its true identity is uncertain and it is sometimes misidentified in shops. It needs clear, cool, well-oxygenated water with plenty of movement, and it is territorial with its own kind unless each fish has a rock of its own.