Every species

L147 is an undescribed Ancistomus species, a suckermouth catfish from tributaries of the middle Río Orinoco in Venezuela and the lower Río Meta in Colombia. Some reports suggest it occurs further up the Meta system, around Villavicencio, some 600 km upriver. It spawns in caves with the male responsible for brood care, and has been bred regularly in aquaria.

The big spot peckoltia (L163) is an undescribed suckermouth catfish collected from the Rio Pará in the Brazilian Amazon. Trade fish are often confused with the very similar L013, and the two are only easily told apart as they mature: L163 keeps its spotted pattern while L013 tends to become duller. It is placed in the genus Ancistomus. Newly imported fish should have a rounded belly and eyes that are not sunken.

Ancistrus claro, the gold marble bristlenose catfish (LDA 008), is a suckermouth catfish from the rios Claro and Coxipó in Mato Grosso, Brazil. It inhabits flowing streams over boulders and bedrock. Sometimes confused with unidentified fishes such as A. sp. 'L352', it has long maxillary barbels and small spots on the head, with vermiform lines on the body in males and spots all over in females. A peaceful cave-spawner, it has been bred in aquaria on numerous occasions.

Ancistrus dolichopterus, the starlight ancistrus (L183), is a bristlenose catfish most likely endemic to the middle and lower rio Negro, Brazil. It inhabits blackwater streams. The name has been used for the common bristlenose and other similar species, while this fish has been called A. hoplogenys, and much of the literature confuses them. It differs from all congeners in having 9 soft dorsal-fin rays, and is territorial with conspecifics and similarly-shaped species.

Ancistrus ranunculus, the medusa pleco (L034), is a wide-headed, flattened suckermouth catfish from the rio Xingu and rio Tocantins basins in Brazil. It lives among rocks in shallow, fast-flowing water, needs well-oxygenated water with plenty of movement and a protein-rich diet, and is often in poor condition after import. Juveniles carry light spots like the similarly shaped L255, but in A. ranunculus these fade as the fish matures.

L255, the spotted medusa plec, is a wide-headed, flattened Ancistrus known only from the middle rio Xingu basin in Pará state, Brazil. It lives among rocks in shallow, fast-flowing water, needs well-oxygenated water with plenty of movement and a protein-rich diet, and is often in poor condition after import. It resembles A. ranunculus, but keeps its light body markings throughout life, whereas those of A. ranunculus fade as the fish matures.

The common bristlenose catfish, Ancistrus sp. '3', is the loricariid sold everywhere as the 'bristlenose', of unknown origin and bred commercially. It was once thought close to the Argentinian A. cirrhosus, but genetic data suggests otherwise, and some consider it a hybrid. Adult males carry fleshy tentacles on the head, and the species spawns in caves with the male guarding the brood.

The horned bristlenose pleco, Ancistrus triradiatus, is a small suckermouth catfish from Colombia and Venezuela, found among rocks in flowing streams. It is often confused with the common bristlenose, Ancistrus sp. (3), and other congeners, and some are so similar that a definite identification needs the collection locality. Imported fish are almost always wild-caught. Mainly vegetarian and peaceful, it is easy to breed once mature.

The blue acara, Andinoacara pulcher, is a cichlid native to Trinidad and Tobago and parts of Venezuela. It occupies a variety of habitats, from murky still waters to clear streams. A mainstay of the hobby for many years, it is one of the easiest substrate-spawning cichlids to breed. Captive breeding has narrowed the gene pool, so most fish in the hobby are pale imitations of wild ones, and some are hybrids with related species. It was previously known as 'Aequidens' pulcher.

The green terror cichlid, Andinoacara rivulatus, is a large cichlid from extreme northern Peru and the coastal drainages of western Ecuador. Generally aggressive and territorial, it is best kept alone or as a mated pair unless the tank is enormous. Males grow substantially larger than females and develop a nuchal hump when mature. Fish from the northern end of its range may represent a different species.

Andinoacara sp. 'Orinoco' is an apparently undescribed cichlid from unspecified localities in the Río Orinoco basin, presumably in Venezuela. It was traded as 'Aequidens' sp. 'Orinoco' and, following Musilová et al. (2009), appears to be a member of Andinoacara. Relatively peaceful for a cichlid of its size, it is a biparental substrate spawner and relatively simple to breed.

Annamia cf. thuathienensis is a hillstream loach described from the Bô River in Thua Thien-Hue Province, central Vietnam. Its description was published in Vietnamese and very little is known about it: some major resources do not list it as valid, and Kottelat (2012) considers it a 'species inquirenda'. Its ecology should be similar to that of A. normani, which lives in riffles and rapids over rocky substrates.

The Vietnamese giraffe loach, Annamia normani, is a hillstream loach from Mekong tributaries in Vietnam, Laos and Cambodia and from coastal Vietnam. An obligate resident of riffles and rapids, it has been traded as the 'Vietnamese lizard loach' and 'Vietnamese Homaloptera'. Adults studied in the Duc My River were specialised grazers of cyanobacteria. Many of its known habitats are threatened by planned hydroelectric projects.

The African butterfly cichlid, Anomalochromis thomasi, is a dwarf cichlid from forest streams in Sierra Leone, Guinea and Liberia. Juveniles can look a little dull on sale, but it is peaceful, relatively undemanding and easily bred, and one of the best choices for the newcomer to dwarf cichlids. The genus is monotypic, although several colour forms are available from time to time and some may prove to be distinct species.

The striped headstander, Anostomus anostomus, is an anostomid from the Amazon and Orinoco river systems in Peru, Brazil, Venezuela and Guyana. It lives along rocky shores of fast-flowing rivers, grazing algae and small invertebrates from the rocks. Although it shoals in nature, it is very quarrelsome with conspecifics when only a few are kept, so it is best kept singly or in a group of 6 or more in a larger tank.

The gold-striped headstander, Anostomus ternetzi, is an anostomid from the Río Orinoco system and coastal Guyana, Suriname and French Guiana. It lives in rocky areas at the edge of fast-flowing rivers and streams, grazing algae and small invertebrates. Like A. anostomus, it is quarrelsome with conspecifics when only a few are kept. Its distribution in Brazil is unclear, with patchy records from the Araguaia and Xingu basins.

The Arabian toothcarp, Aphaniops dispar, is found around the coasts of the Red Sea and the Gulf of Aden. Inland populations also exist, and it tolerates anything from pure freshwater to hypersaline conditions. A 2003 phylogenetic study found it paraphyletic, and several populations once included in it have since been described as separate species, so forms are labelled by locality, such as 'Lake Assal'.

The Azraq toothcarp, Aphaniops sirhani, is endemic to what remains of Azraq Oasis in the Wadi Sirhan valley of the Syrian Desert, Jordan. From the 1960s the aquifers feeding the oasis were pumped to supply Amman, and the IUCN considers it critically endangered. Vigorous spawning behaviour makes it a poor choice for the community aquarium, and the emphasis is on captive reproduction.

The Mediterranean toothcarp, Aphanius fasciatus, occurs around much of the Mediterranean coast, from France and the Adriatic to Syria and Egypt. It mostly inhabits shallow lagoons, salt marshes and first order streams, and tolerates anything from freshwater to hypersaline conditions. Populations differ in colour and pattern but relatively little genetically, the exception being the isolated population in Lake Bafa, Turkey.

The red fin thresher plec, Aphanotorulus emarginatus, is a suckermouth catfish from the Amazon region of Brazil, Ecuador, Peru and Bolivia. Many geographical variants exist, four of them assigned L-numbers (L011, L035, L108 and L116), and all share the elongated caudal fin that gives the fish its common name. Often sold at 3-4" as Hypostomus cf. emarginata, it grows to around 40 cm and needs a spacious tank with well-oxygenated, flowing water.