Every species

The sturgeon catfish, Lamontichthys filamentosus, is a loricariid from the central and western Amazon in Brazil, Peru, Ecuador and Bolivia. Above 60 mm SL the pectoral-fin spine extends into a filament that can be over four times the length of the first branched ray, and the dorsal-fin spine carries a similar extension. Relatively common in the hobby but not easy to maintain, it needs clean, well-oxygenated water and a mature aquarium with plenty of algae-covered surfaces.

Lamontichthys llanero is a suckermouth catfish from the Orinoco basin in Venezuela. It lives among rocky substrates and driftwood snags in shallow, flowing water, and needs well-oxygenated water with plenty of movement. Unaggressive and peaceful with conspecifics, it is rarely seen in the hobby.

The Congo lamprologus, Lamprologus congoensis, is a cichlid from fast-moving stretches of the Congo River in the Republic of Congo and DR Congo. It resembles Steatocranus species in shape and lifestyle, with a streamlined body, strong pectoral fins and a much-reduced swimbladder that makes it less buoyant. Aggressive and territorial, it should not be kept with other cichlids. It spawns polygamously in caves, and males develop a prominent nuchal hump.

Lasiancistrus tentaculatus (L092, L194) is a suckermouth catfish from Colombia and Venezuela that lives among driftwood snags in rivers. Hobbyists describe it as a wood eater and it should be given plenty of wood, although no study has looked at its diet. Mature males develop a few Ancistrus-like tentacles around the mouth, the only species in the genus to do so. Sunken eyes and a belly that is not rounded are classic signs of emaciation in newly imported fish.

The Tanganyika lates, Lates angustifrons, is a giant predatory fish endemic to Lake Tanganyika, growing to 200 cm. Juveniles have turned up in some aquatic stores, but the species is not suited to captive life in any respect, and housing an adult is beyond the reach of most public aquaria. Highly piscivorous, it feeds mainly on cichlids in nature, and adults live throughout the lake, usually around the lake bed.

The barramundi, Lates calcarifer, is a large predatory fish found from the Persian Gulf east through Asia and south to Australia, reaching 200 cm. It lives in fresh, brackish and marine coastal waters, and is diadromous, migrating to brackish or marine water to spawn. All individuals begin life as males before some change sex. Juveniles turn up in some aquatic stores, but it is not suited to captive life in any respect, and it is a prized food fish in many of its native countries.

The Nile perch, Lates niloticus, is a giant predatory fish from Central and Western Africa, reaching 193 cm and up to 200 kg. Introduced into many African countries as a food fish, it is thought to have contributed to the extinction of over 200 endemic species in Lake Victoria, and the IUCN lists it among the world's top 100 invasive species. Juveniles turn up in some aquatic stores, but it is not suited to captive life in any respect.

The flying minnow, Laubuka caeruleostigmata, is a cyprinid from the Mekong system in Laos, Thailand and Cambodia, and the Chao Phraya and Mae Klong. Also known as 'leaping barb', it was once quite common in the ornamental trade and has apparently become scarce in the wild. It schools near the surface in main river channels, has a bright blue spot on top of the head, and is an accomplished jumper that needs a tightly-fitting cover.

The Malabar hatchet chela, Laubuka fasciata, is a cyprinid endemic to the state of Kerala in southwestern India. A dark stripe runs from the eye to the caudal peduncle, and it favours slow-moving, shallow margins of rivers and streams over rock and gravel. It is occasionally available in the aquarium trade, apparently collected only in small numbers, and is an accomplished jumper.

The Indian glass barb, Laubuka laubuca, is a cyprinid probably endemic to the Ganges-Brahmaputra system in northern India, Bangladesh and Nepal. Traditionally considered to occur across the Indian subcontinent and most of Southeast Asia, it appears to be far more restricted, and many fish in the trade are probably L. siamensis. L. laubuca has a roundish, ocellated humeral spot and a thin, less conspicuous stripe interrupted by vertical markings. Other names include 'Indian hatchet fish' and 'winged danio'.

Laubuka siamensis is a cyprinid from the Mekong, the Chao Phraya and Mae Klong in Thailand, and smaller drainages south to Peninsular Malaysia. Long considered synonymous with L. laubuca, it seems likely to be the species behind many of the fish entering the trade under that name. A conspicuous dark stripe, iridescent blue in life, runs uninterrupted along the rear of the body to an oval blotch on the caudal peduncle. It swims in groups at or just below the surface and is an accomplished jumper.

The marbled pim, Leiarius longibarbis, is a large pimelodid catfish from the Rio Orinoco, Rio Essequibo and Amazon basins. It grows to around 80 cm and can live for well over 20 years, and whether it should be considered an aquarium subject at all is debatable. Much of the literature still lists it as L. marmoratus, a name treated as a junior synonym since a reclassification in 2003.

The sailfin pim, Leiarius pictus, is a large pimelodid catfish from the Rio Orinoco basin in Colombia and Venezuela and the Amazon in Peru and Brazil. Also known as the painted, saddle or marbled sailfin catfish, it reaches around 60 cm and can live for well over 20 years. Juveniles are often sold without adequate information on their long-term care, and a fully-grown fish needs a tank in the region of 240 by 90 by 120 cm.

Lepidiolamprologus boulengeri is a small shell-dwelling cichlid endemic to Lake Tanganyika, found along the Tanzanian shoreline in the north of the lake. It lives among scattered rocks and open sand littered with empty snail shells. It is told apart from L. hecqui and Lamprologus kungweensis by the orange border on its dorsal and anal fins, and it will spawn in small caves if no shells are available.

Lepidocephalichthys annandalei is a cobitid loach from the mid-to-lower Ganges and Brahmaputra systems in Nepal, Bangladesh and north-east India. Rarely traded, it has been sold as L. sp. 'peacock', presumably for its caudal-fin pattern of two dark v-shaped markings, unique within the genus. Fish in the trade differ slightly from the original description, in particular lacking a notched caudal fin.

Lepidocephalichthys berdmorei is a cobitid loach found across Myanmar, Thailand, Laos, north-eastern India and Bangladesh. One of the most frequently-traded members of the genus, it is an excellent choice for those new to keeping loaches. Unlike most congeners it shows a preference for headwaters and streams with clear, flowing water, and its larger adult size separates it from the similar L. thermalis.

The Loktak loach, Lepidocephalichthys irrorata, is a small cobitid from north-eastern India and Bangladesh. Hora described it as widely distributed in lakes and streams of the Manipur Valley, and some of his specimens came from Loktak Lake. It grows to only 29 mm SL, has large, exposed scales on top of the head, and is occasionally exported as bycatch among other species.

Lepidocephalichthys furcatus is a small cobitid loach from Peninsular Malaysia, southern Thailand and North Sumatra, Indonesia. Not traded often, it turns up occasionally as bycatch among shipments of other species. It is told apart from congeners most easily by the prominent, roughly semi-circular lamina circularis in males, a feature unique within the genus, and it has a forked caudal fin.

Lepidocephalichthys goalparensis is a cobitid loach from the Brahmaputra, Ganges and upper Irrawaddy basins in India, Nepal, Bangladesh and Myanmar. Rarely seen in the hobby, it was imported into the UK in late 2011 as bycatch among mastacembelid eels from northern India, and the identification was confirmed by Justin Havird. The forked caudal fin normally carries four or five broad, dark V-shaped bars.

Lepidocephalichthys guntea is a cobitid loach from the Ganges and Brahmaputra systems of northern India, Nepal and Bangladesh, and much of Myanmar. One of the most frequently-traded members of the group, it is an excellent choice for those new to keeping loaches. Males carry a solid, dark lateral stripe and females spotted flanks, and patterning varies with origin. It is also used as a food fish, eaten fresh and dried.