Every species

Mastacembelus albomaculatus is a spiny eel endemic to Lake Tanganyika, where it inhabits rocky areas around the shoreline. Rarely seen in the hobby, it suits a Tanganyikan community of species too large to be considered food, and its hard, alkaline water requirements rule out most other freshwater tanks. The stiffened dorsal rays that give spiny eels their name mean care is needed when handling it.

The tyre-track eel, Mastacembelus armatus, is a spiny eel from South Asia and Myanmar, also known as the white-spotted spiny eel. Growing to around 91 cm, it hides during the day and often buries itself, so it needs sand, plenty of hiding places and a close-fitting hood. It eats live fish in the wild, and tankmates should be too large to be considered prey.

The Tanganyikan spiny eel, Mastacembelus ellipsifer, is a spiny eel endemic to Lake Tanganyika. It is found around the shores, most often where the rocks give way to sandier substrates, and spends much of its time burrowed in the substrate, so the aquarium needs a layer of sand. Nocturnal and predatory, it is best kept in a Tanganyikan community with species too large to be considered food.

The fire eel, Mastacembelus erythrotaenia, is a spiny eel recorded from Laos, Vietnam, Cambodia, Thailand, Malaysia and Indonesia. It usually inhabits sluggish lowland waters including floodplains and slow-moving rivers, and is also a food fish in its native countries. In the aquarium it hides away during the day and often buries itself, so it needs a sand substrate, plenty of cover and a close-fitting hood.

Mastacembelus plagiostomus is a spiny eel endemic to Lake Tanganyika, found in shallow water over rocky areas around the shoreline. Very rarely seen in the hobby, it suits a Tanganyikan community of species too large to be considered food and is somewhat territorial with conspecifics. It grows to 300 mm SL, and its stiffened dorsal rays call for care when handling it.

The Mayan cichlid, Mayaheros urophthalmus, is a large cichlid native to eastern parts of Mexico, Belize, Guatemala, Honduras and Nicaragua. Also known as the Mexican mojarra, it lives in swamps, marshes and coastal lagoons, can tolerate and even breed in full marine conditions, and is often seen spawning around mangroves. Territorial and fairly aggressive, it is regarded as a potential pest fish in the USA, where introduced populations exist. It is still often sold as Cichlasoma urophthalmus.

The cobalt blue zebra, Maylandia callainos, is an mbuna endemic to the north of Lake Malawi. Formerly Pseudotropheus callainos and Metriaclima callainos, it is still named as one of these by many sources and has been sold as Pseudotropheus zebra 'pearly'. It is very easily confused with similar species such as M. estherae and M. benetos. Aggressive and territorial, it can be combined with other mbuna but not with peaceful species such as peacocks or utaka.

The red zebra, Maylandia estherae, is a mbuna endemic to Lake Malawi, found along the Mozambique and Malawi coasts from Metangula to Gome. Only described as a distinct species in 1995, it was previously regarded as a morph of Maylandia zebra. Some males are blue and females orange, though orange and OB males occur depending on locality. Not especially aggressive for a mbuna, it will hybridise, so colour forms should never be kept together. It is still often sold as Pseudotropheus estherae.

The goldbreast zebra, Maylandia fainzilberi, is a large mbuna endemic to Lake Malawi, found on the north-western coast from Chirwa Island to Usisya and on the Tanzanian and Mozambican shores. It has also been grouped in Metriaclima and Pseudotropheus. It has extra rows of teeth, with the bicuspid rows extending unusually far back into the mouth. Growing to around 175 mm and one of the most aggressive and territorial mbuna, it is not a good species for the beginner.

The red top ice blue zebra, Maylandia greshakei, is an mbuna endemic to Lake Malawi, found only around Makokola in the southeast of the lake. It inhabits the upper parts of rocky reefs next to open water, leaving the reef to feed on phytoplankton. Formerly Pseudotropheus greshakei and Metriaclima greshakei, it is still named as either of these by many sources. Aggressive and territorial, it can be combined with other mbuna but not with peaceful species such as peacocks or utaka.

Known in the hobby as the kennyi, Maylandia lombardoi is a mbuna endemic to Lake Malawi, confined to the Mbenji Islands and Nkhomo Reef. In a reverse of the usual mbuna pattern, dominant males are yellow and females blue, though subdominant males often turn blue and brooding females can turn yellow. One of the most aggressive and territorial mbuna, it is not recommended for the novice, and commercially produced fish tend to be of lower quality than wild ones. It is still often sold as Pseudotropheus lombardoi.

The zebra mbuna, Maylandia zebra, is a cichlid endemic to Lake Malawi, where it inhabits rocky zones around shores, reefs and islands. One of the more aggressive mbuna, it is not a fish for a general community aquarium. It should be kept in a Malawi tank at around three females to each male.

Mchenga flavimanus is a peaceful utaka cichlid endemic to Lake Malawi, known from Nkhata Bay and the islands of Chitande, Mbowe and Kande. It shoals in large numbers in open water over sand and isolated boulders at 5 to 20 metres, feeding on zooplankton. Still listed as a Copadichromis in much of the literature, it suits a peaceful Lake Malawi community, but should not be kept with mbuna or with other Mchenga or Copadichromis, since they can hybridise.

The ornate tetra, Megalamphodus bentosi, is a small characid whose type locality lies on the main channel of the lower Amazon at Óbidos, Brazil. It is very similar to a number of congeners, some of them undescribed, and the rosy tetra is the one most often seen in the trade. It may also be sold as 'Bentos' tetra' or 'white-tipped tetra'. It mostly inhabits sluggish tributaries, side arms and forest lakes, often around submerged roots, branches or plants.

The serpae tetra, Megalamphodus eques, is a characid with an enormous range through much of the Amazon drainage and the Río Paraguay. Very common in the trade, it is also sold as the 'jewel', 'red minor', 'blood' or 'callistus' tetra, and ornamental strains include 'long-finned' and 'balloon' forms. It has a reputation for nipping the fins of tankmates, although this is most pronounced when too few are kept or space is limited.

The bleeding heart tetra, Megalamphodus erythrostigma, is a characid from the upper Amazon basin where the borders of Brazil, Peru and Colombia meet. The best-known of three similar species in the 'bleeding heart' subgroup, it has the reddish humeral spot found in no other characid. Generally peaceful, although adult males are territorial to an extent, it mostly inhabits sluggish tributaries, side arms and forest lakes.

The crystal red tetra, Megalamphodus haraldschultzi, is a small characid endemic to the rio Araguaia system in Brazil. It is occasionally available, usually as bycatch among shipments of other fishes, and is sometimes traded as 'Araguaia red' or 'Schultz's tetra'. It is most easily separated from the similar Megalamphodus eques by the dorsal-fin marking, which is less extensive and bordered above by a white blotch and below by a yellowish band.

The black phantom tetra, Megalamphodus megalopterus, is a characid from the upper rio Madeira and upper rio Paraguai in Bolivia and Brazil. Most records are from the rio Guaporé (Río Iténez in Bolivia). Popular in the hobby and bred commercially in several countries, it is also available as a 'long-finned' strain. Adult males have black fins with the pelvic, dorsal and anal enlarged, while females are deeper-bodied with reddish pelvic, anal and adipose fins.

The rosy tetra, Megalamphodus rosaceus, is a small characid from Guyana, Suriname and Brazil, in river systems including the Essequibo and Corantijn. It is so similar to Megalamphodus bentosi that it was once considered a subspecies of it, and is most easily told apart by lacking the dark marking just behind the operculum. The vast majority of fish in the trade are mass bred on commercial farms.

The lesser bleeding heart tetra, Megalamphodus socolofi, is a characid known only from the rio Negro basin and the rio Nhamundá in Brazil. One of three similar species in the 'bleeding heart' subgroup, it shares their reddish humeral spot, found in no other characid. Generally peaceful, although adult males are territorial to an extent, it mostly inhabits sluggish tributaries, side arms and forest lakes.