Megalamphodus

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.

The red phantom tetra, Megalamphodus sweglesi, is a small characid endemic to the upper and middle Río Orinoco watershed in Colombia and Venezuela. It apparently favours minor tributaries, oxbows and flooded forests, and in Venezuela is often found in morichals. Bred commercially in several countries, it has been traded in more than one colour form, and Zarske (2014) concluded that the particularly red form sold as 'red' or 'var. rubra' is conspecific.