Alestopetersius

The cherry red Congo tetra, Alestopetersius brichardi, is an alestid from the middle Congo and tributaries such as the Busira and Ruki in DR Congo. It has also been sold under the misapplied names A. nigropterus and A. ansorgii. Adult males develop extended median caudal-fin rays, with a broad dark lateral stripe running from behind the eye to their tip, and the species is lively and somewhat skittish but generally peaceful.

The yellow-tailed Congo tetra, Alestopetersius caudalis, is an alestid from the lower Congo region, recorded upriver as far as the Irebu channel. Also traded as the 'yellow-finned', 'yellowtail' or 'blue Congo' tetra, it is occasionally bred commercially, though not on the scale of its better-known relative Phenacogrammus interruptus. Adult males develop extended median caudal-fin rays, and the narrow dark lateral stripe broadens markedly on the caudal fin.

The African rainbow tetra is an alestid from the Congo River system around Kinshasa, DR Congo, normally traded as Alestopetersius nigropterus. Neither that name nor A. cf. ansorgii, the other it is sold under, appears to be correct: the true A. nigropterus is endemic to Lake Mai-Ndombe and little or not exported, and A. ansorgii is a synonym of Nannopetersius ansorgii. Lively and somewhat skittish but generally peaceful, it suits a larger community aquarium.

The blue diamond tetra, Alestopetersius smykalai, is an alestid from the Imo and Niger drainages in Nigeria. The only member of its genus found outside the Congo system, it has a prominent dark, roughly diamond-shaped marking on the caudal peduncle, and adult males lack extended median caudal-fin rays. Very rare in the hobby, it is considered Vulnerable by the IUCN because of rainforest loss, dams and habitat degradation in the Niger delta.