Order Characiformes
Family Alestidae or African Tetras
Genus Alestopetersius
— Yellow-tailed Congo Tetra, Blue Congo Tetra, Yellow Fin Tetra, Yellow Tailed African Tetra, Yellowfin Congo Tetra, Yellowtail Congo Tetra — Alestopetersius caudalis [Boulenger, 1899]. Synonym: Petersius caudalis, brumpti, xenurus, Micralestes grandi, Hemigrammopetersius caudalis. Congo River basin. 7 cm. Body elongated, moderately high, compressed laterally. Dorsal fin high.
The body of the male is transparent, yellowish-gray with greenish, bluish, and golden iridescence, adorned with elongated unpaired filamentous fins edged with pearly white along the outer rays. Soft tones and semitones blend into one another, creating a unique color palette. The backs of the males glow with a blue neon light, and behind the gill cover, there is a bright emerald crescent-shaped spot.
Fins are yellowish. Dorsal fin is falcate and tall. Caudal fin is orange, the middle rays of the caudal fin can be slightly elongated, awl-shaped, up to 2 cm long, with a black longitudinal stripe in a white border running down the middle. While the Congo P. interruptus has multiple filamentous extensions, H. caudalis has only one. However, this black arrow separating the orange lobes of the tail looks very spectacular. During the courtship dances typical of males, all this fin splendor is spread out, and color intensity increases. Males are colored much brighter; the tips of the pelvic fins are white in the male and transparent in the female. The female’s body is transparent, yellowish-gray.
Peaceful, schooling, active, timid fish that stay in the upper and middle water layers. Can be kept in a community aquarium with dense planting in places and floating plants creating shaded areas, while still leaving enough swimming space. To prevent the fish from becoming timid, a group of 5 or more specimens should be kept. Difficult to maintain, delicate species, easily goes into shock. May eat plants.
Very thermophilic, temperature not less than 23°C. The beauty of the fish with its delicate fins is best revealed only in softly mineralized water with low nitrate content. Food: live food, crustaceans, phantom larvae, bloodworms, tubifex, and substitutes (they love taking insects from the water surface). The fish readily accept food in the water column and pick it from the bottom. Not a fish for beginner aquarists, quite capricious during acclimatization. pH 6.0-7.0; dH 4-10°; T 23-27°C.
— Blue Diamond Characin (Tetra) — Alestopetersius smykalai. Synonym: Hemigrammopetersius, Rhabdalestes smykalai. Nigeria. 9 cm. Iris is red. Males are silvery with a blue sheen. A black spot is present at the base of the tail. Dorsal fin is elongated. Females are gray-silvery; like the males, they have a black spot on the caudal peduncle, and their fins are transparent without patterns.
Peaceful, schooling, active fish that stay in the upper and middle water layers. Can be kept in a community aquarium with dense planting in places and floating plants creating shaded areas, while leaving enough swimming space.
Keep in a school of 6 or more individuals. Males vigorously chase females during spawning, so hiding places are essential. Weekly water changes of at least 20% are important, as the fish are very sensitive to biological pollutants and prefer fresh water. High water temperatures should be avoided. pH 6.0-7.2; T 23-26°C; dH 8-15°.
— Super Red Congo Tetra — Alestopetersius nigropterus [Poll, 1967]. Synonym: Hemigrammopetersius nigropterus. Congo, Lake Leopold II. 6 cm. Body silvery with red and gold tones. Just above the lateral line, they may show an iridescent blue color. Lateral line is yellow with orange tones. A dark spot is located behind the gill cover.
All fins are orange at the base and yellow at the edges with a black margin. The dorsal fin has blue at the tip, and the adipose fin is scarlet. The dorsal and caudal fins of males are elongated. The anal fin of this species is quite distinctive, ending at the base of the caudal peduncle. There is a completely red color morph (Super-Red Congo Tetra).
Peaceful fish, ideal for a community aquarium with similar species. An active fish that requires sufficient swimming space. Aquarium with marginal vegetation, floating plants, driftwood, and rocks for design and hiding spots. Should be kept in groups of 6-10 specimens. Males periodically conflict with each other. Occupies the middle and upper water layers.
They love good water circulation. If the water does not meet standards, the fish’s fins become frayed and tattered, and their beautiful coloration is lost. Prefer live food, but accept dry and frozen food; it is better to feed several times a day in small portions. pH 6.0-7.5; dH 3-18°; T 23-28°C.
Identification: Genus Alestopetersius.
Brycinus imberi, longipinnis, nurse.
Genus Lepidarchus, Genus Micralestes. 
