Order Characiformes
Family Characidae (American Tetras)
Subfamily Cheirodontinae
Genus Amazonspinther.
— Amazonian tetra — Amazonspinther dalmata [Buhrnheim, Carvalho, Malabarba & Weitzman, 2008]. Brazil, Amazon River. 2 cm. A miniature fish with a very attractive appearance. A greenish, metallic yellow iridescent line runs along the dorsal ridge. The body is translucent, with a black spot at the bases of the caudal, dorsal, and anal fins. Caudal peduncle is elongated.
Genus Nanocheirodon.
— Nanocheirodon — Nanocheirodon insignis [Steindachner, 1880]. Synonym: Chirodon insignis. South America, Venezuela. 3 cm. In males, the tips of the pelvic fins are white. At the base of the caudal fin, there is a black spot with white dots along its edges; in females, these are yellowish. Females have white stripes on the caudal fin and a blotch at the tail base. Males feature elongated pelvic and caudal fins. Both have a white border on the median fins. In the aquarium, it swims in the middle water layers. Males establish and defend small territories among plants. T 22-26°C; pH 5.6-7.6; dH 2-14°.
Genus Odontostilbe.
Also kept: — Odontostilbe microcephala (Eigenmann & Ogle, 1907). 3.5 cm. A triangular spot at the base of the tail. Dorsal and anal fins are orange; — Odontostilbe pequira (Steindachner, 1882). 5 cm. A dark blotch on the tip of the dorsal fin, as well as at the base of the tail and on the caudal fin.
— Odontostilbe paraguayensis [Eigenmann & Kennedy, 1903]. (Eng: Three Spotted Tetra). Paraguay. 3.5 cm. Olive-colored with a black-and-gold line extending from the top of the operculum to the caudal peduncle. A triangular spot is located at the base of the tail. The caudal fin is yellowish. The male is more slender with a curved anal fin. Keep in a school of 6 or more individuals. Very sensitive to nitrates and water cleanliness. T 24-27°C; dH up to 15°; pH 6.0-7.2.
Genus Serrapinnus.
— Serrapinnus kriegi [Schindler, 1937]. Paraguay. 3.5 cm. Olive-colored with a black-and-gold line running from the top of the operculum to the tail base. A triangular spot sits at the base of the tail. Caudal fin is yellowish. The male is more slender with a curved anal fin. Keep in a school of 6 or more individuals. Highly sensitive to nitrates and water cleanliness. T 24-27°C; dH up to 15°; pH 6.0-7.2.
— Serrapinnus micropterus [Eigenmann, 1910]. Synonym: Cheirodon micropterus, Odontostilbe madeirae. From the upper Paraguay River to the São Francisco River. 5 cm. Olive-colored with a black-and-gold stripe from the top of the operculum to the tail base. Base of the tail has a black spot bordered by white. The male is slimmer, with a curved anal fin. Undemanding species in terms of maintenance. Water temperature 20-25°C.
— Piaba tetra — Serrapinnus piaba [Lutken, 1875]. Synonym: Cheirodon, Chirodon piaba, calliurus, jaguariensis. Brazil. 3 cm. Triangular spot at the base of the caudal fin. Caudal fin is yellowish. Olive-colored with a black-and-gold line extending from the upper gill cover to the base of the tail. Tail base with a black spot edged in white. Water temperature 20-25°C; dH 4-5°; pH 6.5.
Iguanodectes spilurus, Rhoadsia altipinna, Tetragonopterus argenteus.
Aphyocharax erythrurus, Aphyocharax paraguayensis, Aphyocharax rathbuni. 
