Order Cyprinodontiformes
Suborder Cyprinodontoidei
Family Poeciliidae
Subfamily Poeciliinae
Genus Brachyrhaphis
Fish of the genus Brachyrhaphis are not so simple as pets. Therefore, it is better not to introduce them into a community aquarium. They feel better with a small addition of salt: 2-3 teaspoons per 50 liters of water. Reproduction is complicated because females behave very aggressively towards partners (which means there must be many males!), and in addition, most parents turn out to be cannibals later.
— Brachyrhaphis cascajalensis [Meek & Hildebrand, 1913]. Synonym: Gambusia cascajalensis. Costa Rica, Panama, Cascajal and Portobelo rivers. Male 6 cm, female 7 cm. Olive-gray with a dark reticulated pattern formed by dark scale edges. The male has a yellow-black dorsal fin and a black gonopodium. Belly and eyes are silvery. Fins are yellow. Aquarium with dense vegetation, including plants floating on the surface.
It is recommended to keep them in a group with a significant majority of males. The aquarium should be covered with a glass lid to prevent the fish from jumping out. Fish stay in the upper and middle water layers. They feel better with a small addition of salt (2 teaspoons per 50 liters). Sexual maturity occurs at 5-7 months. After 24-30 days, the female gives birth to 20-40 fry measuring 7 mm. T 24-27°C, salinity 3-5%.
— Brachyrhaphis episcopi [Steindachner, 1878]. Synonym: Gambusia episcopi, latipunctata, Priapichthys episcopi. English: Bishop Livebearer, The Bishop. Panama. Male 3 cm, female 5 cm. Yellow coloration, a series of dark burgundy spots along the sides, a dark spot at the base of the anal fin, belly is silvery-white. Dorsal and caudal fins are small, orange-brown.
The aquarium should be quite large and densely planted with live plants. Females behave very aggressively towards partners, so there should be more males. They occupy the upper water layers and therefore go well together with bottom-dwelling fish. The fish are very sensitive to sudden changes in water parameters. Filtration and weekly water changes are mandatory. They are very susceptible to all types of diseases. Every 4-5 weeks, 20 to 30 fry are born. T 24-28°C; pH 6-7.5.
— Brachyrhaphis hartwegi [Rosen & Bailey, 1963]. English: Soconusco Gambusia. Mexico, Guatemala. Male 3.5 cm, female 5 cm. Yellow coloration with barely visible dark vertical bars. Juveniles have brightly glowing eyes. The fish prefer to stay in the upper and middle water layers. pH 7.0-7.5; dH 5°; T 24-26°C.
— Brachyrhaphis holdridgei [Bussing, 1967]. Guatemala. 5 cm. Olive-gray coloration with a pink or orange tint, scales with a crescent-shaped edge, with 10-12 dark dashes and 3-4 black spots. Dorsal fin is red-orange with black stripes. Anal fin is elongated. Dorsal fin rays are long and almost reach the base of the caudal fin. Caudal fin is dark, with a series of short vertical dark bars slightly closer to the base of the tail. When keeping several pairs, only one dominant male will be bright and beautiful, while in a large group there will be several brightly colored males, and the rest will remain pale. Females are also somewhat aggressive. T 21-30°C.
Identification: Genus Brachyrhaphis
Brachyrhaphis olomina, roseni, roswithae, terrabensis.
Alfaro cultratus, Alfaro huberi. 
