Brachyrhaphis roseni, commonly known as the cardinal brachy, is a poeciliid fish from Central America.

The fish have a slightly arched body and twelve dark vertical stripes, which are normally more prominent in males.

[2] Brachyrhaphis roseni lives in stagnant and slow to moderately fast flowing waters.

[2] At lower elevations the temperature is higher, the flow is slower, and the substrate consists of sand, gravel, and mud, whereas at higher elevations the water is cooler and faster and runs over small stones and medium to large boulders.

[7] One habitat, a creek by the Pan-American Highway near the border with Costa Rica–Panama border, is composed of large boulders, and there B. roseni stays in the shallow waters along with Rivulus hildebrandi; the deeper waters are inhabited by Poecilia gillii, a Curimata species, an Astyanax species, and certain cichlids, which are larger and dominate B.