Black Phantom Tetra (Hyphessobrycon megalopterus)

Males and females diverge visibly here, males run a taller, more dramatic dorsal fin they flare at rivals during dominance displays, essentially a miniature betta-style standoff that never escalates past posturing. The dark, smoky body color reads best against a paler substrate where the translucency actually shows. A calm schooler that's easy to sex once you know what to look for.

Care level: Easy · Temperament: Peaceful, shoaling · Max size: ~1.75" · Min tank: 15 gal · Diet: Omnivore, flake/micro-pellet