The Emperor Tetra (Nematobrycon palmeri) is a very attractive shoaling fish for the community aquarium.  Its distinctive coloration consists of a mostly cream-colored body that is highlighted by a thick horizontal black stripe and yellow edges along its fins.  Adult males also display a very noticeable purple sheen above their black stripe, especially when competing for the attention of females.  In addition, adult males have dramatically elongated dorsal and caudal fins, including an extended middle ray that creates a “trident” tail.  Females are generally smaller and thicker in size.  The Emperor Tetra typically breeds in pairs and must be kept…