Nematobrycon palmeri is a small characid widely known as Emperor Tetra in the aquarium trade. This species is endemic to the Atrato and San Juan River basins in Colombia, where inhabits backwater and ponds with aquatic vegetation (Weitzman anf Fink, 1971; Lima et al., 2003). It is largely appreciated by its iridescent greenish blue color contrasting with a broad black lateral stripe and yellowish fins. The males present interesting sexual dimorphism associated to the elongation of the dorsal-, pelvic-, anal, and caudal-fin rays. Although this species is well know by aquarists, very little information is available about its feeding habit, behavior and life cycle in the wild.