Hydrolycus armatus is a species of dogtooth characin found in freshwater of tropical South America. The biara ("Rhaphiodon vulpinus") is a South American piscivorous fish in the dogtooth characin family. The pike characin feeds on bony fish. Hoplias australis is a predatory freshwater characin fish of the southern Neotropics. Characidium fasciatum, the darter characin, is a fish in the family "Characidae". Attonitus is a genus of characin endemic to Peru. The Pike characin (Acestrorhynchus microlepis) is a species of fish in the family Acestrorhynchidae. Thrissobrycon pectinifer is a species of characin endemic to Brazil. Hypobrycon is a genus of characin found in the Uruguay River basin in South America. "Axelrodia", a genus of characin from South America, is named for him. Hemigrammus bleheri is a species of characin found in Amazon Basin in Brazil and Peru. Moenkhausia lepidura is a species of characin found in the Amazon and Orinoco River basins.