FAMILY Rhamphichthyidae Regan, 1911 - sand knifefishes GENUS Gymnorhamphichthys Ellis, in Eigenmann, 1912 - sand knifefishes [=Urumara] Species Gymnorhamphichthys bogardusae Lundberg, 2005 - Orinoco sand knifefish Species Gymnorhamphichthys britskii Carvalho et al., 2011 - La Plata sand knifefish Species Gymnorhamphichthys hypostomus Ellis, in Eigenmann, 1912 - Mamore sand knifefish Species Gymnorhamphichthys rondoni (Miranda Ribeiro, 1920) - Rondon's sand knifefish [=petiti] Species Gymnorhamphichthys rosamariae Schawssmann, 1989 - Rosa Maria sand knifefish GENUS Hypopygus Hoedeman, 1962 - sand knifefishes [=Stegostenopos] Species Hypopygus benoneae Peixoto et al., 2013 - Melgaco sand knifefish Species Hypopygus cryptogenes (Triques, 1997) - Igarape sand knifefish Species Hypopygus hoedemani de Santana & Crampton, 2011 - Preto de Eva sand knifefish Species Hypopygus isbruckeri de Santana & Crampton, 2011 - Cano Magua sand knifefish Species Hypopygus lepturus Hoedeman, 1962 - Maroni sand knifefish Species Hypopygus minissimus de Santana & Crampton, 2011 - Cano Viejita sand knifefish Species Hypopygus neblinae Mago-Leccia, 1994 - Rio Baria sand knifefish Species Hypopygus nijsseni de Santana & Crampton, 2011 - Tefe sand knifefish Species Hypopygus ortegai de Santana & Crampton, 2011 - Loreto sand knifefish GENUS Iracema Triques, 1996 - sand knifefishes Species Iracema caiana Triques, 1996 - Jauaperi sand knifefish GENUS Rhamphichthys Müller & Troschel, 1849 - sand knifefishes [=Altona] Species Rhamphichthys apurensis (Fernández-Yépez, 1968) - Apure sand knifefish Species Rhamphichthys atlanticus Triques, 1999 - Viana sand knifefish Species Rhamphichthys drepanium Triques, 1999 - Janauari sand knifefish Species Rhamphichthys hahni (Meinken, 1937) - Hahn's sand knifefish Species Rhamphichthys heleios Carvalho & Albert, 2015 - Solimoes sand knifefish Species Rhamphichthys lineatus Castelnau, 1855 - lined sand knifefish Species Rhamphichthys longior Triques, 1999 - Paru sand knifefish Species Rhamphichthys pantherinus Castelnau, 1855 - Ucayali sand knifefish [=marmoratus] Species Rhamphichthys rostratus (Linnaeus, 1766) - rostrate sand knifefish [=blochii, longirostratus, reinhardti, schneideri, schomburgki] GENUS Steatogenys Boulenger, 1898 - sand knifefishes [=Tateichthys] Species Steatogenys duidae (La Monte, 1929) - Mt. Duida sand knifefish Species Steatogenys elegans (Steindachner, 1880) - Rio Negro sand knifefish [=mirabilis] Species Steatogenys ocellatus Crampton et al., 2004 - Rio Bare sand knifefish