After Froese & Pauly, 2001 ["The FishBase"]

<==o Eptatretus [Bdellostoma, Polistoderma] [Fishbase: 31]
   |-- E. atami (Dean, 1904) (Brown hagfish)
   |-- E. bischoffii (Schneider, 1880)
   |-- E. burgeri (Girard, 1855) (Inshore hagfish)
   |-- E. caribbeaus Fernholm, 1982
   |-- E. carlhubbsi McMillan & Wisner, 1984
   |-- E. chinensis Kuo & Mok, 1994
   |-- E. cirrhatus (Forster, 1801)
   |-- E. deani (Evermann & Goldsborough, 1907) (Black hagfish)
   |-- E. fritzi Wisner & McMillan, 1990
   |-- E. goliath Mincarone & Stewart, 2006 (goliath hagfish)
   |-- E. hexatrema (Müller, 1836) (Sixgill hagfish)
   |-- E. indrambaryai Wongratana, 1983
   |-- E. laurahubbsae McMillan & Wisner, 1984
   |-- E. longipinnis Strahan, 1975
   |-- E. lopheliae Fernholm & Quattrini, 2008
   |-- E. mcconnaugheyi Wisner & McMillan, 1990
   |-- E. mendozai Hensley, 1985
   |-- E. minor Fernholm & Hubbs, 1981
   |-- E. multidens Fernholm & Hubbs, 1981
   |-- E. nanii Wisner & McMillan, 1988
   |-- E. octatrema (Barnard, 1923) (Eightgill hagfish)
   |-- E. okinoseanus (Dean, 1904)
   |-- E. polytrema (Girard, 1855) (Fourteen-gill hagfish)
   |-- E. sinus Wisner & McMillan, 1990
   |-- E. springeri (Bigelow & Schroeder, 1952) (Gulf hagfish)
   |-- E. stoutii (Lockington, 1878) (Pacific hagfish)
   |-- E. strahani McMillan & Wisner, 1984
   |-- E. wisneri (Kuo, Huang & Mok , 1994)
   |?-o Quadratus Wisner, 1999 [= Eptatretus (Fernholm, 1998)]
   |  |-- Q. nelsoni (Kuo, Huang & Mok, 1994) [Paramyxine nelsoni Kuo, Huang & Mok, 1994]
   |  |-- Q. taiwanae (Shen & Tao, 1975) [Eptatretus taiwanae (Shen & Tao, 1975)]
   |  |-- Q. yangi (Teng, 1958) [Eptatretus yangi (Teng, 1958)]
   |  `-- Q. ancon Mok, Saavedra-Diaz & Acero P., 2001
   `--o “five-gilled hagfishes”
      |-- E. eos Fernholm, 1991
      |-- E. grouseri McMillan, 1999
      |-- E. lakeside Mincarone & McCosker, 2004
      |-- E. profundus (Barnard, 1923) (Five-gill hagfish)
      |-- E. wayuu Mok, Saavedra-Diaz & Acero P., 2001
      `?-o Paramyxine [= Eptatretus (Fernholm, 1998)]
         |-- P. cheni Shen & Tao, 1975
         |-- P. fernholmi Kuo, Huang & Mok, 1994
         `-- P. sheni Kuo, Huang & Mok, 1994

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