n = 4
| Scientific Name | Author | Valid Name | Family | English Name |
|---|---|---|---|---|
| Pythonichthys asodes | Rosenblatt & Rubinoff, 1972 | Pythonichthys asodes | Heterenchelyidae | Pacific mud eel |
| Pythonichthys macrurus | (Regan, 1912) | Pythonichthys macrurus | Heterenchelyidae | Longtailed shortfaced eel |
| Pythonichthys microphthalmus | (Regan, 1912) | Pythonichthys microphthalmus | Heterenchelyidae | Shorttailed shortfaced eel |
| Pythonichthys sanguineus | Poey, 1868 | Pythonichthys sanguineus | Heterenchelyidae |