Paracetonurus flagellicauda is a species of fish in the subfamily Macrourinae (grenadiers or rattails).

[3][4] Some sources place it in the genus Pseudonezumia.

[5][6] Paracetonurus flagellicauda has a slender body, tapering to a string-like tail (hence its specific name flagellicauda, "whip-tail").

[2] Paracetonurus flagellicauda lives in the northeast Atlantic Ocean and southwest Indian Ocean, and is common in the Azores.

The species may migrate along the mid-ocean ridges to travel between oceans.