Polyeunoa laevis is a scale worm which is widely distributed in the Southern Ocean and occurs over a wide depth range, from 35m to 2450m.

[2][3] Polyeunoa laevis has 75 segments, with 15 pairs of elytra.

the dorsum is covered with numerous dark brown cross lines on every segment that are especially dense anteriorly.

The lateral antennae inserted ventrally (beneath prostomium and median antenna).

[2][4] There is significant morphological and genetic diversity from different populations across P. laevis' range and it is possible that further research will result in this taxon being divided into several species.