Female body asymmetrically oval. Pereion segments distinct, pereiopods small. Female pleonal segments may show a greater fusion than in species of the genus Bopyrus and appears distinct on one side only. The female has only 3 or 4 (not 5) pairs of uniramous pleopods, the most posterior of which may be represented only as small swellings. Male pleotelson with the segments fused; uropods presence
Female 1.7 mm, male 0.7 mm.
In the branchial cavity of prawns, typically in Hippolyte varians .
Recorded from southwest England, Channel Islands, western Ireland and the French coast.