Clausidium vancouverense, the red copepod, is a symbiont of the ghost shrimp Neotrypaea californiensis.

[1] It is one of six species in the genus Clausidium and is found with its host in the Pacific Ocean from Alaska to Baja California.

[3] Several features separate this copepod from other species in its genus.

Copepod distribution of a similar species Clausidium dissimile on ghost shrimp were positively correlated to the host's body size,[4] but host sex did not affect distribution.

[5] C. vancouverense sticks to the branchial cavity of its host via suckers.