Biology/Natural History: Female amphipods, such as this one, brood their eggs and young on a ventral thoracic brood pouch formed by flaplike inner branches of the legs 3-5 called oostegites. The oostegites can be seen in the photo above as a second set of flaps behind the large flaplike coxae of the legs. This female was carrying at least 11 young in an advanced stage of development.

Peramphithoe and the closely related Amphithoe are common on kelp and eelgrass.