Rhizocephalan parasites have a peculiar life cycle, and their adults lost almost all traits found usually in Crustacea. Despite some data on anatomy and ultrastructure of interna of Peltogastridae, some crucial aspects of morphology are still unknown.

The hairy hermit crab Pagurus hirsutiusculus was sampled from the low intertidal at two sites in Auke Bay, southeastern Alaska (58 degrees 22'N 134 degrees 40'W) to examine the prevalence of rhizocephalan parasitism. One site was exposed to wave activity

Rhizocephalan parasites have a peculiar life cycle, and their adults lost almost all traits found usually in Crustacea. Despite some data on anatomy and ultrastructure of interna of Peltogastridae, some crucial aspects of morphology are still unknown.