On Biology of Two Sympatric Species of Hermit Crab (Crustacea, Decapoda, Paguridae) at St. Chad's, Newfoundland

NAFO Sci. Coun. Studies, 34:7-17

H. J. Squires and G. P. Ennis and G. Dawe

14 Solomons Drung, Portugal Cove-St. Philips
Newfoundland, Canada A1M 2C5

Abstract

Two sympatric species of Hermit Crab, Pagurus acadianus and P. arcuatus, from the sublittoral near St. Chads, Newfoundland, have many similarities in their life history. These are expressed in their feeding, maturities of females (both species hatching eggs in early spring, extruding eggs in late autumn and carrying eggs through the winter), finding shells plentiful at small sizes but scarce at large sizes, and availability at a sublittoral station throughout the year. Differences seen were low rate of parasitization with Peltogaster paguri in P. acadianus: only one in almost five hundred specimens, while there were about 18% in P. arcuatus; and in the former slightly higher fecundity, longer period of male maturity, somewhat larger size, and, as shown earlier, lower frequency in plankton from the area. Percent of ectocommensal protozoans on gills was low in P. acadianus but high in P. arcuatus, while those on setae of maxillule were high in both species.