Pagurus stevensae Hart, 1971

Common name(s): Steven's hermit crab

Synonyms:  Pagurus brandtii
Phylum Arthropoda
 Subphylum Crustacea
  Class Malacostraca
   Subclass Eumalacostraca
    Superorder Eucarida
     Order Decapoda
      Suborder Pleocyemata
       Infraorder Anomura
        Family Paguridae
Pagurus stevensae captured at 80 m depth in the San Juan Channel
(Photo by: Dave Cowles July 2001)
Description:  This subtidal hermit crab has a smooth carapace, only part of which (the shield) is calcified.  The rostrum is not pronounced, with a blunt tip.  The carpus of the left cheliped is about 3x as long as wide; while the carpus of the right cheliped is about 2x as long as wide and is not flattened.  The dorsal surface of the left chela does not have a prominent ridge or crest near the midline and the ventral surface of the merus of the right cheliped has no prominent tubercles.  The propodus and dactyl of the left chela meet without a promenent gap in the middle, and the propodus has a double row of divergent spines on the eminence near the midline of its dorsal surface.  The right chela is long and slender, with a granular surface.  There is no white band on the distal part of the merus of the chelipeds.  Color mostly reddish-brown.  No bands on the antennae.

How to Distinguish from Similar Species: P. dalli has only one row of spines on the dorsal surface of its left chela and the carpus of the right cheliped is only about 1.5x as long as wide, plus it has a distinct white band on the distal part of the merus of the chelipeds.

Geographical Range: Akun Island(Bering Sea) to Puget Sound

Depth Range: Subtidal, 5-198 m

Habitat:_On shell/gravel bottoms.

Biology/Natural History: This individual is living in the sponge Suberites suberea forma latus.  It may actually be inside the fragments of a badly eroded shell which the sponge covered.  This species usually lives in sponges, though it may live in a shell as well.



 
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References:

Dichotomous Keys:
  Hart, 1982
  Kozloff 1987, 1996
 

General References:
  Harbo, 1999
  Jensen, 1995

Scientific Articles:
Hart 1971, J. Fish. Res. Board Can. 28(10):1537. (original description)



General Notes and Observations:  Locations, abundances, unusual behaviors:


Another photo of the same individual as above.


The same individual trying to right the sponge.


An underwater photo of Pagurus stevensae by Aaron Baldwin



Authors and Editors of Page:
Dave Cowles (2005):  Created original page