Hyas lyratus Dana, 1851

Common name(s): Lyre crab, Pacific lyre crab
Synonyms:  Sayas lyratus
Phylum Arthropoda
 Subphylum Crustacea
 Class Malacostraca
   Subclass Eumalacostraca
    Superorder Eucarida
     Order Decapoda
      Suborder Pleocyemata
       Infraorder Brachyura
        Family Majidae
Hyas lyratus from 90 m depth, San Juan Channel
(Photo by: Dave Cowles July 1999)
Description:  This Majid crab has a broad, toothed extension on the anterolateral margins of the carapace that make the carapace lyre-shaped.  The carapace is slightly longer than wide, and has no sharp lateral tooth or projection on its posterior half.  Its rostrum is bifid and very broad and flat at the base (picture).

How to Distinguish from Similar Species: The only other local majid crab with a lyre-shaped carapace is Oregonia bifurca, which has a longer rostrum and lives belor 500 m depth.

Geographical Range: Chukchi and Bering Seas south to Puget Sound.

Depth Range: 9 to 640 meters

Habitat: Mixed bottom, especially shelly hash

Biology/Natural History: Carapace is often overgrown with barnacles and other attached species, such as the small tunicate on the base of the rostrum of the species above.


 
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References:

Dichotomous Keys:
  Coffin, 1952
  Flora and Fairbanks, 1966
  Hart, 1982
  Kozloff 1987, 1996
 

General References:
Jensen, 1995

Scientific Articles:
 Wicksten, Mary K., 1976.  Studies on the hooked setae of Hyas lyratus (Brachyura: Majidae).  Syesis 9: pp 367-368


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


A close-up of the rostrum, enlarged from above.  A small tunicate is growing on the base.
Photo by Dave Cowles, July 1999

We capture this crab mainly during deep benthic trawls in the San Juan channel

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This individual, carapace length 4.8 cm, was captured in the San Juan Channel July 2005 at 100-150 m depth.  Photo by Dave Cowles, July 2005


The undersde of a female.  Photo by Dave Cowles, July 2008
 

Hyas_lyratus_Dorsal
A dorsal view of an individual captured between 100-120 m depth in the San Juan Channel. Photo by Dave Cowles, August 2015.

Ventral view
Ventral view of the same individual. Note that the two prongs of the rostrum are wide in the middle, as in Scyra acutifrons, but unlike S. acutifrons they remain wide to the base. Photo by Dave Cowles, August 2015


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