Rahul Sharma (Editor)

Oregonia (genus)

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Kingdom
  
Animalia

Class
  
Malacostraca

Family
  
Oregoniidae

Phylum
  
Arthropoda

Order
  
Decapoda

Subphylum
  
Crustacea

Infraorder
  
Brachyura

Scientific name
  
Oregonia

Rank
  
Genus

Oregonia (genus) httpsuploadwikimediaorgwikipediacommonsthu

Similar
  
Oregonia gracilis, Decapoda, Oregonia bifurca, Pugettia, Hyas

Oregonia is a genus of crabs, comprising two extant species and one fossil species: It is classified under the family Oregoniidae under the spider crab superfamily Majoidea.

Contents

Description

The members of the genus are characterized by subtriangular or suboblong carapaces moderately covered with small protrusions (tubercles). They have large spines on the rear margins of the eye orbits (the postorbital spine) that are situated quite far from the eyestalks. The male chelipeds are elongated. The palms (manus) of the claws are long, compressed, and widen on the outer ends. The walking legs (pereiopods) are slender and decrease in length regularly towards the back. The abdomen (pleon) has seven segments.

Species

Three species are currently recognized under the genus:

  • Oregonia bifurca Rathbun, 1902 – the split-nose crab, found in deep waters of the northern Pacific Ocean, from the Bering Sea to the waters off British Columbia
  • Oregonia gracilis Dana, 1851 – the graceful decorator crab, found in shallow waters of the northern Pacific Ocean, from off Japan to the waters off California
  • †Oregonia spinifera Schweitzer, Feldmann, González-Barba & Vega, 2002 – a fossil species from the Oligocene El Cien Formation of Baja California, Mexico

    • The previously described species O. longimana, O. mutsuensis and O. hirta have all been subsumed into O. gracilis. O. hirta in particular was misidentified as a separate species due to the sexual dimorphism exhibited by majoid crabs. They were actually the females of O. gracilis.

    References

    Oregonia (genus) Wikipedia
    (Text) CC BY-SA