Florent's Guide To The

Tropical Reefs

Orangutan Crab
Oncinopus sp. 1
Orangutan Crab
Category: Decorator Crabs
Scientific Name: Oncinopus sp. 1
Synonyms: Achaeus japonicus
Size: Up to 1 in. (2.5 cm)  
Depth: 10-75 ft. (3-23 m)
Distribution: West Pacific, Indonesia
Formerly classified as Achaeus japonicus, genus identification tentative
Arthropoda (Phylum) Arthropods
└Crustacea (Subphylum) Crustaceans
 └Multicrustacea (Superclass) Typical Crustaceans
  └Malacostraca (Class) Malacostracans
   └Eumalacostraca (Subclass) Decapods, Isopods, and Allies
    └Eucarida (Superorder)
     └Decapoda (Order) Decapods
      └Pleocyemata (Suborder)
       └Brachyura (Infraorder) True Crabs
        └Majoidea (Superfamily)
         └Inachidae (Family) Decorator Crabs
          └Oncinopus (Genus)
           └O. sp. 1 (Species)

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© 2026 Florent Charpin