PORT PHILLIP BAY


Purple-mottled Shore Crab 

Cyclograpsus granulosus Milne Edwards, 1853

View scientific description and taxonomy

Scientific Details

Frontal region of carapace distinctly granulate, with at most 2-3 faint ridges obliquely connecting to posterolateral margin; infraorbital margin open, antenna 2 free to enter orbit; anterolateral corners rounded; lateral margin behind orbital angle without teeth. Pterygostomial region with granules but lacking distinct reticulate pattern. Sternum, maxilliped 3 and bases of walking legs with short sparse hairs. Carapace mottled variably with red-brown or purple on yellow.

Source: Poore, G.C.B. (2004) Marine decapod Crustacea of southern Australia. A guide to identification (with chapter on Stomatopoda by Shane Ahyong). CSIRO Publishing, Melbourne, 574 pp.

Taxonomy

Phylum:
Arthropoda
Subphylum:
Crustacea
Class:
Malacostraca
Subclass:
Eumalacostraca
Superorder:
Eucarida
Order:
Decapoda
Suborder:
Pleocyemata
Infraorder:
Brachyura
Family:
Grapsidae
Subfamily:
Cyclograpsinae
Genus:
Cyclograpsus
Species:
granulosus

General Description

Body granulate, mottled with variable patterns of red, brown, purple and yellow. The sides of the carapace are curved and without teeth. Up to 4 cm wide (carapace).

Biology

Purple-mottled Shore Crabs are very active and race for shelter when disturbed. Because they can survive for several hours out of water they are able to live above the low-tide level on rocky shores. Shore crabs are scavengers, using their claws to tear apart dead fishes and rotting seaweed. Purple-mottled Shore Crabs can breed (hybridise) with a closely related shore crab species.

Habitat

Under rocks at mid to high intertidal levels.

Reefs

Coastal shores

Distribution guide

South-eastern Australia.

Species Group

Crabs and allies › Crabs

Depth

Shore (0-1 m)
Shallow (1-30 m)

Water Column

On or near sea floor

Max Size

4 cm

Diet

Carnivore

Harmful

Not harmful but a nip from claws could be painful.

Commercial Species

No

Global Dispersal

Native to Australia

Species Code

MoV 1590

Conservation Status

  • DSE Advisory List : Not listed
  • EPBC Act 1999 : Not listed
  • IUCN Red List : Not listed

Author

article author Taylor, J.

Dr. Jo Taylor is the Sciences Collections Online Coordinator at Museum Victoria.

Author

article author Poore, G.C.B.

Dr. Gary Poore is Principal Curator Emeritus at Museum Victoria.

citation

Cite this page as:
Taylor, J. & Poore, G.C.B., 2011, Purple-mottled Shore Crab, Cyclograpsus granulosus, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 25 Feb 2025, http://136.154.202.208:8098/species/3905

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