PORT PHILLIP BAY


Smooth Seaweed Crab 

Naxia aurita (Latreille, 1825)

View scientific description and taxonomy

Scientific Details

Carapace pear-shaped, strongly narrowing anteriorly, with mesogastric tubercle; surface smooth between groups of strong curled setae. Rostral spines stout, straight, divergent; hepatic spine sharp. Anterolateral angle of basal antennal article with short spine. Preorbital and antorbital spines broad and triangular; intercalated spine well separated from supraorbital eave, directed laterally; postorbital and hepatic spines well separated at base. Walking legs with propodi only slightly expanded.

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:
Majidae
Subfamily:
Majinae
Genus:
Naxia
Species:
aurita

General Description

Rostral spines stout, straight, divergent; hepatic spine sharp. Anterolateral angle of basal antennal article with short spine. Preorbital and antorbital spines broad and triangular; intercalated spine well separated from supraorbital eave, directed laterally; postorbital and hepatic spines well separated at base. Walking legs with propodi only slightly expanded. Yellow-brown. Carapace up to 7 cm long.

Biology

A common seaweed crab among subtidal algal beds of sheltered shores. The crab is yellow-brown and can be twice the size of the ramshorn crab. In both species, males have stronger claws than females. This is the smoothest of the four species and the most common in Victoria and South Australia.

Habitat

Low intertidal, to 108 m depth.

Soft substrates

Reefs

Coastal shores

Distribution guide

Southern temperate oceans, including southern Australia.

Species Group

Crabs and allies Crabs

Depth

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

Water Column

On or near sea floor

Max Size

7 cm

Diet

Organic matter

Harmful

Not harmful but a nip from claws could be painful.

Commercial Species

No

Global Dispersal

Native to Australia

Species Code

MoV 3867

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, Smooth Seaweed Crab, Naxia aurita, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 23 Aug 2017, http://portphillipmarinelife.net.au:8098/species/4194

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