PORT PHILLIP BAY


Deep Water Two-spined Crab 

Pycnoplax meridionalis (Rathbun, 1923)

View scientific description and taxonomy

Scientific Details

Carapace hexagonal (posterolateral margin tapering), widest at junction of anterolateral and posterolateral borders; dorsal surface convex, smooth, regions poorly defined; frontal margin usually entire; anterolateral margins usually armed with 2 teeth. Orbits complete, eyestalk occupying about one-quarter of frontal border. Interantennular septum typically narrow. Maxillipeds 3 with carpus articulating at or near disto internal angle of merus. Walking legs ambulatory, never flattened. Male abdomen with 7 free somites or with somites 3-5 immoveable. Male gonopod 1 moderately stout, weakly curved or sinuous; gonopod 2 usually shorter than first. Male genital openings sternal or sternocoxal, with vas deferens passing along open or closed groove in sternum.

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:
Goneplacidae
Subfamily:
Carcinoplacinae
Genus:
Pycnoplax
Species:
meridionalis

General Description

Carapace hexagonal (posterolateral margin tapering), widest at junction of anterolateral and posterolateral borders; anterolateral border with 2 spines; eyestalk occupying about one-quarter of frontal border; front deflexed, straight, without median notch. First anterolateral spine after orbital tooth, acute and set back about one third way to second anterolateral spine; usually with brown fingers. Up to 3 cm wide.

Biology

This species is more common in deeper waters of Bass Strait and rarely reported from Port Phillip Bay. The abdomen in all crabs is small and tightly held against the underside of the body. Like all crustaceans the sexes are separate and the size of the abdomen distinguishes them: in males it is triangular and inset into the underside. In females it is broad and round and most obvious when the eggs are being carried.

Habitat

Shelf and slope between 126-540 m depth.

Soft substrates

Distribution guide

Southern temperate oceans, including southern Australia.

Species Group

Crabs and allies Crabs

Depth

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

Water Column

On or near sea floor

Max Size

3 cm

Diet

Organic matter

Harmful

Not harmful but a nip from large claws could be painful

Commercial Species

No

Global Dispersal

Native to Australia

Species Code

MoV 3862

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, Deep Water Two-spined Crab, Pycnoplax meridionalis, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 18 Oct 2017, http://portphillipmarinelife.net.au:8098/species/5474

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