PORT PHILLIP BAY


Mud Ark 

Anadara trapezia (Deshayes, 1840)

View scientific description and taxonomy

Scientific Details

Shells of this family are often quite large, heavy and with strong radial or cancellate sculpture. There is a long, usually straight taxodont hinge with the ligament external, sometimes situated on an expanded area above hinge and between umbones. Most species have a thick fibrous periostracum which maybe hirsute (hair like). Many species are attached to the substrate by a well developed byssus and there may be a ventral byssal gape (Arca), but others are free living as adults and without a byssus.

Taxonomy

Phylum:
Mollusca
Subphylum:
Conchifera
Class:
Bivalvia
Subclass:
Pteriomorphia
Order:
Arcoida
Superfamily:
Arcoidea
Family:
Arcidae
Genus:
Anadara
Subgenus:
Anadara
Species:
trapezia

Other Names

  • Sydney Cockle
  • Trapezoid Mud Ark

General Description

The shells of this species are heavy, obliquely ovate, with a thick external coating (periostracum), particularly at the posterior. Exterior sculpture of broad, strong, radial ribs. The adults are usually without a thread-like byssus. Shell up to 8 cm across.

Biology

This species burrows in the mud. It belongs to a group of bivalves that mainly occur in tropical waters of northern Australia, of which only three species live in Victorian waters.

Habitat

In mud, from low tide to shallow subtidal areas.

Soft substrates

Distribution guide

Southern Australia, excluding Tasmania.

Species Group

Sea snails and shells Bivalves

Depth

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

Water Column

On or near sea floor

Max Size

8 cm

Diet

Plankton or Particles

Commercial Species

Yes

Global Dispersal

Native to Australia

Species Code

MoV 1561

Conservation Status

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

Author

article author Boyd, S.

Sue Boyd is an Honorary Associate in marine invertebrates at Museum Victoria.

citation

Cite this page as:
Boyd, S., 2011, Mud Ark, Anadara trapezia, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 17 Aug 2017, http://portphillipmarinelife.net.au:8098/species/7851

Text: creative commons cc by licence