PORT PHILLIP BAY


Boring Venus Shell 

Irus crenatus (Lamarck, 1818)

View scientific description and taxonomy

Scientific Details

This very large family includes over 500 species worldwide and are found in almost all seas. The family is characterised by a strong hinge with three cardinal teeth in each valve, anterior laterals may be present, but are weak. Shells of this family are moderate to large, often thick and solid, vary greatly in shape from elongate, ovate and quite flattened, to orbicular and inflated. Umbones are approximately median, ligament elongate, external. Shell exterior usually smooth or with concentric sculpture, a few with radial ribs. Periostracum is variable, maybe absent. Adductor muscle scars usually more or less equal, pallial sinus present in most venerids, often shallow. Byssus is usually absent in adults.

Taxonomy

Phylum:
Mollusca
Subphylum:
Conchifera
Class:
Bivalvia
Subclass:
Heterodonta
Order:
Veneroida
Superfamily:
Veneroidea
Family:
Veneridae
Subfamily:
Tapetinae
Genus:
Irus
Subgenus:
Irus
Species:
crenatus

Other Names

  • Crenated Boring Venerid

General Description

Shell shape and sculpture varies: solid, elongate, approximately rectangular in outline. Sculpture well-defined, comprising numerous fine radial lines (striae) intersecting with numerous concentric lines (striae), giving a cancellate appearance. Concentric striae may be finely scaled (lamellate) posteriorly and/or along ventral margin. Exterior shell colour variable, often with blotches of purple, interior white with a brown or purple area in the posterior. Shell up to 4 cm across.

Biology

These bivalves are "rock nestlers", securing themselves to rocks by their byssal threads.

Habitat

Nestled between rocks.

Reefs

Distribution guide

Most states of Australia.

Species Group

Sea snails and shells Bivalves

Depth

Shallow (1-30 m)

Water Column

On or near sea floor

Max Size

4 cm

Diet

Organic matter

Commercial Species

No

Global Dispersal

Recorded in Australia

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, Boring Venus Shell, Irus crenatus, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 30 May 2017, http://portphillipmarinelife.net.au:8098/species/5614

Text: creative commons cc by licence