Species Account

Musculus discors (Linnaeus, 1767)

Mytiloidea : Mytilidae

Tebble name: Musculus discors (Linnaeus)
Smith & Heppell name: Musculus discors (L., 1767)

To size: To 12mm. Shell Structure: Thin but not fragile. Equivalve: Equivalve. Equilateral: Strongly inequilateral beaks close to the anterior margin. Tumidity: Not inflated, umbos low. Outline: Modioliform; ligament margin long, not sloping steeply, angled to posterior dorsal margin; posterior rounded; ventral margin long, more or less straight but often depressed adjacent to non ribbed area; anterior narrow, rounded.

Sculpture: Radially ribbed except for smooth median area; 30-40 flat posterior ribs often faint, interspaces narrow; 9-12 prominent anterior ribs; Overall with comarginal lines and growth stops. Margin: Crenulate where radial ribs meet margin. Ligament: Deeply inset extending for most of the posterior dorsal margin. Hinge: Hinge plate narrow, few large dysodont teeth posterior of ligament distinct from marginal crenulations, otherwise smooth. Pallial Musculature: Mostly obscure. Periostracum: Green to greenish brown, thin, persistent. Colour: Grayish white, internally lustrous.

Distribution & Ecology

Lower intertidal and shallow sublittoral attached to rocks and algae, occasionally forming dense rafts on stable gravel bottoms.

Depth Range
Continental Shelf (to 200m)

Additional Information & Related Species


Listed are literature citing Musculus discors (Linnaeus, 1767). Reference containing the species Type Description is highlighted.

Linnaeus C 1767. Systema Naturae. Editio duodecima. 1. Regnum Animale. 1&2 Homliae, Laurentii Salvii. 1-532: 533-1327.


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Record last modified: 22/03/2016