Species Account

Ennucula tenuis (Montagu, 1808)

Nuculoidea : Nuculidae

Tebble name: Nucula tenuis (Montagu)
Smith & Heppell name: Nuculoma tenuis (Montagu, 1803)

To size: To 13mm. Shell Structure: Thin but not fragile. Equivalve: Equivalve. Equilateral: Inequilateral, the beaks lie approximately 20% of dorsal margin length from posterior. Tumidity: (T:L=1:4 [4.5:18.1]) Moderately inflated. Outline: Ovate triangular: height of shell approximately 75% of length; antero-dorsal margin very long, gently curved and sloping; postero-dorsal margin slightly curved, steeply sloping with angled junction at posterior margin; anterior and ventral margins moderately rounded; escutcheon elongate heart-shaped, projecting, generally with poorly defined edges; lunule long, lanceolate with poorly defined edges, noticeably raised. Umbo slightly swollen.

Sculpture: Primary sculpture of numerous very fine, closely-spaced, concentric lines and some growth stops. Margin: Smooth. Ligament: Internal, opisthodetic, elongate triangular ligament seated in a well-developed resilifer. A thin, barely visible, external ligament lies anterior to the beaks. Hinge: Taxodont: Broad and continuous hinge plate with a well-developed resilifer. Teeth long and pointed, usually 8-10 posterior and 16-18 anterior. The teeth extend across the top of the resilifer. Pallial Musculature: Pallial line continuous with no pallial sinus. Adductor muscle scars oval, more or less equal in size and indistinct. Periostracum: Glossy, grey green, green to dark olive, often darker around the outer margin, sometimes iridescent. Colour: White to bluey grey, slightly nacreous. Inside of shell nacreous.

Distribution & Ecology

Occurs all around Britain and Ireland but is absent from the English Channel and southern North Sea. Mud and substrates such as sand and gravel which have a muddy element. Occurs from inshore in c. 10m to the outer continental shelf in depths of up to 200m.

Depth Range
Continental Shelf (to 200m)

Additional Information & Related Species


Listed are literature citing Ennucula tenuis (Montagu, 1808). Reference containing the species Type Description is highlighted.

Allen J A 1954. A comparative study of the British species of Nucula and Nuculana. Journal of the Marine Biological Association of the United Kingdom. 33: 457-472.
Harvey R. & Gage J.D. 1995. Reproduction and recruitment of Nuculoma tenuis (Bivalvia: Nuculoida) from Loch Etive, Scotland. Journal of Molluscan Studies. 61 (4): 409-420.
Montagu G 1808. Testacea Britannica - Supplement Exeter. 183pp + pls 17-30.


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Record last modified: 17/05/2016