Species Account

Kurtiella bidentata (Montagu, 1803)

Galeommatoidea : Montacutidae

Tebble name: Mysella bidentata (Montagu)
Smith & Heppell name: Mysella bidentata (Montagu, 1803)

To size: To 6mm. Shell Structure: Thin, rather fragile. Equivalve: Equivalve. Equilateral: Inequilateral, beaks distinctly behind midline. Tumidity: Variable, some distinctly tumid. Outline: Subovate, anterior dorsal margin almost straight and sloping gently; anterior margin broadly rounded, ventral gently curved; posterior dorsal margin short slightly sunken; posterior margin subtruncate and distinctly narrower than anterior. Contour: Posterior area set off by a weak ridge; lunule shallow, narrow, long.

Sculpture: Of fine concentric lines and growth stops;. Margin: Inner margin smooth. Ligament: Internal, set beneath the beaks. Hinge: RV with single strong cardinal flanges either side of ligament; LV with single marginal flanges either side of ligament. Pallial Musculature: Pallial line wide, entire. Periostracum: Thin, pale, often with ferruginous or manganese coating. Colour: Dirty white. Additional Characters: Prodissoconch 400-580 µm, P1 smooth, P2 with faint co-marginal growth lines.

Distribution & Ecology

Intertidal in mud-filled crevices and in sublittoral and shelf mud and muddy sand. Associated with ophiuroid dominated communities but intertidally can be found with Epilepton along with sipunculans and polychaetes.

Depth Range
Continental Shelf (to 200m)

Additional Information & Related Species

Key Features & Similar Species

Species of the genus Kurtiella are characterised by the divergent single lateral hinge teeth and deep inset internal ligament. Kurtiella bidentata can be abundant in near shore Abra/Amphiura communities and is noticable from its dark encrusted appearance. Other species of Kurtiella described here are deep water and only K. tumidula is likely to be encountered, but that species has a narrow pointed posterior and broadly rounded anterior.

Additional Comments

Some populations have shells that are distinctly heavier, with stronger teeth and a more triangular outline. These are the S-form of Ockelmann & Muus (1978) as opposed to the more typical shells that they called the M-form.

Related Species


Listed are literature citing Kurtiella bidentata (Montagu, 1803). Reference containing the species Type Description is highlighted.

Gofas, S. & Salas, C. 2008. A review of European ‘Mysella’ species (Bivalvia: Montacutidae), with description of Kurtiella new genus. Journal of Molluscan Studies. 74: 119-135.
Kallonas M, Zenetos A & Gofas S 1999. Notes on the Ecology and Distribution of Microbivalvia in Greek Waters. La Conchiglia. 291: 11-20.
Montagu G 1803. Testacea Britannica, or natural history of British shells, marine, land and the fresh-water, including the most minute: systematically arranged and embellished with figures Romsey, London. 606pp, 16pls.
Ockelmann KW & Muus K 1978. The biology, ecology and behaviour of the bivalve Mysella bidentata (Montagu). Ophelia. 17 (1): 1-93.
Van Aartsen JJ 1996. Galeommatacea and Cyamiacea Part II. La Conchiglia. 281: 27-53, + 61.


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Record last modified: 17/05/2016