Species Account

Bentharca asperula (Dall 1881)

Arcoidea : Arcidae

Tebble name: n/a
Smith & Heppell name: n/a

To size: To 10mm. Shell Structure: Thin, opaque. Equivalve: Equivalve. Equilateral: Inequilateral, beaks at about 1/4 length of dorsal margin from anterior. Tumidity: Not inflated. Outline: Trapezoidal – wedge shaped, posterior greatly expanded, umbos low; dorsal margin long, straight; posterior margin broadly rounded; ventral and anterior margins continuous gently curved with a prominent byssus indentation; anterior roundly pointed. Contour: Posterior angle indistinct; median area with byssal sinus; dorsal area narrow, flat.

Sculpture: Weak, primarily of well spaced, comarginal, low ridges these cut by radial rows of bristle insertion marks. Margin: Inner margin smooth. Ligament: Duplivincular, v-shaped ligament bands arising from posterior of dorsal area at first, then between beaks. Hinge: Taxodont, teeth very small, in two series separated by an edentulous space, set on a narrow straight hinge plate; up to 5 anterior and 6 posterior teeth; anterior set angled obliquely, posterior set subparallel to dorsal margin. Pallial Musculature: Adductor scars unequal, anterior is smaller than posterior. Periostracum: Of brown to dark brown bristles over the posterior area, as frills on median and anterior. Colour: White.

Distribution & Ecology

Attached by a thin byssus to small stones, gravel and often the shells of Limopsis tenella. At the abyssal rise and abyssal depths, generally greater than 2000m. Rare in Rockall Trough, more frequent in Biscay basin.

Depth Range
Bathyal (500 - 2000m)
Abyssal Rise (2000 - 4000m)
Abyssal Plain (4000m +)

Additional Information & Related Species

Key Features & Similar Species

Wedge shape and co-marginal sculpture is unlike all other deep water arcids.

Related Species


Listed are literature citing Bentharca asperula (Dall 1881). Reference containing the species Type Description is highlighted.

Dall W H 1881. Reports on the results of dredging, under the supervision of Alexander Agassiz, in the Gulf of Mexico and in the Caribbean Sea, 1877-79, by the U.S. Coast Survey Steamer “Blake”. XV, Preliminary report on the Mollusca. Bulletin of the Museum of Comparative Zoology, Harvard. 9: 33-144.
Oliver G & Allen J A 1980. The Functional and Adaptive Morphology of the Deep-Sea Species of the Arcacea (Mollusca: Bivalvia) from the Atlantic. Philosophical Transactions of the Royal Society of London Series B. 291: 45-76.


  • Conchological Society of Great Britain & Ireland
    Provides resources for understanding, identifying, recording, and conserving molluscs
    Check List of European Marine Mollusca
  • MarLIN
    The Marine Life Information Network for Britain and Ireland (MarLIN) provides information for marine environmental management, protection and education. It is a centre of excellence in spatially based and time-series marine biological information and supports good stewardship in the marine environment.
  • NBN Gateway
    National Biodiversity Network's Gateway. Use it to explore UK biodiversity data, as contributed by participating data providers.
  • BivAToL
  • MarBEF
  • Malacological Society
  • Unitas Malacologica
  • Census of Marine Life
  • MarBEF
    MarBEF, a network of excellence funded by the European Union and consisting of 94 European marine institutes, is a platform to integrate and disseminate knowledge and expertise on marine biodiversity, with links to researchers, industry, stakeholders and the general public.

Image Gallery

Record last modified: 22/03/2016