Diplodonta rotundata (Montagu, 1803)Ungulinoidea : Ungulinidae
To size: To 25mm. Shell Structure: Thin, solid. Equivalve: Equivalve. Equilateral: Inequilateral, beaks to anterior. Tumidity: Moderately tumid. Outline: Subcircular, posterior dorsal margin short, almost straight to a broadly rounded posterior margin. Anterior and posterior dorsal margins roughly equal in length, narrowly rounded anterior margin, broadly rounded posterior margin, medially rounded ventral margin.
Sculpture: Concentric lines. Growth stages clear. Margin: Smooth. Ligament: More than half the length of posterior dorsal margin and yellowy-brown. On a nymphal plate. Hinge: Two cardinals in each valve, LV anterior and RV posterior bifid. No laterals. Pallial Musculature: No pallial sinus. Pallial line continuous. Adductors equal in size. Periostracum: Thin, creamy-yellow. Colour: White.
Distribution & Ecology
A shallow burrower into muddy sand at sublittoral and shallow shelf depths. Recent records are from the south and western sectors with older records from the Irish Sea and southwest of Scotland.
Continental Shelf (to 200m)
Juveniles & Similar Species
Key Features & Similar Species
Listed are literature citing Diplodonta rotundata (Montagu, 1803). Reference containing the species Type Description is highlighted.
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.
Van Aartsen JJ 2000. European marine mollusca: Notes on less well-known species. XVI. Diplodonta eddystonia (Marshall, 1895), with notes on the European Diplodonta species. La Conchiglia. 297: 46-51.
- Conchological Society
of Great Britain & Ireland
Provides resources for understanding, identifying, recording, and conserving molluscs
Check List of European Marine Mollusca
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.
- Malacological Society
- Unitas Malacologica
- Census of Marine Life
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.