Species Account

Astarte elliptica (Brown, 1827)

Crassatelloidea : Astartidae

Tebble name: Astarte elliptica (Brown)
Smith & Heppell name: Tridonta elliptica (Brown, 1827)

To size: To 35mm. Shell Structure: Relatively solid. Equivalve: Equivalve. Equilateral: Relatively inequilateral, the beaks lie approximately 35% of dorsal margin length from anterior. Tumidity: Slightly compressed. Outline: Broadly rounded oval, height of shell approximately 70% of the length. Posterior dorsal margin long, gently sloping, very slightly convex to almost straight; anterior dorsal margin more steeply sloping and strongly concave; anterior and posterior ends bluntly rounded; ventral margin gently rounded; lunule very distinct, sunken, elongate heart-shaped with well defined, raised edges; escutcheon distinct, lanceolate, with very well defined raised edges. Beaks prosogyrous.

Sculpture: Prominent raised concentric ridges (up to 30 in adults) with blunt crests and numerous irregular concentric lines which are also present on the raised ridges. The ridges become less prominent towards the shell margins. Margin: Smooth. Ligament: Broad, distinct but not prominently raised, runs for approximately one third the length of the escutcheon. Hinge: Heterodont: Robust hinge plate; right valve with 2 solid, blunt cardinal teeth, the posterior tooth is thin and inconspicuous and the anterior tooth is broad; left valve with 3 blunt cardinal teeth, the 2 anterior teeth are relatively broad and solid whereas the posterior cardinal is very thin and inconspicuous. Pallial Musculature: Entire. Periostracum: Ranges from yellowy brown to dark brown, almost black. Dull surface texture with a mesh of microscopic, elliptical-oval pits. Colour: White.

Distribution & Ecology

Mostly around northern coasts of Britain and Ireland, rare or absent in the Irish Sea, southern North Sea and English Channel.

Lives in a range of clean, silty and muddy sands and gravels from the near sub-littoral towards the mid-shelf, depth range c.5m - >150m, but most frequently in depths <50m.

Depth Range
Continental Shelf (to 200m)

Additional Information & Related Species

Key Features & Similar Species

Many descriptions focus on the nature of the inner margin, smooth in A. elliptica and crenulate in A. sulcata. Tebble (1966) notes that the inner margin is smooth in some individuals of A. sulcata but we have observed that many if not all juvenile shells and many moderately sized shells have smooth margins. The character “smooth inner margin” is therefore not reliable for distinguishing these species. When “elliptica” shaped shells have retained a strong sculpture they do resemble A. sulcata and the periostracum is a better character to confirm identity. In A. elliptica the relatively coarse netted structure is quite distinct from the wavy linear pattern seen in A. sulcata.

Related Species

References

Listed are literature citing Astarte elliptica (Brown, 1827). Reference containing the species Type Description is highlighted.

Brown T 1827. Illustrations of the recent conchology of Great Britain and Ireland WH & D Lizars, Edinburgh. 125pp, 52pls.

Resources

  • Conchological Society of Great Britain & Ireland
    Provides resources for understanding, identifying, recording, and conserving molluscs
  • CLEMAM
    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.

Record last modified: 15/01/2014