Species Account

Thyasira biplicata (Philippi, 1836)

Thyasiroidea : Thyasiridae

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

Notes on Nomenclature

Previously here as Thyasira polygona, but since synonymised with T. biplicata

To size: To 8mm. Shell Structure: Thin. Equivalve: Equivalve. Equilateral: Equilateral. Tumidity: Tumid. Outline: Ovate-polygonal; anterior dorsal margin long, steeply sloping to narrowly rounded anterior margin; ventral margin a broad curve; posterior deeply sinuose with prominent posterior and marginal sinuses. Contour: Posterior sinus and sub-marginal sinus very pronounced, auricle very high and distinctly projecting above the dorsal margin. Lunule distinct.

Sculpture: Smooth except for incremental lines and growth stops. Margin: Inner margin smooth. Ligament: External but deeply sunken within auricle. Hinge: Hinge plate narrow, a weak flange like protuberance in RV. Pallial Musculature: Muscle scars obscure. Periostracum: Thin not persisting. Colour: Shell white. Additional Characters: 2 demibranchs.

Distribution & Ecology

Known from few records at shelf depths in the central North Sea and from deeper sea lochs on the west coast of Scotland. Chemosymbiotic, sporadic occurrence but mostly in deeper shelf situations. The gills have 2 demibranchs is and similar to T. flexuosa. Ecological separation from T. flexuosa not understood.

Depth Range
Continental Shelf (to 200m)

Additional Information & Related Species

References

Listed are literature citing Thyasira biplicata (Philippi, 1836). Reference containing the species Type Description is highlighted.

Killeen I J & Oliver P G 2002. Thyasira polygona (Jeffreys) (Bivalvia: Lucinoidea), an abandoned taxon with a possible amphi Atlantic distribution. Journal of Conchology. 37: 383-390.
Oliver P G & Killeen I J 2002. The Thyasiridae (Mollusca: bivalvia) of the British continental shelf and North Sea Oilfields. Studies in Marine Biodiversity and Systematics from the National Museum of Wales. BIOMOR Reports. 3: 1-73.
Payne C.M. & Allen J.A. 1991. The morphology of deep-sea Thyasiridae (Mollusca: Bivalvia) from the Atlantic Ocean. Philosophical Transactions of the Royal Society of London Series B. 334: 481-566.
Philippi R A 1836. Enumeratio molluscorum Siciliae cum viventium tum in tellure tertiaria fossilium, quae in itinere suo observavit. Vol. 1 Schropp, Berlin. 267pp, 12pls.
Taylor J D, Williams S T & Glover E A 2007. Evolutionary relationships of the bivalve family Thyasiridae (Mollusca: Bivalvia), monophyly and superfamily status. Journal of the Marine Biological Association of the United Kingdom. 87: 565-574.

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.

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Record last modified: 17/05/2016