Species Account

Ledella ultima (E A Smith, 1885)

Nuculanoidea : Nuculanidae

Tebble name: n/a
Smith & Heppell name: Ledella ultima (E A Smith, 1885)

Notes on Nomenclature

Not included in CLEMAM – deep-water speciesNuculanidae in place of Yoldiidae
Killeen & Turner (2009) use Nuculanidae instead of Yoldiidae in agreement with Ockelmann & Warén (1998) who explan that the distinguishing characters between these two families has never been well documented. Until the Yoldiidae can be clearly distinguished from the Nuculanidae we shall treat them under the single family Nuculanidae.

To size: To 4mm. Shell Structure: Moderately solid becoming massive. Equivalve: Equivalve. Equilateral: Slightly inequilateral, beaks just behind midline. Tumidity: Moderately tumid, becoming obese. Outline: Oval with a short rostrum: antero-dorsal margin sloping; postero-dorsal margin almost straight and sloping; rostrum subtruncate; postero-ventral margin flexuous; ventral margin deeply rounded. Umbo relatively broad and prominent, projecting above the dorsal margin. Contour: Rostrum with a distinct keel.

Sculpture: Of evenly spaced fine, co-marginal ridges. Smoother over the umbo. Margin: Smooth. Ligament: Internal, amphidetic, oval, seated in a relatively broad resilium beneath the beaks. Hinge: Taxodont: Hinge plate relatively solid, becoming massive in obese shells. Robust, blunt, short chevron-shaped teeth, approximately 6-8 either side of the ligament. Pallial Musculature: In obese shells adductor muscle scars deeply impressed. Periostracum: Thin, smooth, greyish green, becoming yellowish with age. Colour: White. Additional Characters: Gut loop with multiple tight coils on the right side.

Distribution & Ecology

Abyssal and bathyal depths in Atlantic south of Rockall.

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

Additional Information & Related Species


Listed are literature citing Ledella ultima (E A Smith, 1885). Reference containing the species Type Description is highlighted.

Olabarria C. 2005. Patterns of bathymetric zonation of bivalves in the Porcupine Sea Bight and adjacent abyssal plain, NE Atlantic. Deep-Sea Research I. 52: 15-31.
Smith E A 1885. Report on the Lamellibranchiata collected by HMS Challenger during the years 1873-1876. Reports of the scientific results of the voyage of HMS “Challenger”, Zoology. 13 (35): 1-341, 25pls.


  • 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