Yoldiella intermedia Sars, 1865

Phylum:Mollusca Linnaeus, 1758
Class:Bivalvia Linnaeus, 1758
Order:Nuculanida Carter, J. G., Campbell, D. C. & M. R. Campbell, 2000
Family:Yoldiidae Dall, 1908
Genus:Yoldiella A. E. Verrill & Bush, 1897
Synonyms:Yoldia intermedia M. Sars, 1865; Yoldia oleacina Dall, 1916; Portlandia intermedia (M.Sars, 1865)

To size: To 13mm.

Shell Structure: Solid, but not robust. Equivalve: Equivalve. Equilateral: Moderately inequilateral, the beaks lie at least 40% of dorsal margin length from anterior. Becomes more inequilateral with growth. Tumidity: Moderately inflated. Outline: Elongate-oval: antero-dorsal margin short, slightly curved; postero-dorsal margin long, almost horizontal with a dorsal margin – posterior margin junction; lower posterior margin obliquely truncated; to a lesser extent the upper posterior margin may also be obliquely truncated, creating a pointed or weakly rostrate posterior margin; anterior margin rounded; ventral margin shallowly curved. Dorsal margin crimped either side of the umbo. Elongate lunule and escutcheon. Umbo broad, swollen and prominent above the dorsal margin, well to the anterior of midline.

Sculpture: Virtually lacking sculpture, with only faint concentric lines and growth stops. Margin: Smooth. Ligament: Amphidetic, with the ligament seated in a well developed, projecting chondrophore. Hinge: Taxodont: Hinge plate continuous, relatively narrow with 5-6 blunt, chevron-shaped teeth on either side of the ligament. Colour: Glossy, dark straw-coloured with darker bands at growth stops.

Additional Characters: The hind-gut forms a simple, rounded loop on the right side of the body.

Depth: 5 - 500 m.

Author: Manushin Igor E. / 30.09.2015
Last edit: Manushin Igor E. / 30.09.2015

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