Species Account

Malletia johnsoni Clark, 1961

Nuculanoidea : Malletiidae

Tebble name: n/a
Smith & Heppell name: Malletia johnsoni Clark, 1961

Notes on Nomenclature

Not included in CLEMAM – deep-water species

To size: To 17mm. Shell Structure: Thin, fragile. Equivalve: Equivalve. Equilateral: Inequilateral, beaks situated to the anterior of midline, approximately 35% of total length from anterior end. Tumidity: Moderately inflated but rather compressed posteriorly. Outline: Rounded rectangular: antero-dorsal margin short, gently sloping; anterior end rounded; postero-dorsal margin long, straight and slightly raised, with a slight dorsal margin - posterior margin junction; posterior end broad, slightly rounded to almost truncated. Ventral margin long, very shallowly rounded to almost straight. Umbo narrow, slightly pointed and raised above the dorsal margin.

Sculpture: Virtually smooth, with only very faint, closely spaced concentric lines. Margin: Smooth. Ligament: External, exterior part long, at least half the length of the postero-dorsal margin, prominent, raised, straw-coloured; anterior part narrow and not raised. Hinge: Taxodont: Hinge plate rather narrow but broadening away from the umbos; straight in the posterior part and sloping in the anterior part; moderately pointed chevron-shaped teeth, up to 36 posterior and 16-20 anterior. Resilium. Pallial Musculature: Pallial sinus broad and deep, extending approximately half way across the shell. Periostracum: Glossy, slightly iridescent, greyish to slightly greenish, sometimes browner around the outer margins (especially the anterior end). Colour: Translucent white. Additional Characters: The hind-gut forms a simple, rounded loop on the right side of the body.

Distribution & Ecology

Rockall Trough in depths >1500m. Widespread in the North and South Atlantic deep-sea basins. Mostly in depths ranging from 1000 to >3000m

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

Additional Information & Related Species

Related Species

Nuculanoidea : Malletiidae


Listed are literature citing Malletia johnsoni Clark, 1961. Reference containing the species Type Description is highlighted.

Clark A H Jr 1961. Abyssal mollusks from the South Atlantic Ocean. Bulletin of the Museum of Comparative Zoology, Harvard. 125: 345-387.
Sanders H.L. & Allen J.A. 1985. Studies on deep sea Protobranchia (Bivalvia): the family Malletiidae. Bulletin of the Natural History Museum, London (Zoology). 49: 195-238.


  • 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.

Record last modified: 22/03/2016