Species Account

Myonera demistriata Allen & Morgan, 1981

Verticordioidea : Cuspidariidae

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

Notes on Nomenclature

Not included in CLEMAM – deep-water species.
In WoRMS as
Bathyneara hadalis (Knudsen, 1970), however, Knudsen describes hadalis as compressed and without a sharply demarcated posterior projection and the line drawing shows a short, slightly convex anterior dorsal margin. Our specimen is moderately tumid with an elongate rostrum and a long anterior dorsal margin, matching Allen & Morgan’s image.

To size: To 10mm. Shell Structure: Thin, fragile, hyaline. Equivalve: Equivalve. Equilateral: Equilateral, beaks close to midline. Tumidity: Moderate. Outline: Body of shell narrowly subovate, umbos projecting but not inflated; anterior dorsal slope long, irregularly straight and forming a narrow curve with anterior ventral margin which curves evenly with broadly curving ventral margin. Rostrum a little shorter than body length, dorsal margin straight sloping gently, ventral margin weakly concave, posterior sulcus weak.

Sculpture: Rostrum set off by a prominet radial carinate rib, 6-7 radial ribs decreasing in prominence anteriorly over median area, anterior area with 9-11 concentric ridges. Rostrum with 5-7 radial riblets. Fine concentric striations overall but most prominent on rostrum. Margin: Margin dentate where largest ribs intersect edges. Ligament: Internal, on a small chondrophore lying beneath the beaks. Hinge: Teeth absent. Pallial Musculature: Indistinct. Periostracum: Obscure. Colour: White, semitransparent.

Distribution & Ecology

An abyssal species recorded here from the Rockall Trough but originally described from the Western Atlantic Basin by Allen & Morgan (1981).

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

Additional Information & Related Species


Listed are literature citing Myonera demistriata Allen & Morgan, 1981. Reference containing the species Type Description is highlighted.

Allen J A & Morgan R E 1981. The functional morphology of Atlantic deep water species of the families Cuspidariidae and Poromyidae (Bivalvia): an analysis of the evolution of the septibranch condition. Philosophical Transactions of the Royal Society of London Series B. 294: 413-546.


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Record last modified: 22/03/2016