original descriptionGofas S. (2007). Rissoidae (Mollusca: Gastropoda) from northeast Atlantic seamounts. <i>Journal of Natural History 41(13–16)</i>: 779–885 page(s): 798-800 [details]
From editor or global species database
Biology Type of larval development: direct (non planktotrophic) denoted by paucispiral protoconch. [details] Diagnosis Shell 2.6- 2.8 mm high, with protoconch of 1.5 whorl and teleoconch of 3.5 whorls; surface of protoconch with 6-7 fine spiral threads; teleoconch with a very strong sculpture of elevated, widely separated axial folds, and spiral cords forming a coarse lattice with projecting knobs at their intersection with the axial sculpture. Two spiral cords on spire whorls, separated between each other and from the sutures by broad interspaces Spiral microsculpture extremely faint and appreciable only under the scanning electron microscope, consisting of granulose threads, and interspaces covered by minute granules. Outer lip bordered with a thick rim overrun by the spiral sculpture; slightly thickened and bearing 5-6 denticles inside. Shell translucent, with one cord (the second one abapically) on spire whorls and two cords (the second and fourth abapically) bearing brownish spots on the nodes intersecting with the ribs.
The few shells from Irving seamount may have a third cord on the spire, and are distinctly smaller and narrower. The shallow subtidal species Alvania sleursi (Amati, 1987) from the Azores is roughly similar but differs in having a strongly keeled protoconch.
The common shelf species Alvania cancellata (Da Costa, 1778) has a similar microsculpture of minute granules aligned spirally on the teleoconch but differs in having a multispiral protoconch. [details] Distribution Meteor seamount, very common in 305-470 m. Hyères seamount, moderately common in 310-480 m; Irving seamount, rare in 270-790 m. Endemic to Meteor group seamounts [details] Type locality Meteor seamount (30º02.0'N, 28º22.1'W, 470 m). [details]