''Rissoina meteoris'' is a species of minute

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

, a

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk or

micromollusk A micromollusk is a shelled mollusk which is extremely small, even at full adult size. The word is usually, but not exclusively, applied to marine mollusks, although in addition, numerous species of land snails and freshwater mollusks also ...

in the family

Rissoinidae Rissoinidae is a large family of very small and minute sea snails with an operculum, marine gastropod mollusks, in the clade Littorinimorpha. Several genera that were previously part of Rissoinidae have been assigned to the Zebinidae Zebin ...

Description

The height of the very slender shell varies between 5.5 mm to 9.0 mm The

protoconch A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also called ...

consists of 1.25

whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral ...

, and the teleoconch of ca. 10 very flat whorls. The protoconchis smooth, the teleoconch apparently smooth and glossy but with tiny punctures visible only under very high magnification, densely set in spiral bands. The aperture is piriform, channelled at the insertion of outer lip on the previous whorl. The outer lip is definitely opisthocline, thickened but not demarcated from the

body whorl The body whorl is part of the morphology of the shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk. In gastropods In gastropods, the b ...

, with rounded edge, inside slightly swollen near parietal insertion

Distribution

This species is found on the Great Meteor seamount in the northeast Atlantic at a depth of 470 m.

References

* Gofas S. (2007). ''Rissoidae (Mollusca: Gastropoda) from northeast Atlantic seamounts.'' Journal of Natural History 41(13–16): 779–885 page(s): 868-871 Rissoinidae Gastropods described in 2007 {{Rissoinidae-stub