''Alaba polyaulax'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

, a marine

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Litiopidae Litiopidae, common name litiopids, is a family of small sea snails, marine gastropod molluscs in the clade Sorbeoconcha. According to the taxonomy of the Gastropoda by Bouchet & Rocroi (2005) the family Litiopidae has no subfamilies. Genera ...

Description

The length of the shell attains 7 mm, its diameter 2 mm. (Original description) Shell acutely conical, elongate, of a greenish horn-colour, irregularly marked with reddish, interrupted longitudinal streaks; whorls 10, protoconch eroded in all available specimens, the other whorls very regularly spirally grooved, the body whorl having 17 grooves and the penultimate one 8 in the type specimen; the whorls are slightly convex with shallow suture; they are also closely longitudinally ribbed, but this axial sculpture is almost microscopic and visible on the spiral ribs only under a high power; it is more obvious where it crosses the grooves ; peristome simple; aperture rather elongate The shell is sharply conical and elongated, with a greenish horn coloration marked irregularly by reddish, interrupted longitudinal streaks. It consists of 10

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). In nature File:Photograph and axial plane floral diagra ...

s. 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 " ...

is eroded in all available specimens. The subsequent whorls are very consistently spirally grooved, with 17 grooves on the

body whorl The body whorl is part of the morphology (biology), morphology of the gastropod shell, 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 ...

and 8 on the penultimate whorl in the type specimen. The whorls are slightly convex, with a shallow suture, and are closely longitudinally ribbed. However, this axial sculpture is almost microscopic and visible on the spiral ribs only under high magnification. It becomes more evident where it intersects the grooves. The peristome is simple, and the

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

is rather elongated.

Distribution

This species occurs in the Indian Ocean off

Isipingo Isipingo is a town situated south of Durban in KwaZulu-Natal, South Africa and currently forms part of eThekwini Metropolitan Municipality. The town is named after the Siphingo River, which in turn is thought to be named (in the Zulu language) ...

, South Africa

References

External links

* {{Taxonbar, from=Q106076617 polyaulax Gastropods described in 1923 Marine molluscs of Africa Molluscs of the Indian Ocean