Alcithoe arabica

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Alcithoe arabica
Shouldered form of Alcithoe arabica
Shouldered form of Alcithoe arabica
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Order: Sorbeoconcha
Family: Volutidae
Genus: Alcithoe
Species: A. arabica
Binomial name
Alcithoe arabica
(Gmelin, 1791)
Synonyms

Alcithoe swainsoni Marwick, 1926

Alcithoe arabica is a very large sea snail, a marine gastropod mollusc in the family Volutidae, the volutes.

Contents

[edit] Distribution

This species is endemic to New Zealand, found all around New Zealand's coast.

[edit] Habitat

This volute is found intertidally, and to about 70 m, common on mud flats and fine sandy bottoms.

[edit] Description

The shell is large and solid, variable in size, shape, sculpture and coloration, but always with a free-edged columellar parietal callus plate. There are four to six strong, oblique pillar plaits.

The external shell colour is usually pale pinkish-buff, with a bold pattern of dark reddish-brown maculations, which resolve into four zones of zigzag markings on the body whorl.

Alcithoe arabica (smooth form)
Alcithoe arabica (smooth form)

There are two distinct forms, a smooth form without nodules on the body whorl, and a shouldered form. The shouldered form has a single peripheral row of sharply pointed tubercles that tend to be vertically compressed. The smooth form was previously known as Alcithoe swainsoni, and that is now a synonym.

Alcithoe arabica (smooth form, underside view)
Alcithoe arabica (smooth form, underside view)

The radula consists of a single row of tricuspid central teeth, the cusps long slender and erect.

The maximum shell height is 200 mm, and width 88 mm.

[edit] References