Alcithoe arabica

Taxobox
name = "Alcithoe arabica"


image_caption = Shouldered form of "Alcithoe arabica"
regnum = Animalia
phylum = Mollusca
classis = Gastropoda
ordo = Sorbeoconcha
familia = Volutidae
genus = "Alcithoe"
species = "A. arabica"
binomial = "Alcithoe arabica"
binomial_authority = (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.

Distribution

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

Habitat

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

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.

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.

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.clear

References

* Powell A W B, "New Zealand Mollusca", William Collins Publishers Ltd, Auckland, New Zealand 1979 ISBN 0-00-216906-1
* [http://www.mollusca.co.nz/speciesdetail.php?speciesid=1192&species=Alcithoe%20arabica Photo]