Alcithoe arabica

Alcithoe arabica, common name Arabic volute, is a species of very large sea snail, a marine gastropod mollusc in the family Volutidae, the volutes.

Distribution
This species is endemic to New Zealand.

Description
Shells of Alcithoe arabica can reach a height of 75 - 225 mm and a width of 88 mm. These shells are usually large, solid, fusiform, with relatively weak tubercles on the shoulder of the body whorl. The shell aperture is high with a thickened, rounded outer lip. The external surface is yellowish-white with chestnut zig-zac markings, forming five bands on the body whorl. These zig-zag markings were thought to resemble Arabic writing, giving rise to the name of the species.

There is no operculum in A. arabica. Individuals have a large grey to brown foot, flecked with purple and orange markings.

Ecology
These sea snails live in subtidal waters on soft sediments. Alcithoe arabica are able to move quite quickly on the soft substrate. They feed on bivalves that they smother using their large foot. The rounded, thin shelled eggs of this species are laid on stones or other shells.

Subspecies

 * Alcithoe arabica motutaraensis Powell, 1928
 * Alcithoe arabica swainsoni Marwick, 1926