Thais orbita

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Thais orbita
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Orthogastropoda
Superorder: Caenogastropoda
Order: Sorbeoconcha
Suborder: Hypsogastropoda
Infraorder: Neogastropoda
Superfamily: Muricoidea
Family: Muricidae
Genus: Thais
Species: T. orbita
Binomial name
Thais orbita
(Martyn, 1784)

Thais orbita, or the white rock shell, is a large species of predatory sea snail, a marine gastropod mollusc in the family Muricidae, the rock snails.

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[edit] Distribution

This species is endemic to southern Australia and the North Island of New Zealand.

[edit] Habitat

This snail is found in the intertidal zone and is quite common on rocky shores, both in sheltered waters and on the open coast.

[edit] Shell description

The shell is large and strong to massive, ovate in shape. The sculpture is very variable, usually with a few broad low spiral ridges, separated by wider interspaces, bearing several spiral threads. In some shells the spiral ridges and grooves are massive with deep interspaces. The thick operculum is ovate-lunate.

The shell coloration is a dull creamy-white, sometimes obscurely spirally lined in light reddish-brown. The interior of the aperture and the parietal callus is also creamy-white. The lower part of the body and the siphon are reddish-brown, and the rest is white.

The shell height is up to 118 mm, and the width is up to 73 mm

[edit] Life habits

The favourite food of this species is mussels, and it is capable of wedging the shells of these bivalves open by using the lip of its own shell.

The egg cases of this species are straight sided and flat topped, fitting together like honeycomb, and are often seen attached to rocks. They are cream-coloured, often tinged with lilac.

[edit] References