Thoristella oppressa

Taxobox
name = "Thoristella oppressa"
status =
regnum = Animalia
phylum = Mollusca
classis = Gastropoda
subclassis = Prosobranchia
ordo = Archaeogastropoda
superfamilia = Trochacea
familia = Trochidae
genus = "Thoristella"
species = "T. oppressa"
binomial = "Thoristella oppressa"
binomial_authority = (Hutton, 1878)

"Thoristella oppressa" is a species of very small sea snail, marine gastropod molluscs in the family Trochidae, the top snails or top shells.

Distribution

This top shell is endemic to the east coast of the North Island of New Zealand, north of East Cape.

Habitat

This small species is quite commonly found on the fronds of the flapjack seaweed "Carpophyllum maschalocarpum" and the kelp "Ecklonia radiata", and also under stones, at low tide.

Description

The shell is small, solid and conical, prominently bi-angled by a bluntly rounded subsutural fold, and a similar peripheral fold. The sculpture is of fine closely spaced spiral lirae.

Shell coloration is greenish-grey, darker spirally lined, either continuously or intermittently, in the form of dots and dashes, occasionally with larger maculations on both angulations. The umbilical area is white, and the interior of the aperture is pale iridescent.

The body of the animal is black.

The shell height is up to 6 mm, and width up to 6 mm.

References

* Powell A. W. B., "New Zealand Mollusca", William Collins Publishers Ltd, Auckland, New Zealand 1979 ISBN 0-00-216906-1
* Miller M & Batt G, "Reef and Beach Life of New Zealand", William Collins (New Zealand) Ltd, Auckland, New Zealand 1973