''Sigapatella novaezelandiae'', common name the circular slipper limpet, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of medium-sized

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

, a marine

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

s in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Calyptraeidae The Calyptraeidae are a family of small to medium-sized marine prosobranch gastropods.MolluscaBase. Calyptraeidae Lamarck, 1809. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=141 on ...

.Bouchet, P. (2012). Sigapatella novaezelandiae. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=597421 on 2012-05-14

Description

The size of an adult shell varies between 15 mm and 33 mm. The white or yellowish-white shell is marked by growth lines. The

spire A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spire ...

is often light violaceous. The shell is covered by a thin, fibrous, yellowish

periostracum The periostracum ( ) is a thin, organic coating (or "skin") that is the outermost layer of the shell of many shelled animals, including molluscs and brachiopods. Among molluscs, it is primarily seen in snails and clams, i.e. in gastropods an ...

. The interior of the shell is white, more or less stained or blotched with violet. G.W. Tryon, Manual of Conchology vol. VIII, p. 122; 1886 (described as ''Calyptraea calyptraeiformis'')

Distribution

This marine species is endemic to

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

References

* Powell A. W. B., William Collins Publishers Ltd, Auckland 1979 * Marshall B.A. 2003. ''A review of the Recent and Late Cenozoic Calyptraeidae of New Zealand (Mollusca: Gastropoda)''. The Veliger 46(2): 117-144

External links

* Calyptraeidae Gastropods of New Zealand Taxa named by René Lesson Gastropods described in 1831 {{Calyptraeidae-stub