The pink-lipped topshell (''Oxystele sinensis'') also known as the rosy-base topsnail, 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), ...

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 ...

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

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 ...

Trochidae The Trochidae, common name top-snails or top-shells, are a family of various sized sea snails, marine gastropod molluscs in the subclass Vetigastropoda. This family is commonly known as the top-snails because in many species the shell resembles ...

, the top snails.

Description

The pink-lipped topshell has monomorphic purplish-black shell with a crimson inner lip. The shell in adults is between 18 mm and 51 mm.

Distribution

This marine species occurs from

False Bay False Bay (Afrikaans: ''Valsbaai'') is a body of water in the Atlantic Ocean between the mountainous Cape Peninsula and the Hottentots Holland Mountains in the extreme south-west of South Africa. The mouth of the bay faces south and is demarc ...

to South

Transkei Transkei ( , meaning ''the area beyond Great Kei River,

he river The He River is a tributary of the Xi River in Guangxi and Guangdong provinces in China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it ...

Kei''), officially the Republic of Transkei (), was an list of historical unrecognized states and dependencies, unrecognised state in the southeastern region of South Africa f ...

near the

Mbashe River Mbhashe River is one of the major rivers in the Eastern Cape Province, South Africa. It flows in a southeastern direction and has a catchment area of 6,030 km. The river drains into the Indian Ocean through an estuary located near the ligh ...

, South Africa.

Ecology

Especially small individuals of this species that live in the

intertidal zone The intertidal zone or foreshore is the area above water level at low tide and underwater at high tide; in other words, it is the part of the littoral zone within the tidal range. This area can include several types of habitats with various ...

are predated upon by rock lobsters. Larger individuals largely escape this predator by migrating to deeper waters, where they find a size refuge.

References

External links

* Endemic molluscs of South Africa sinensis Gastropods described in 1791 Taxa named by Johann Friedrich Gmelin {{Trochidae-stub