Cecina is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of sea snail

Sea snail

Sea snail is a common name for those snails that normally live in saltwater, marine gastropod molluscs....

s which have a gill

Gill

A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...

 and an operculum

Operculum (gastropod)

The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...

, gastropod mollusks or micromollusk

Micromollusk

A micromollusk is a descriptive term for a shelled mollusk which is extremely small, even at full adult size. The word is usually, but not exclusively, applied to marine mollusks, although in addition, numerous species of land snails and freshwater mollusks also reach adult size at very small...

s in the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Pomatiopsidae

Pomatiopsidae

Pomatiopsidae is a family of small mainly freshwater snails with gills and an operculum, aquatic gastropod mollusks in the superfamily Rissooidea ....

.

They live in shallow waters in littoral

Littoral

The littoral zone is that part of a sea, lake or river that is close to the shore. In coastal environments the littoral zone extends from the high water mark, which is rarely inundated, to shoreline areas that are permanently submerged. It always includes this intertidal zone and is often used to...

 and supralittoral habitats.

Distribution

The distribution of the genus Cecina includes the Sea of Japan

Sea of Japan

The Sea of Japan is a marginal sea of the western Pacific Ocean, between the Asian mainland, the Japanese archipelago and Sakhalin. It is bordered by Japan, North Korea, Russia and South Korea. Like the Mediterranean Sea, it has almost no tides due to its nearly complete enclosure from the Pacific...

 in Primorsky Krai

Primorsky Krai

Primorsky Krai , informally known as Primorye , is a federal subject of Russia . Primorsky means "maritime" in Russian, hence the region is sometimes referred to as Maritime Province or Maritime Territory. Its administrative center is in the city of Vladivostok...

, Russia, Japan and Washington State, USA.

Species

In 1861, Arthur Adams

Arthur Adams (zoologist)

Arthur Adams was an English physician and naturalist.Adams was assistant surgeon on board H.M.S. "Actaeon" in company with HMS Samarang in the British Navy during the survey of the Malay Archipelago, the Japan Sea, Korea and China,from 1843 to 1846. He edited the Zoology of the voyage of H.M.S....

 described the genus Cecina as a monotypic genus with Cecina manchurica

Cecina manchurica

Cecina manchurica is a species of sea snail that has a gill and an operculum, a marine gastropod mollusk in the family Pomatiopsidae.The specific name manchurica refers to Manchuria, the historical region where its type locality was situated....

as the only species.
The current classification of Cecina follows Davis (1979) and other authors.

In 1996, Larisa A. Prozorova reviewed the genus, described 6 new species of Cecina and re-established Cecina tatarica as a separate species.

The are eight species within the genus Cecina:

• Cecina alta Prozorova, 1996
• Cecina elenae Prozorova, 1996
• Cecina kunashirica Prozorova, 1996
• Cecina manchurica
  Cecina manchurica
  Cecina manchurica is a species of sea snail that has a gill and an operculum, a marine gastropod mollusk in the family Pomatiopsidae.The specific name manchurica refers to Manchuria, the historical region where its type locality was situated....
  
  A. Adams, 1861 - type species
• Cecina murshudovi Prozorova, 1996
• Cecina satrae Prozorova, 1996
• Cecina scarlatoi Prozorova, 1996
• Cecina tatarica (Schrenck, 1867)