Nipponacmea
Encyclopedia
Nipponacmea is a genus
of sea snail
s, the true limpets, marine gastropod mollusks in the family
Lottiidae
.
of Japanese waters and adjacent islands.
The color of the shell is greenish brown and characteristically bedecked with granules of fine radial riblets. . The interior is greenish blue and has a shining luster. The thin an broad interior shell margin exhibits a distinct color and texture from the adjoining area.
The shell is constituted of five layers of different structure, while the genus Notoacmea has six layers.
The gill
is flaplike with a bipectinate ctenidium situated in the nuchal cavity and lacks secondary pallial gills. The radula
has typically three pairs of lateral teeth and one pair of marginal teeth that is either lacks any function or is degenerated with growth or is lacking from the beginning.
. They were reassigned based on different anatomical characters and shell structure and their endemism to the Japonic zoogeographical province (Japanese waters and adjacent island chains). There wasn't just enough similarity with the New Zealand
species from Notoacmea. Also the radula
characters were different. Lindberg (in 1986) had pointed out that the genus Notoacmea was restricted to species from New Zealand and Australia and that the North American species belonged in Tectura
. The eight Japanese species had been unsettled until this study. Some authors consider them color variations, others regard them as subspecies or as independent species.
Species within the genus Nipponacmea include:
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, the true limpets, marine gastropod mollusks 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...
Lottiidae
Lottiidae
Lottiidae is a family of sea snails, specifically true limpets, marine gastropod mollusks in the superfamily Lottioidea and the clade Patellogastropoda .- 2005 taxonomy :...
.
Distribution and habitat
These species are very common among the Japanese gastropod fauna on rocks and boulders in the intertidal zoneIntertidal zone
The intertidal zone is the area that is above water at low tide and under water at high tide . This area can include many different types of habitats, with many types of animals like starfish, sea urchins, and some species of coral...
of Japanese waters and adjacent islands.
Description
The shape of the thin shell is limpet-like or patelliform. It has a medium size and has a low to medium height. The base (the aperture) has an oval shape and is longer than wide.The color of the shell is greenish brown and characteristically bedecked with granules of fine radial riblets. . The interior is greenish blue and has a shining luster. The thin an broad interior shell margin exhibits a distinct color and texture from the adjoining area.
The shell is constituted of five layers of different structure, while the genus Notoacmea has six layers.
The 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...
is flaplike with a bipectinate ctenidium situated in the nuchal cavity and lacks secondary pallial gills. The radula
Radula
The radula is an anatomical structure that is used by molluscs for feeding, sometimes compared rather inaccurately to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus...
has typically three pairs of lateral teeth and one pair of marginal teeth that is either lacks any function or is degenerated with growth or is lacking from the beginning.
Species
Until 1993 the species of these Japanese limpets were allocated in the genus NotoacmeaNotoacmea
Notoacmea is a southern genus of true limpets, marine gastropod molluscs in the family Lottiidae, the true limpets.-Species:According to the World Register of Marine Species , the following species with accepted names are species within the genus Notoacmaea:* Notoacmea alta Oliver, 1926* Notoacmea...
. They were reassigned based on different anatomical characters and shell structure and their endemism to the Japonic zoogeographical province (Japanese waters and adjacent island chains). There wasn't just enough similarity with the New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
species from Notoacmea. Also the radula
Radula
The radula is an anatomical structure that is used by molluscs for feeding, sometimes compared rather inaccurately to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus...
characters were different. Lindberg (in 1986) had pointed out that the genus Notoacmea was restricted to species from New Zealand and Australia and that the North American species belonged in Tectura
Tectura
Tectura is a genus of sea snails, true limpets, marine gastropod mollusks in the family Lottiidae. - Species :Species in the genus Tectura include:* Tectura antillarum * Tectura depicta...
. The eight Japanese species had been unsettled until this study. Some authors consider them color variations, others regard them as subspecies or as independent species.
Species within the genus Nipponacmea include:
- Nipponacmea concinnaNipponacmea concinnaNipponacmea concinna is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Lottiidae, one of the families of true limpets....
(Lischke, 1870) - Nipponacmea fuscoviridisNipponacmea fuscoviridisNipponacmea fuscoviridis is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Lottiidae, one of the families of true limpets.-Distribution:...
(Teramachi, 1949) - Nipponacmea gloriosaNipponacmea gloriosaNipponacmea gloriosa is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Lottiidae, one of the families of true limpets....
(Habe, 1944) - Nipponacmea habeiNipponacmea habeiNipponacmea habei is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Lottiidae, one of the families of true limpets....
(Saski & Okutani, 1994) - Nipponacmea moskaleviNipponacmea moskaleviNipponacmea moskalevi is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Lottiidae, one of the families of true limpets....
Chernyshev & Chernova, 2002 - Nipponacmea nigransNipponacmea nigransNipponacmea nigrans is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Lottiidae, one of the families of true limpets....
(Kira, 1961) - Nipponacmea radulaNipponacmea radulaNipponacmea radula is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Lottiidae, one of the families of true limpets....
(Kira, 1961) - Nipponacmea schrenckiiNipponacmea schrenckiiNipponacmea schrenckii is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Lottiidae, one of the families of true limpets....
(Lischke, 1868) - Nipponacmea teramachiiNipponacmea teramachiiNipponacmea teramachii is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Lottiidae, one of the families of true limpets....
(Kira, 1961) - Nipponacmea vietnamensisNipponacmea vietnamensisNipponacmea vietnamensis is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Lottiidae, one of the families of true limpets....
Chernyshev, 2008