{{Short description|Genus of gastropods}} {{Automatic taxobox | name = ''Nipponacmea'' | image = Nipponacmea fuscoviridis 002.jpg | image_caption = ''Nipponacmea fuscoviridis'' | display_parents = 3 | taxon = Nipponacmea | authority = Sasaki & [[Takashi Okutani|Okutani]], 1993<ref name="Sasaki 1993">{{cite journal|last=Sasaki|first=T.|author2=Okutani T.|title=New genus ''Nipponacmea'' (Gastropoda, Lottiidae): a revision of Japanese limpets hitherto allocated in ''Notoacmea''|journal=Venus, Jap. Journ. Malac.|year=1993|volume=52|issue=1|pages=1–40|url=http://www.um.u-tokyo.ac.jp/hp/sasaki/p/001.pdf|accessdate=2010-07-26|url-status=dead|archiveurl=https://web.archive.org/web/20110716055547/http://www.um.u-tokyo.ac.jp/hp/sasaki/p/001.pdf|archivedate=2011-07-16}}</ref> | synonyms_ref = | synonyms = | type_species = ''Patella schrenkii'' <small>Lischke, 1868</small> }}
'''''Nipponacmea''''' is a [[genus]] of [[sea snail]]s, the [[true limpet]]s, marine [[gastropod]] [[mollusk]]s in the [[Family (taxonomy)|family]] [[Lottiidae]].<ref name="WoRMS">{{WRMS species|391295|''Nipponacmea'' ||13 April 2010}}</ref>
==Distribution and habitat== These species are very common among the Japanese gastropod fauna on rocks and boulders in the [[intertidal zone]] 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 and 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.
==Species== Until 1993 the species of these Japanese limpets were allocated in the genus ''[[Notoacmea]]''.<ref name="Sasaki 1993"/> 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.<ref name="Sasaki 1993"/>
Species within the genus ''Nipponacmea'' include:
* ''[[Nipponacmea concinna]]'' (Lischke, 1870)<ref>{{WRMS species|456611|''Nipponacmea concinna'' (Lischke, 1870)||13 April 2010}}</ref> * ''[[Nipponacmea fuscoviridis]]'' (Teramachi, 1949)<ref>{{WRMS species|456612|''Nipponacmea fuscoviridis'' (Teramachi, 1949)||13 April 2010}}</ref> * ''[[Nipponacmea gloriosa]]'' (Habe, 1944)<ref>{{WRMS species|456613|''Nipponacmea gloriosa'' (Habe, 1944)||13 April 2010}}</ref> * ''[[Nipponacmea habei]]'' (Saski & Okutani, 1994)<ref>{{WRMS species|456614|''Nipponacmea habei'' (Saski & Okutani, 1994)||13 April 2010}}</ref> * ''[[Nipponacmea moskalevi]]'' Chernyshev & Chernova, 2002<ref>{{WRMS species|395579|''Nipponacmea moskalevi'' Chernyshev & Chernova, 2002||13 April 2010}}</ref> * ''[[Nipponacmea nigrans]]'' (Kira, 1961)<ref>{{WRMS species|456615|''Nipponacmea nigrans'' (Kira, 1961)||13 April 2010}}</ref> * ''[[Nipponacmea radula]]'' (Kira, 1961)<ref>{{WRMS species|456616|''Nipponacmea radula'' (Kira, 1961)||13 April 2010}}</ref> * ''[[Nipponacmea schrenckii]]'' (Lischke, 1868)<ref>{{WRMS species|456617|''Nipponacmea schrenckii'' (Lischke, 1868)||13 April 2010}}</ref> * ''[[Nipponacmea teramachii]]'' (Kira, 1961)<ref>{{WRMS species|456618|''Nipponacmea teramachii'' (Kira, 1961)||13 April 2010}}</ref> * ''[[Nipponacmea vietnamensis]]'' Chernyshev, 2008<ref>{{WRMS species|457034|''Nipponacmea vietnamensis'' Chernyshev, 2008||13 April 2010}}</ref>
==References== {{Reflist}}
{{Taxonbar|from=Q7039678}}
[[Category:Lottiidae]] [[Category:Taxa named by Takashi Okutani]]