Yamato shrimp is now Caridina multidentata

**hwchoy** · 18th Sep 2006, 00:36

In the paper just published, Cai Y.X. et al has established that Caridina japonica is a junior synonym of Caridina multidentata Stimpson, 1860.

JOURNAL OF CRUSTACEAN BIOLOGY, 26(3): 392–419, 2006

ON THE SPECIES OF JAPANESE ATYID SHRIMPS (DECAPODA: CARIDEA) DESCRIBED BY WILLIAM STIMPSON (1860)
Yixiong Cai, Peter K. L. Ng, Shigemitsu Shokita, and Kiyoshi Satake

ABSTRACT

The taxonomic status of the six Japanese species of Caridina described by W. Stimpson (1860) is clarified on the basis of fresh specimens from the type localities. Caridina grandirostris, which has long been synonymized under C. longirostris H. Milne Edwards, 1837, is shown to be a distinct species; C. leucosticta is redescribed; C. multidentata is the senior synonym of C. japonica De Man, 1892; C. acuminata and C. brevirostris are regarded as junior synonyms of Atyoida pilipes (Newport, 1847); and C. exilirostris is synonymized with C. typus H. Milne Edwards, 1837. Neotypes for the six species are designated to stabilize their taxonomy, all of which are redescribed and figured. The various nomenclatural problems associated with these species are discussed.

**budak** · 18th Sep 2006, 09:23

so where the type locality for the shrimp formerly known as japonica?

**hwchoy** · 18th Sep 2006, 10:59

original type locality of C. multidentata - Caridina multidentata Stimpson, 1860: 98 [type locality: Ogasawara (Bonin) Islands, Japan].

Neotype of Caridina multidentata: ovigerous female, cl 9.8 mm, NSMT, from a stream in Tenno-ura, Chichi-jima Island, Ogasawara Islands, coll. K. Satake and H. Suzuki, 4 May 2000.

**hwchoy** · 18th Sep 2006, 16:58

for those people who "caught no ball" here's a translation by James of South Africa

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[the species names should be in italics, but I'm being lazy]
Caridina grandirostris ("big nose") has been called C. longirostris for a long time. The two are now considered separate species.

C. leucosticta (btw "sticta" means "spotted"; leuco- usually means yellowish) has been given a new coat of paint (redescribed means the old description of what determined the species was a little wishy-washy and has been tidied up and made more detailed and diagnostic).

They decided that C. multidentata ("many-toothed" proably referring to the rostrum) and C. japonica (from japan) were actually the same species. Because C. multidentata is the older name, it gets kept whilst the younger (junior) name becomes a synonym, leaving, for the moment, C. multidentata as the correct name.

C. acuminata ("pointy" or "sharp"), C. brevirostris ("short nose") and Atyoida pilipes are considered to be all the same species; the oldest name is Atyoida pilipes, so they are now called that.

C. exilirostris and C. typus are considered to be the same species, and will be called C. typus.

A neotype is a new specimen designated to "carry the name" - if in the future, someone comes along and thinks they have found two (or more) species in one of the previous ones, they can examine these type specimens to determine which of the two forms should be called by the existing name and which one gets a new name (or resurrects an old one). Neotypes are only designated when there is no known type material or the types have been lost. types of types.

Taxonomy is quite dynamic at times, which surprises people.

Hope that was understandable

**|squee|** · 18th Sep 2006, 17:29

So in short er, the Yamato shrimp we all know and love has a scientific name of C. multidentata now?

**hwchoy** · 18th Sep 2006, 17:42

yes yes yes.

**budak** · 25th Sep 2006, 23:21

choy, please email me the paper leh.

To add to this confusion, it has also been revealed that the shrimp that you think is Yamato (aka C. multidentata) may not be bona fide Yamatos at all. There are apparently a number of very similar shrimp (with similar flank markings and all) which only an expert eye can tell apart (using features such as the length of the rostrum [nose] and presence of serrations). The existence of these 'sister' species with perhaps habits and dietary preferences different from C. multidentata may explain why some batches of 'Yamatoes' purchased don't seem to like eating algae much, as well as the disparity in full grown size that different shrimp populations (from tank to tank) attain.

**hwchoy** · 26th Sep 2006, 01:02

budak, are you confusing malayan with yamato?

**dc88** · 14th Oct 2006, 19:34

Caridina japonica is now called Caridina multidentata.

http://www.practicalfishkeeping.co.u....php?news=1078

NUS scientists were part of the reseatch team in the renaming.