The freshwater Yamato shrimp, Caridina japonica, made popular by aquascaping guru Takashi Amano has been given a new scientific name.
A team of scientists from the National University of Singapore, the University of the Ryukyus and the National Institute for Environmental Studies studied six species of Japanese shrimp in the Atyidae genus Caridina and have renamed the popular Yamato or Amano shrimp, as Caridina multidentata.
Their findings, which are published in the latest issue of the Journal of Crustacean Biology, are based on a detailed study of the species described by William Stimpson in 1860 and include new data from fresh specimens collected at the type localities the original shrimps were collected from.
Caridina japonica was described in 1892 by De Man, however, the study says that this species is the same as Caridina multidentata, which Stimpson described 32 years earlier in 1860. As a result, Caridina multidentata is a senior synonym of Caridina japonica, so the newer name - japonica - has been dropped and the Amano shrimp is now called C. multidentata.
The species is said to live in large rivers with big rocks as the substrate - not in densely planted areas. It has been recorded from the main islands of Japan, Ogasawara Islands, Ryukyu Islands, Taiwan, Fiji and Madagascar.
Caridina grandirostris, which was previously believed to be a synonym of Caridina longirostris has been shown to be a distinct species. Caridina acuminata and C. brevirostris were both found to be junior synonyms of a shrimp in a different genus - Atyoida pilipes, and similarly C. exilirostris is the same species as C. typus.
The authors have created a new series of neotypes, redescribed the shrimps and redrawn their anatomy to help scientists accurately identify them when undertaking further work in the future.
For more information on the shrimp study see the paper: Cai Y, Ng PKL, Shokita S and K Satake (2006) - On the species of Japanese atyid shrimps (Decapoda: Caridea) described by William Stimpson (1860). Journal of Crustacean Biology, 26(3); 392-419, 2006.