After a casual search, apparently there are several names including scientific names available for these snails. There are at least two strains one in China and one in Japan. USGS lists several scientific names for them that are taxonomic synomyms (different names for the same species). Evidently they can consume lots of attached algae per snail probably due to their relative size. The Indiana reports they eat phytoplankton and zooplankton. Attached algae (periphyton) is an important part of the food chain for producing fish biomass.
If you can believe Wikipedia:
http://en.wikipedia.org/wiki/Chinese_mystery_snailUSGS Factsheet:
http://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=1046Some good information from Indiana DNR.
http://www.in.gov/dnr/files/CHINESE_MYSTERY_SNAIL.pdf
