Mystery Snails

Pomacea diffusa was originally described as a subspecies of Pomacea bridgesii. Pain (1960) argued that Pomacea bridgesii bridgesii was a larger form with a restricted range, with the smaller Pomacea bridgesii diffusa being the common form throughout the Amazon Basin (Brazil, Peru, Bolivia). Cowie and Thiengo (2003) suggested that the latter might deserve full species status, and the two taxa have been confirmed as distinct species by genetic analyses.