The discovery of P. progenetica, with a mature female of
just 7.9 mm and a maximum size of 10.3 mm, makes it the
smallest recorded vertebrate species, slightly smaller than
the marine goby T. nanus. Paedocypris micromegethes, the
females of which mature at 8.8 mm (maximum 11.6 mm),
comes a close second as the smallest freshwater vertebrate.