Linnaeus described these in 1754 but did not publish until 1759 while a description (with no types) was published a year earlier.

In 2008 it was looked at and it would seem because the species differ in minute differences like otoliths, unknown in Linnaeus time, and given the species are found together in the type locality, there really was no way for Linneaus to know which one he had and no way to tell which one is actually M opercularis, one of the oldest known captive aquarium fishes. They've been in culture in Asia for we don't know how long. 500 years? 1000 years, 5000 years?