The citrinellus complex has been in the realm of the "Splitters" over the last few years. Barred Midas can refer to many similar fish now that the complex has been split up so much.
As for flaveolus, it is only found in Lago Apoyo, a crater lake in Nicaragua. The basic story with this and several of the "new" species is they have all arisen from a basic citrinellus type which became isolated in a crater lake. In an example of convergent evolution, each of these crater lakes has seen the evolution from the basic citrinellus into a few very similar but distinct species.
For instance, Lago Xiloa has A. amarillo (a citrin-like invertebrate feeder). Lago Apoyo has the very similar A. flaveolus. Xiloa has the elongated, piscivorous zaliosus while Apoyo has the very similar sagittae. Then same story is repeated several times over, but all of these species evolved from the basic citrinellus type into a distinct species with a specialized feeding adaptation.
At the end of the day, with the exception of zaliosus, sagittae, and most labiatus the average guy won't be able to tell much of a difference between many of these fish until they are fully grown, and even then you'd have to know the collection location to identify some species.
