Jenny - an aquarium linebred mutation or hybrid is never a species. I'm talking about distinct species found in nature, backed up by DNA and what we can see with dissection, that vary enough to be 'real' species. I'm just a fish guy with friends, not a scientist myself, but this hobby really lets me follow my curiosity.
For example, with our beloved Corydoras, I've spoken with researchers who say almost every notable stream has its own Cory. Scotcat is a Scottish site that looks at catfish, and if you go to 'identicat' on their site, then click on 'CW numbers', you'll see a lot of the Cory species with no names yet, but that have been imported from the wild.
They're just one example.
Lake Mweru in the Democratic Republic of Congo is a recent example of 'new" (to us) Cichlids. I've kept 3 of them, and they're neat fish. A bit rowdy and hard to tell apart without DNA work, but cool little mouthbrooders. I have a Steatocranus here from the buffalo-head group that doesn't fit anyone's picture of the group - a pleasant little (grey) fish.
As people begin to take rainbows out of Papua-New Guinea, the number (and beauty) of the new finds is jaw dropping.
When I was a kid, my fishbook said there was Corydorus aeneus, melanistius, julii and paleatus, and that was all. Guess it wasn't....
