<a href=showthread.php?s=&postid=9472933#post9472933 target=_blank>Originally posted</a> by Slakker
Which is all fine and dandy as long as you know what you just got....but for the hobbyist who wouldn't necessarily notice a difference or know better, that could be disaster.
Say a newbie aquarist receives a pair of A. Latezonatus when they thought they were getting A. Polymnus (or they thought they were getting the mythical "Black Percula"). This newbie happens to take real good care of their tank, everything is going good, his little chitlins (the fish...not actually his kids...) start breeding. Jimmy the Aquarist here now believes he's got a pair of breeding "Black Perculas", he tries his hand at raising the fry, has a few work out here and there, and sells them to his LFS. Now his LFS has a fairly regular supply of A. Latezonatus, but they think it's "Black Perculas."
Or maybe a new aquarist buys a single A. Polymnus as his first fish, and since it was labelled as "Black Percula" the poor guy tries to pair it up with a legitimate A. Percula. I'm sure we can all agree that A. Polymnus is more...assertive...than A. Percula, so this guys ends up with dead fish after dead fish, and can't understand why his "Black Percula" keeps killing off his "True Percula" clowns. They're the same species, after all, right?!
Also, in response to the Freshwater "sharks" comment...That's really, really different. "Shark" is not the scientific name of any specific species of shark, merely the common name for a whole family of fish. I think the odds of someone getting a Rainbow Shark confused for an actual shark are pretty slim (i'll admit when I was younger I told everyone we had a shark in our aquarium, but I also told everyone we drove a Lamborghini because I couldn't remember that it was a Pontiac...). In this case, the odds of someone getting confused by the "Black Percula" title is really, really high, and this confusion can cause some potentially serious problems. That's why I feel it's so important to get this right and to make the correction when we see it wrong.