Suckermouth wrote:If Jon Armbruster can't identify them well, you can bet that the people who are using his key to identify invasive fish aren't going to be doing much better.
And that is if they are using a key at all, rather than some book that they found in the local library or some such. If you are not aware that there is a dozen (give or take) species of Pterygoplichthys, and about 700 different other plecos, it is fairly easy to jump to the conclusion that the first pleco you find in a book is the one you are looking at - after all, they are quite different from all the other fishes that we find in generic aquatic species books. I have an old aquarium book. It's a Swedish translation of "Freshwater tropical fishes", John Gilbert (editor), et. al. from 1970. It has exactly four species of of Loricariidae:
Farlowella acus,
Otocinclus flexilis,
Plecostomus punctatus and
Xenocara dolichopterus (that's the names GIVEN in the book, I'm not saying they are completely correct - the X. dolichopterus definitely look like the true
, but the remainder could be any of the common fishes sold under these names).
Now, in a more modern book, there may be another few species, and one of them may be a Pterygoplichthys. And if it's not too far off, it will probably be taken as "that's the one".
I'm not saying the people who are doing this sort of research are incompetent as such, but we here at Planet Catfish tend to be VERY specialized in catfish, and have several books about this subject alone. We will take a tiny difference between two fishes and try to figure out if that makes it a different species or not.
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Mats