I wrote a computer program called
FishBase Client that helps you do searches by genus and common name much more quickly than the Fishbase site. So if you type in
Pseudotropheus, for example, on the Genus (Strict) tab, you'll get all the different species for which that's the currently recognised name. It's pretty good with synonyms, too. Type
Pseudotropheus zebra on the Species tab and you go straight to that fish's page, even though the current name is
Maylandia zebra. You could also use the plain Genus tab for
Cichlosoma and get all the fishes included under than name either currently or in the past. There's a Common Name tab, into which you might type "angelfish" and get all the different fishes with that as part of their common name. The Family tab is useful for finding out information on fish families or trying to identify something using the thumbnail view in Fishbase. It's for Macintosh and Windows, and is free.
Generally, I wouldn't trust an aquarium store that didn't know the Latin name. This is especially true with fishes likely to hybridise, like rare livebearers and mbuna. Right now, I'm into halfbeaks, and finding that it is more than possible to have three different species being sold in a single batch of "Celebes halfbeaks", and two different
genera being sold as something like "golden halfbeaks"!
As a total aside, there's an excellent book called
Botanical Latin that you might be able to borrow from a library. It helps you understand what all the different words mean. There's actually some art to many Latin names.
Pterophyllum scalare, for example, means
wing-leaf, like a flight of stairs, the first part a reference to the dorsal and anal fins, and the second part to the step-like arrangment of spines at the front of the dorsal fin.
Cheers,
Neale
if you go to
fishbase.org
you can search for the common or SN.