When I lived in the US, I did visit aquarium shops from time to time, and one thing that did strike me was that the bulk of the demand seemed to be for "fancy" versions of things: livebearers, hideous angelfish varieties, veiltail oscars, parrot cichlids, albino catfish, and so on. While we have those things here, too, the demand isn't quite so great, so you see fewer varieties. It's quite rare, for example, to see the particular strains of angelfish, and instead you seem to see merely mixed batches of generic marble and golden angelfish.
I think by contrast the English have a thing about cichlids and catfish, often to the point of even small stores selling inappropriate species for most aquarists, such as large predatory catfish or "mixed" African cichlids of unknown (and likely impure) species heritage. On mainland Europe, particularly in Germany and Scandinavia, small wild-caught fishes are very popular, things like unusual tetras and killifish, and in Japan aquarists regularly have access to dozens of species of goby that I've never even seen, let alone kept.
Each country has its strengths and weaknesses, and comparing aquarium shops when you go travelling is very entertaining. What's ironic is that the same exporter countries are supplying each of them -- it's just the different markets demand different things.
Cheers,
Neale
Sounds like the LFS in the UK are just crawling with flatfish. I have been looking around the Southern California, USA area for months for a Trinectes maculatus with absolutely no luck...
