I totally agree that the importer should never have sent them to the shops - there is no way they would have thought they were loaches when they saw them.
But the shops have a responsibility too - I don't believe that any shop who sold these really thought they were loaches - if they did I'm sorry but I find it pretty unlikely.
If that is the case, and they sold them knowing they were some type of eel (which is, as well all know, pretty obvious!), then I think they should face up to the fact that when the crap hits the fan - they are the ones responsible for stopping new invasive species from getting into the country.
It doesn't seem like many are taking this responsibility very seriously...
Well done to your hubby though Afrikan