I think that these are 'electric blue acaras'. I believe that they are aquarium-bred hybrids, or perhaps mutations, with the wild-type blue acara (Andinoacara pulcher) as one of the parents. I disapprove of keeping hybrids like these in public collections when there are so many rare and beautiful wild species that could be kept.
Yep, these are aquarium-strain Blue Acara. I share @gentle lemur 's sentiment about aquarium-strain fish in public aquariums, they make the displays look more like a pet shop than an aquarium!
These are not hybrid fish, just selectively bred Blue Acara for a metallic blue colouration. Gorgeous fish, but they have no place in a public aquarium.
