Probably because the saying that angels eat fish lice remains circulated around. Typical indeed because most of the myths circulated locally must have happened coincidentally or because we tend to think it did happen even though there's no certainty it did. One store had both angels and goldfish mixed and the angels were harassing the poor goldies around.
Hmmm...I wonder if they still have the electric eel there? I visited it three times already and on those visits, I always make sure to take a brief glance on the electric eel.
I was able to witness a shark egg developing in one tank last December 2008 I think. It was fascinating even though sharks are not my specialty nor something I ever studied indepth.