Tennessee Aquarium has lemurs and it's one of the Top 5 aquariums in the country. Florida Aquarium has lemurs and it's one of the Top 20 aquariums in the nation. South Carolina Aquarium had lemurs when I was there in 2012 and Maritime Aquarium in Connecticut had Meerkats when I visited in 2012. You never know what will pop up!
Also, Burgers' Zoo in the Netherlands recently added a walk-through, outdoor lemur habitat to its vast aquarium building. People love lemurs...although having them in aquariums does seem rather silly.
Just because people like them doesn't mean they should have them! I have no problem with adding land mammals that regularly use aquatic habitats (such as raccoons along a stream), but ring-tailed lemurs that are not aquatic at all is just (as my friend says) silly.
