2-1 to St Louis then. Thanks for the help guys.
But wait
@Brum, there's more!
The Reptile House is hands down my favorite exhibit at Saint Louis and they got very lucky with this category, as I think it's their strongest one (also probably the one with fewest weaknesses). As
@birdsandbats outlined, their collection is very impressive, and including off-display species it's even bigger than that.
A big highlight in my view are their breathtaking collection of pitvipers (certainly one of the largest on the continent, if not *the* largest) with a particular focus on mountain pitvipers. They are one of the leading institutions for conservation work with this group of animals and their work with endangered Armenian vipers is well explained here:
Center for Conservation in Western Asia | Saint Louis Zoo
Another important conservation initiative they do locally is with hellbenders. They were the first facility in the world to breed Ozark hellbenders and are working with Missouri's state government to breed large numbers of them for eventual release. They have a 32-foot long simulated mountain stream behind the scenes in the Reptile House that is used for these breeding purposes. The initiative is explained here:
Ron Goellner Center for Hellbender Conservation | Saint Louis Zoo
They also hold and work with several other interesting and threatened species of herp, such as mountain chicken, tomistoma, Arakan forest turtle as well as several other Asian chelonians, Kaiser's newt, Puerto Rican crested toad, Mangshan pitviper, and Asian narrow-headed softshell turtle.
As for invertebrates, they have done a lot of work with American burying beetles where they are one of only 4 AZA facilities breeding for release. That work is detailed here:
Center for American Burying Beetle Conservation | Saint Louis Zoo. They also breed and maintain two species of Partula snail (nodosa and taeniata), joining only a small number of American zoos that participate in those efforts. As for the insectarium, I have seen both Cincinnati and Saint Louis; while I loved both of their insect houses, I like Saint Louis slightly more because I found more interactive for kids (which is great for an insect house), more creatively designed (Cincinnati feels more like a sterile maze), and they have a very cool view of their behind-the-scenes work through a glass window. You can actually see the containers full of burying beetles and other species they are breeding.
As for fish, that is admittedly not a strong point for Saint Louis. Their Missouri river tank is very cool though, and kudos to them for including it in an exhibit complex that features elephants, rhinos, cheetahs, and other species that the average visitor cares way more about.
I agreed overall with
@snowleopard's analysis, but for now I'm voting 3-0 for Saint Louis because Saint Louis's weakness on fish isn't enough to pull it down to a 2-1 vote for me. That being said, I haven't been to Frankfurt and don't know much about it so I could potentially be persuaded to grant it a point.
