Shedd Aquarium Brackish Fish in freshwater?

[Loganfish]

Hello! Last year I went on a trip with my mom to Chicago and we went to the Shedd Aquarium. While I was there, I saw that several of their tanks had brackish fish in with freshwater fish. The main two examples being: (Mono Sabae with Congo Tetras and Dist. Sexfaciatus(?), and (African Tiger Scats with Green Chromide (I think) and WA Lungfish. Any ideas on how they do this? Light brackish? Perhaps some of these fish can tolerate those salinities and sg’s? They also have a full saltwater tank with (Mono Argentus, Ruby/Green/Common Scats, Archerfish (also in freshwater tanks), and more. Any ideas?

 

[Morti]

The simple answer is that they are fine in freshwater as juviniles but they generally do better in higher salinity as they mature. The mono's have probably been moved into the full strength seawater as they have grown and this is what many of these species do in nature, moving from estuaries out into the ocean. Some can move back and forth, so are particularly adaptable. With tiger scats I've seen them live full time in freshwater.