I thought they were D. sabina apparently they are
Hypanus sabina. I am not sure if that changed or if I was always wrong. They are an unregulated species in Florida falling under here
"Unregulated" Species | FWC (myfwc.com) Keeping any of the exotic rays is tightly regulated. Many people catch them in the Gulf or Atlantic and try to acclimate them down. From what I have seen this doesn't go well. There were even some fish farmers looking at it as a partnership with commercial fishermen, but ultimately they decided it wasn't worth it. The best known source of these rays is Lake George on the St Johns river. The native rays seem to do better in freshwater if they are collected in freshwater. Lake George has very high mineral content which may help these fish do better. Sometimes it is even considered a brackish lake. I would say if you are keeping them very low levels of salt will help. However, as everyone said they are a large bioload and you need to be prepared for that. Plus they get around 2ft wingspan and are fairly active. So, the bigger the footprint the better.
If none of that interest you then the best way to enjoy them since you are in Florida is take a trip to Lake George. There are some great springs to explore like Silver Glen and you can do some good fishing as well. I haven't done it but there are some houseboat rentals you can take a week and explore the lake.
not my photos
