I had a nurse shark in a 100 gallon many, many years ago.
I worked a store and somebody orphaned it at the store. I opted to take it until arrangements could be made for him. I ended having him for over 3 months.
It was only done as a last resort. He was about 20" at first and was almost 32" when we finally found him a home at a public aquarium in Tokyo.
The only thing that made it possible is that nurse sharks are relatively sedentary and daily pwc
's, plus about 4x the filtration normally needed for 100 gallons.
But to keep sharks in anything other than a very large and specific tank is not respecting the creatures we enjoy so much.
but as mentioned, lots of rays are suitable for aquarium life.
Also bear in mind that more often than not when you do see sharks in tanks at bars, hotels, wherever, they are being rotated in and out of the tanks and do not live their entire lives in there.
If you do proceed, I fear some other lfs
owner will be having to find a home for an orphaned shark.