please return this fish and get something more suitible for your tank size.
the wobbegong gets about 8 feet, dont know much about the string ray but they need a large surface area on the sand, not sure about the puffer or other shark either but imagine the shark gets huge too.
please either purchase the proper size aquarium or return these fish for credit and get something you can properly keep.
Wow. Please don't take these comments to be rude or obtrusive, as everyone here means well. But I agree with OF2F, your take is one of the most overstocked abusive situations that I have ever seen in my 20 years of marine fishkeeping. The animals in this tank have almost no chance of surviving any reasonable period of time.
You have to understand that fish have a certain minimal growth rate which must be allowed for. If not allowed proper room, they will not develop properly. You have a small aquarium by marine standards and have no justification for keeping fish that need 400 or more gallons of space, even as juveniles.
This is starting to sound like a rant, I know. But these sort of decisions is what will eventually cause our hobby to be the target of lobbyists who CAN'T WAIT to get the political environment to regulate our hobby. You are contributing to what will one day to a justifiable frenzy of regulation aimed at preventing the collection of marine species.
All this being said, I have no idea your experience level. I am hoping that you were completely misinformed by the LFS and that you want to be a responsible and successful fishkeeper. This is not a personal attack, just an attack on the LFS that allowed the sale of these fish. We would love to help you right this situation if you can provide some details on your aquarium(s).