3. Tank mates: Anything with long flowing fins, Crayfish, even smaller ornamental shrimp are a no go imo with dwarf puffers, cray fish as mentioned could hurt / kill the puffers, and any fish with long flowing fins will definitely get nibbled on... The ornamental shrimp in my own experience has been touch and go, coz once they learn that they can eat the shrimp, then they will start to target them and take them down... Otos on the other hand might work, but may still end up with a few torn fins, same with the pleco...
Just wanted to add the bolded part to make sure the post was more clear
