I have looked into it and decided it’s not practical. TSA has guidelines that permit live fish and coral as carry-on, but not in checked luggage. The complication is the airline has to permit it, and that is my biggest problem. Delta, United, and Southwest do not allow fish or corals in the cabin. I decided shipping the fish or corals via Fedex or UPS is best for me. An alternative is air cargo.
Way back in 2003, I brought a dozen aquacultured clams back from Palau, as a carry-on. Ran into some problems in Honolulu, but finally got them through. Those days are gone, I think.