Thank you for the info. I’ll go pick up an airstone and see if he survives the night. If he does, then I’ll go get the medications that you suggested.So I will backtrack a bit (but only a bit) - on the possibility that the fish was just healthy, swimming around, and got sucked against. If so - I would consider an antibiotic treatment - in a hospital tank - in case of infection after a significant injury. I would be careful about putting a pump in that tank - instead an ayirstone (as someone else suggested). I would say neomycin or kanamycin - but in reality this could be almost anything - parasite or bacteria. Hope this helps. Sorry not to be more specific.