After reading about the medicine he used I would say it is fairly certain the medicine itself killed the ray
It says that it can be harmful if used on stressed or weakened fish and is best used as a topical treatment or dip
Neomycin
Active ingredients: 200 mg, Neomycin Sulfate
Diseases: internal swelling, open sores, body and fin rot, colour and weight loss, wasting away
Contraindications:
This affects the bacterial cell membrane which is responsible for bringing nutrients into the cell and taking waste out of the cell. The antibiotics disrupt this process. It is toxic when overdosed and fatal to already weakened fish.
I agree I think that one is not raysafe. A good raysafe antibiotic medication is Nifurpherinol still treated with care. The main source of bacterial problems is stress, it weakens the fishes immune system than pathogene bakteria can spread in the organism of the fish. If compared to us humans if we have a fluh and we dont get warm and dry this flu turns into a plumonia which untreated is deadly. So in the fluh stage the ray can be helped! The ray shows thru its behaviour a bacterial infection, in the plumonia stage before the ray is allready curling no medication can help, because any stress on the fish will kill it. As a post before only good waterquality can turn the cycle backwards.
These antibiotics prevent protein synthesis and effect the cells ability to reproduce. Also a very powerful antibiotic that often is not resisted by various strains of bacteria making it the last but great choice for severe bacterial infections.
Best used as a bath/dip or topical treatment.
Dosage courtesy of
Thegab.org:
1/4 of the package to a quart of distilled water placed in a ziplock freezer bag. Place the fish in the mixture for at least 5 minutes. Remove if fish is very distressed and cease continuation. Once the dip is done, put the fish in a separate container for a brief period (preferably 10-15 minutes) to rinse most of the antibiotic as Neomycin can destroy beneficial bacteria.