He is not eating and has not for 2 days I can try to catch him and move him. What type of antibiotics?That is a very severe case of "tail rot". In most cases, it is preceded by some damage, either another fish attacking it, or physical damage during shipping. The similar spot showing up on the dorsal fin seems to indicate that the infection is systemic, and travelling through the fish.
Sorry, the prognosis is poor. The hypural plate of the tail is involved, so it is likely the fin won't grow back even if the fish survives.
Is the fish still eating? Do you have the ability to move it to a treatment tank and dose with strong antibiotics?
You should try multiple antibiotics to really hit it hard: Furan-2 plus Neoplex, Maracyn 1 plus Maracyn 2 if you can’t find that. Dose in a treatment tank according to label instructions. Just avoid those herbal remedies, those won’t help in a severe case like this.He is not eating and has not for 2 days I can try to catch him and move him. What type of antibiotics?