Do folks realize that this place imports the fish from the wild? I would expect newly caught and shipped fish would need to be medicated. These fishes are straight from the ocean. I'm not sure if it is actually methylene blue, or not. Here's what I learned from the interwebs about it...Methylene Blue is also very effective when used as part of a "medicated fish bath" for treatment of ammonia, nitrite, and cyanide poisoning as well as for topical and internal treatment of injured or sick fish as a "first response. i once asked a guy what the "blue" was and he said it was to help the fish breath better after being shipped.