Abstract: The present disclosure provides an immersion vaccine for fish comprising at least one isolated antigen, specifically a recombinant antigen, such as is F. psychrophilum and/or infectious pancreatic necrosis virus (IPNV).

Abstract: Methods of producing, propagating and multiplying viruses, methods of identifying the presence of a virus in a sample, specifically methods using Japanese eel cell cultures. Also provided are an isolated Japanese eel cell culture, optionally infected with a virus, vaccines comprising viruses grown according to the methods of the invention, and a kit for propagating viruses comprising the Japanese eel cell culture. The virus may be a fish virus such as nodavirus, Infectious Pancreatic Necrosis Virus (IPNV) and Salmon Pancreas Disease Virus (SPDV).

Abstract: The present disclosure relates to treatment of chitin-containing microorganism infection or colonization on an aquatic animal. The methods, systems, and kits provided herein facilitate termination and/or inhibition of proliferation of chitin-containing microorganisms (e.g., Saprolegnia and sea lice).