Current emerging diseases afflicting the ornamental fish industry

Authors: Shelley, John; YANONG, ROY - University Of Florida

Submitted to: Book of Abstracts World Aquaculture Society
Publication Type: Abstract Only
Publication Acceptance Date: 2/12/2019
Publication Date: 3/7/2019
Citation: Shelley, J.P., Yanong, R.P. 2019. Current emerging diseases afflicting the ornamental fish industry. Book of Abstracts World Aquaculture Society. p.1000.

Interpretive Summary:

Technical Abstract: The ornamental fish industry is unique in that it includes both domestic culture and international trade of over 2,500 species from more than 125 countries. Environmental challenges, heavy stocking densities, improper nutrition and transport stress can facilitate infectious disease. Various diseases of concern with widespread financial implications have cropped up over the years, but through veterinary involvement the ornamental aquaculture industry has been able to identify, characterize and address many of these issues. However, “new” pathogens or the reemergence of pathogens once considered to be under control continues to be a problem that plagues the industry. Spironucleus vortens and Cryptobia iubilans are two flagellated protists that are best known for causing disease in African and South American cichlids. Treatment protocols have been established for these parasites, but evidence suggests that resistance may be an increasing issue and reevaluation of treatment regimens is warranted. Since 2011, a new strain of Edwardsiella ictaluri has emerged as a significant bacterial pathogen of zebrafish and other ornamental cyprinids. Currently, research is focusing on genetic profiling of this zebrafish E. ictaluri strain and evaluation of the effectiveness of different disease management strategies. Since 2012, low to moderate mortality associated with Erysipelothrix sp. bacteria which cause a severe ulcerative stomatitis has been reported in multiple cyprind and characin species. Research is focusing on characterizing the bacteria in an effort to produce an effective vaccine for the ornamental fish industry. Carp edema virus disease (CEVD), also known as “koi sleepy disease,” is a re-emerging viral disease of koi and common carp. Research is still needed to determine factors that precipitate disease, the length of time the virus remains infectious in the water, if the virus can be spread through vertical transmission and whether survivors clear the virus or become carriers. Megalocytivirus, an important genus of the family Iridoviridae can infect many different freshwater and marine fish species. Strains of Megalocytivirus are currently divided into three major subgroups: 1) infectious spleen and kidney necrosis virus (ISKNV); 2) red sea bream iridovirus (RSIV); and 3) turbot reddish body iridovirus (TRBIV). Historically viral strains reported in ornamental fish most closely resembled ISKNV, but recent research indicates that some of these isolates more closely resemble TRBIV. Herpesviruses are a poorly studied group that may have been the cause of major historical mortality events. Clinical signs are non-specific and fish present similarly to those infected with Megalocytivirus. Validated detection methods, surveillance programs, and prevention and management strategies are still needed.