Diseased Asian sea bass with clinical signs such as body discoloration, ulceration and hemorrhage at the base …Read More
MANGALURU: The department of Aquatic Animal Health Management (AAHM) in the College of Fisheries, Mangaluru has detected a new viral disease in Asian sea bass, hitherto unknown in Indian waters.
The fish were infected with Red Sea bream Iridovirus (RSIV), which was first observed in Japanese cultured red sea bream farm in 1990’s.
Dr A Senthil Vel, Professor and Dean (Fisheries), Karnataka Veterinary, Animal and Fisheries Sciences University, Mangaluru said that in the year 2018-19, fish farmers in Udupi region informed about mortality of Asian Sea bass (Lates calcarifer) grown in cages. The disease affected fishes exhibited abnormal behavior and clinical signs including slow-moving, lethargy, reduced feeding, erratic movement along the sides of the cages.
Pathologists from the College collected samples and analyzed them. The laboratory tests indicated that Asian Seabass were infected by RSIV. More than 30 marine and brackish water fish species such as Sea bass, Grouper fish and Red sea bream etc., are known to be susceptible to this virus. This virus can causes mortality up to 100% depending on host fish species, size, age, water temperature and other culture conditions. The main target organs for RSIV are spleen, kidney, heart, intestine and gill.
He said that since RSIV is a new emerging virus in Indian waters, proper management measures have to be undertaken to mitigate its spread. Further studies are being carried out in the college and the process of preparing preventive measures for mitigation of the virus is in progress. He cautioned that proper scientific management practices should be adopted to control and prevent the spread of RSIV such as -Stocking pathogen-free fish; implementing hygiene practices on farms and avoiding practices that can decrease water quality such as overcrowding and overfeeding.
The college has been carrying out disease surveillance programme under the “National Surveillance of Aquatic Animal Disease” project in both fresh water and brackish water cultured fishes. The programme was initiated by National Bureau of Fish Genetic Resources (NBFGR), Lucknow. The prime objective of the project is to create awareness about emerging aquatic animal diseases and preventive measures among the fish farmers in the regions where fish culture and shrimp farming are being carried out in the State of Karnataka through passive and active surveillance.
The team of pathologists that analyzed the samples included Dr. Girisha S K, Puneeth T G, Nithin M S, Dr. Naveen Kumar B T, Dr. Ajay Dr S K Vinay T N, Dr. Suresh T, Dr. Venugopal M N and Dr. Ramesh K S from the Department of AAHM. Fish farmers can contact have been 0842-2246384 if the symptoms of RSIV are observed.