Molecular detection of betanodavirus in orange-spotted grouper ( Epinephelus coioides ) broodstock maintained in recirculating aquaculture systems and sea cages

摘要: Wild collected orange-spotted grouper were domesticated in Recirculating Aquaculture Systems (RAS) and sea cages for fish breeding. While breeding, viral nervous necrosis (VNN) infection was observed both the systems after 18 months of domestication. Out 50 broodfish used study, 11 (22%) fishes found positive VNN examined by reverse transcriptase polymerase chain reaction (RT-PCR) method. Quantitative real-time PCR (qPCR) study also confirmed presence suspected fish, detectable amount virus copy number brain, optic nerve, caudal fin, muscle, gills. Analysis isolated gene sequence from closely related to red-spotted (RGNNV) genotype suggests that isolates are probably endemic Indian coast. The indicated sub-adults infected wild remained as carrier during domestication subsequently disease outbreak has occurred when water temperature increased culture environment. This is first report on broodstock India. results illustrated large population marine sub-clinically with betanodavirus therefore, early detection should be adopted best management practices breeding sustainable aquaculture development species.