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Not AvailableThe disease, viral nervous necrosis caused by betanodaviruses is an emerging threat to the fish farming industry. The virus has a broad range of fish hosts and infects all age groups of fishes causing huge economic loss to the entrepreneurs. Acute and latent infections were described for this virus which may also remain dormant/persistent in carrier fishes/invertebrates. Estimation of the prevalence of the virus was attempted in this study using advanced molecular tools. A nested rt-PCR method followed by nucleotide sequencing and subsequent bioinformatics analysis was adopted. Samples were collected from hatchery, marine, coastal & low-saline farms and wild environments from eight sites along the east and west coasts of India. Samples included apparently healthy fishes along with moribund with clinical signs. Nodavirus infection was diagnosed in 19.7% of samples analysed. Prevalence ranged from 40.6% in marine farms, 29.5% in coastal farms, 23.6% in wild marine and 5.6% in wild coastal environments with no infection in the marine hatchery and low-saline farm samples. All the isolates belonged to RGNNV genotype which has the widest host range among all the species of Betanodavirus. This study also identified new susceptible fish species to betanodavirus infection naturally.Not Availabl

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Not AvailableParasites of the genus Perkinsus predominantly infect bivalves, and two species among them, P. olseni and P. marinus, are notifiable to OIE. P. olseni infections are known to cause extensive damage to wild as well as farmed bivalves globally with enormous implications to its fishery. Consequent to the initiation of a surveillance programme for aquatic animal diseases in India, Perkinsus infections were observed in many species of bivalves. The present paper describes P. olseni infections in the short neck yellow clam, Paphia malabarica from the southwest coast of India. Diagnosis of the parasite was carried out using Ray's Fluid Thioglycollate Medium culture, histology, in-situ hybridisation and molecular taxonomy. Pathology of infection and development of zoospores is also described. This forms the first report of a P. olseni infection in P. malabarica. High prevalence and intensity of infection of Perkinsus in clams raises concerns, as clam reserves in this geographical area sustain fisheries and the livelihoods of local fishing communitiesNot Availabl