Lumpfish (Cyclopterus lumpus, Linnaeus) is susceptible to viral nervous necrosis: Result of an experimental infection with different genotypes of Betanodavirus

Anna Toffan*, Maria De Salvador, Felix Scholz, Tobia Pretto, Alessandra Buratin, Hamish D Rodger, Marica Toson, Argelia Cuenca, Niccolò Vendramin

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

In recent years, the use of cleaner fish for biological control of sea lice has increased considerably. Along with this, a number of infectious diseases have emerged. The aim of this study was to investigate the susceptibility of lumpfish (Cyclopterus lumpus) to Betanodavirus since it was detected in asymptomatic wild wrasses in Norway and Sweden. Three betanodaviruses were used to challenge lumpfish: one RGNNV genotype and two BFNNV genotypes. Fish were injected and monitored for 4 weeks. Brain samples from clinically affected specimens, from weekly randomly selected fish and survivors were subjected to molecular testing, viral isolation, histopathology and immunohistochemistry. Reduced survival was observed but was attributed to tail-biting behaviour, since no nervous signs were observed throughout the study. Betanodavirus RNA was detected in all samples, additionally suggesting an active replication of the virus in the brain. Viral isolation confirmed molecular biology results and revealed a high viral titre in BFNNV-infected groups associated with typical lesions in brains and eyes of survivor fish. We concluded that lumpfish are susceptible to Betanodavirus, as proven by the high viral titre and brain lesions detected, but further studies are necessary to understand if Betanodavirus can cause clinical disease in this species.
Original languageEnglish
JournalJournal of Fish Diseases
Volume42
Issue number12
Pages (from-to)1667-1676
Number of pages10
ISSN0140-7775
DOIs
Publication statusPublished - 2019

Keywords

  • Betanodavirus
  • Cleaner fish
  • Lumpfish
  • Nervous necrosis virus
  • Viral encephalopathy and retinopathy

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