Infection of European eel by Anguillid herpesvirus 1: from basic research to conservation programs

• Main Author: Delrez, Natacha
• Other Authors: Vanderplasschen, Alain
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: ULiège - Université de Liège 2021
• Subjects: European eel; Anguillid herpesvirus 1; conservation; Pathogenesis; bioluminescence imaging; Life sciences; Veterinary medicine & animal health; Sciences du vivant; Médecine vétérinaire & santé animale; Anguilla anguilla
• Online Access: https://orbi.uliege.be/handle/2268/266404

The European eel (Anguilla Anguilla) is a culturally and commercially important fish species and along with other members of the genus Anguilla, they are flagship species for aquatic conservation efforts. Anguillid eels have a fascinating and complex life cycle involving different life stages and extended migration through both marine and freshwater environments. The lifecycle of the European eel begins in the Atlantic Ocean. After hatching, leptocephali larvae drift thousands of kilometres across the ocean to reach continental coastal waters where they metamorphose into glass eels. These juvenile eels then migrate upstream towards freshwater habitats where they grow into yellow eels and remain there for several years. Finally, they fully mature into silver eels and migrate back to their place of birth, where they reproduce before dying. Within the last 50 years, the European eel population has dramatically decline and the species is now critically endangered. The reason for this steep decline in population is likely to be multifactorial, with one potential major factor being infectious diseases. In terms of viral diseases, Anguillid herpesvirus 1 (AngHV 1) is the causative agent of a haemorrhagic disease affecting freshwater eels (Anguilla spp.), and is one of the most frequently detected viruses from European eels, especially in fish farms. This herpesvirus is a member of the genus cyprinivirus of the family Alloherpesviridae. As a consequence of this decline, the European Commission has established the “Eel Recovery Plan” within member states with the aim of protecting and restoring the population of European eel. One of the main measures of this plan relies on restocking. This process involves the active transfer of eels to inland areas where eel populations have declined. Although this restocking is widely practiced in Europe, additional studies are still needed to evaluate and improve its effectiveness. The broad objective of the present thesis was to contribute to the conservation of the critically ...