Abstract
There have been recent efforts amongst immunologists to develop approaches for following individual fish during challenges with viral and bacterial pathogens. This study contributes to assessing the feasibility of using such approaches to study amoebic gill disease (AGD). Neoparamoeba perurans, agent of AGD, has been responsible for widespread economic and fish loss in salmonid aquaculture. With the emergence of AGD in Europe, research into infection dynamics and host response has increased. This study investigated the effect of repeat exposure to anaesthesia, a necessary requirement when following disease progression in individual fish, on N. perurans. In vitro cultures of N. perurans were exposed every 4 days over a 28‐day period to AQUI‐S® (isoeugenol), a popular anaesthetic choice for AGD challenges, at a concentration and duration required to sedate post‐smolt salmonids. Population growth was measured by sequential counts of amoeba over the period, while viability of non‐attached amoeba in the culture was assessed with a vital stain. AQUI‐S® was found to be a suitable choice for in vivo ectoparasitic challenges with N. perurans during which repetitive anaesthesia is required for analysis of disease progression.
Highlights
With the continued expansion of the global aquaculture industry (FAO, 2016), and related research on fish, there is a need for refinement in experimental approaches, including analyses of in vivo immune responses
The first occasion of amoebic gill disease (AGD) as an epizootic was observed in an Atlantic salmon, Salmo salar, and rainbow trout, Oncorhynchus mykiss, sea farm located in east Tasmania, during the summer of 1984–85 (Munday, 1986)
AQUI-Sâ was selected due to the popularity of use in countries most severely affected with AGD, alongside recent findings of no short-term impacts upon attachment or viability of N. perurans after single exposure (Shijie et al, 2016)
Summary
With the continued expansion of the global aquaculture industry (FAO, 2016), and related research on fish, there is a need for refinement in experimental approaches, including analyses of in vivo immune responses. Northern Europe has suffered increasing AGD prevalence with substantial economic and fish stock losses It was first described in eight farms in Ireland, in 1995 (Palmer, Carson, Ruttledge, Drinan, & Wagner, 1997; Rodger & McArdle, 1996), in Scotland, United Kingdom in 2006 (Young, Dykova, Snekvik, Nowak, & Morrison, 2008), with typical losses ranging from 10% to 20% but occasionally reaching 70% (Marine Scotland 2012). AQUI-Sâ was selected due to the popularity of use in countries most severely affected with AGD, alongside recent findings of no short-term impacts upon attachment or viability of N. perurans after single exposure (Shijie et al, 2016) This is the first paper to report upon the repeated exposure of N. perurans to fish anaesthetics and to describe any adverse effects found on this aquaculture ectoparasite
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
