Effects of temperature on amoebic gill disease development: Does it play a role?

TitleEffects of temperature on amoebic gill disease development: Does it play a role?
Publication TypeJournal Article
Year of Publication2019
AuthorsBenedicenti, O, Pottinger, TG, Collins, C, Secombes, CJ
JournalJournal of Fish Diseases
Pagination1241 - 1258
Date Published09/2019
ISBN Number0140-7775
Keywordsamoebic gill disease, Paramoeba perurans, Temperature

A relationship between increasing water temperature and amoebic gill disease (AGD) prevalence in Atlantic salmon (Salmo salar) has been noted at fish farms in numerous countries. In Scotland (UK), temperatures above 12°C are considered to be an important risk factor for AGD outbreaks. Thus, the purpose of this study was to test for the presence of an association between temperature and variation in the severity of AGD in Atlantic salmon at 10 and 15°C. The results showed an association between temperature and variation in AGD severity in salmon from analysis of histopathology and Paramoeba perurans load, reflecting an earlier and stronger infection post‐amoebae exposure at the higher temperature. While no significant difference between the two temperature treatment groups was found in plasma cortisol levels, both glucose and lactate levels increased when gill pathology was evident at both temperatures. Expression analysis of immune‐ and stress‐related genes showed more modulation in gills than in head kidney, revealing an organ‐specific response and an interplay between temperature and infection. In conclusion, temperature may not only affect the host response, but perhaps also favour higher attachment/growth capacity of the amoebae as seen with the earlier and stronger P. perurans infection at 15°C.

Short TitleJournal of Fish Diseases