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Respiratory pathogenesis of amoebic gill disease (AGD) in experimentally infected Atlantic salmon Salmo salar


Leef, MJ and Harris, JO and Powell, MD, Respiratory pathogenesis of amoebic gill disease (AGD) in experimentally infected Atlantic salmon Salmo salar, Diseases of Aquatic Organisms, 66, (3) pp. 205-213. ISSN 0177-5103 (2005) [Refereed Article]

DOI: doi:10.3354/dao066205


The aim of this study was to investigate the respiratory responses of Atlantic salmon, Salmo salar, experimentally affected with amoebic gill disease (AGD). In Series I, arterial blood samples were taken over a 96 h period following amoebae addition to examine potential respiratory effects associated with initial exposure. No major significant treatment effects were found between fish exposed to amoebae and control (non-exposed) fish. Arterial pH (pH a) was seen to be significantly elevated at 48 h in AGD fish relative to the 0 h time point. To investigate the long-term respiratory effects associated with infection, fish were similarly exposed to amoebae and sampled over a 16 d period. As for Series I, caudal blood pH was significantly elevated by Day 2 (48 h) compared to the pre (Day 0)-time point, suggesting that initial exposure to amoebae and/or amoebae attachment may have induced an initial respiratory alkalosis via increased ventilation frequency and/or amplitude. From Day 7 onwards, and coinciding with a significant increase in the percentage of affected gill filaments, blood pH decreased significantly, possibly indicating the onset of the characteristic respiratory acidosis that has previously been described for experimentally AGD-affected Atlantic salmon. Although fish in this study showed up to 90 % AGD-affected filaments, the corresponding respiratory results do not reflect a major acid-base disturbance. Therefore, the findings from the present study support the contention that, although AGD only affects the gill, AGD-associated mortality in Atlantic salmon may not be primarily associated with respiratory failure. © Inter-Research 2005.

Item Details

Item Type:Refereed Article
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Fisheries sciences
Research Field:Aquaculture
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - aquaculture
Objective Field:Fisheries - aquaculture not elsewhere classified
UTAS Author:Leef, MJ (Dr Melanie Leef)
UTAS Author:Harris, JO (Associate Professor James Harris)
UTAS Author:Powell, MD (Dr Mark Powell)
ID Code:38290
Year Published:2005
Web of Science® Times Cited:16
Deposited By:TAFI - Aquaculture
Deposited On:2005-08-01
Last Modified:2006-04-03

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