Effects of Loma morhua ( Microsporidia) infection on the cardiorespiratory performance of Atlantic cod Gadus morhua (L).

• Published in: Journal of Fish Diseases
• Main Authors: Powell, M D, Gamperl, A K
• Other Authors: Norges Forskningsråd
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2015
• Subjects: Loma; atlantic cod; Gadus morhua
• Online Access: http://dx.doi.org/10.1111/jfd.12352; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fjfd.12352; https://onlinelibrary.wiley.com/doi/pdf/10.1111/jfd.12352; https://onlinelibrary.wiley.com/doi/full-xml/10.1111/jfd.12352

Abstract The microsporidian L oma morhua infects Atlantic cod ( G adus morhua ) in the wild and in culture and results in the formation of xenomas within the gill filaments, heart and spleen. Given the importance of the two former organs to metabolic capacity and thermal tolerance, the cardiorespiratory performance of cod with a naturally acquired infection of Loma was measured during an acute temperature increase (2 °C h −1 ) from 10 °C to the fish's critical thermal maximum ( CT Max ). In addition, oxygen consumption and swimming performance were measured during two successive critical swimming speed ( U crit ) tests at 10 °C. While Loma infection had a negative impact on cod cardiac function at warm temperatures, and on metabolic capacity in both the CT Max and U crit tests (i.e. a reduction of 30–40%), it appears that the Atlantic cod can largely compensate for these Loma ‐induced cardiorespiratory limitations. For example, (i) CT Max (21.0 ± 0.3 °C) and U crit (~1.75 BL s −1 ) were very comparable to those reported in previous studies using uninfected fish from the same founder population; and (ii) our data suggest that tissue oxygen extraction, and potentially the capacity for anaerobic metabolism, is enhanced in fish infected with this microsporidian.