Inter-Research > DAO > v88 > n1 > p69-84  
Diseases of Aquatic Organisms

via Mailchimp

DAO 88:69-84 (2009)  -  DOI:

Pseudoloma neurophilia infections in zebrafish Danio rerio: effects of stress on survival, growth, and reproduction

Jennifer M. Ramsay1,2, Virginia Watral2, Carl B. Schreck1,3, Michael L. Kent2,4,*

1Department of Fisheries and Wildlife, 2Department of Microbiology, 3Oregon Cooperative Fish and Wildlife Research Unit, US Geological Survey, and 4Department of Biomedical Sciences, Oregon State University, Corvallis, Oregon 97331, USA
*Corresponding author. Email:

ABSTRACT: Pseudoloma neurophilia (Microsporidia) is a common disease of zebrafish Danio rerio, including those used as research models. We conducted a study comprised of 4 separate experiments to determine the effects of husbandry stress on preexisting and experimental P. neurophilia infections and the subsequent effects on survival, infection onset and intensity, fish growth, and reproduction. In fish (AB strain) with preexisting infections, stress or feeding cortisol significantly increased mortality over 7 wk compared to no stress or cortisol treatment. In contrast, no mortality was observed in fish (TL strain) experimentally exposed to P. neurophilia over 10 wk. A third experiment involved experimental exposure of AB fish to P. neurophilia and exposure to crowding and handling stressors. No mortality was associated with P. neurophilia regardless of stress treatment over a period of 20 wk. However, the onset of infection occurred sooner in stress-treated fish. Stress significantly increased the mean intensity of infection (described as xenoma area/spinal cord area in histological sections) at Week 20 post-exposure (PE). In fish with preexisting infections, myositis was significantly greater in stressed and cortisol-treated fish than those not stressed. With experimental exposure of AB fish, stressed and infected groups weighed significantly less than the control group at Week 20 PE. Regarding fecundity, the number of larvae hatched at 5 d post fertilization was negatively associated with mean infection intensity among P. neurophilia-infected and stressed AB fish. These experiments are the first to show empirically that P. neurophilia can be associated with reduced weight and fecundity, and that stress can exacerbate the severity of the infection.

KEY WORDS: Pseudoloma neurophilia · Stress · Growth · Reproduction · Mortality · Microsporidia

Full text in pdf format 
Cite this article as: Ramsay JM, Watral V, Schreck CB, Kent ML (2009) Pseudoloma neurophilia infections in zebrafish Danio rerio: effects of stress on survival, growth, and reproduction. Dis Aquat Org 88:69-84.

Export citation
Mail this link - Contents Mailing Lists - RSS
Facebook - - linkedIn