Oxidative stress biomarkers in the African sharptooth catfish, Clarias gariepinus, associated with infections by adult digeneans and water quality

José Chissiua Dumbo; Beric Michael Gilbert; Annemariè Avenant-Oldewage

doi:10.1016/j.ijppaw.2020.07.002

Oxidative stress biomarkers in the African sharptooth catfish, Clarias gariepinus, associated with infections by adult digeneans and water quality

Int J Parasitol Parasites Wildl. 2020 Jul 13:12:232-241. doi: 10.1016/j.ijppaw.2020.07.002. eCollection 2020 Aug.

Authors

José Chissiua Dumbo^{1

2}, Beric Michael Gilbert^{1

3}, Annemariè Avenant-Oldewage¹

Affiliations

¹ Department of Zoology, University of Johannesburg, P.O. Box 524 Auckland Park, Johannesburg, 2006, South Africa.
² Department of Biological Sciences, Eduardo Mondlane University, P.O. Box 257, Maputo, Mozambique.
³ Spectrum Analytical Facility, University of Johannesburg, P.O. Box 524 Auckland Park, Johannesburg, 2006, South Africa.

Abstract

Parasites and environmental features could synergistically act as stressors to the health of their hosts. The objectives of this study were to evaluate the effect of: (i) water quality, host sex, size and body condition on adult digenean parasite infections; (ii) digenean infections and host sex and size on the oxidative stress biomarkers and body condition of hosts; and (iii) water quality on the oxidative stress biomarkers and body condition in Clarias gariepinus. Water quality variables were measured and C. gariepinus were collected each month for a year for examination of two intestinal digeneans, Masenia nkomatiensis and Glossidium pedatum, and determination of body condition and measurement of biomarkers in the host. The results indicated that the intensity of M. nkomatiensis was positively correlated with electrical conductivity and total dissolved solids. Prevalence of G. pedatum was negatively correlated with electrical conductivity, salinity and total dissolved solids. High summer water temperature was strongly associated with high digenean infections. There was no host body condition, sex or size bias for any of the parasite infection variables. Differences in the biomarker levels and body condition between uninfected fish and those infected with M. nkomatiensis or G. pedatum were insignificant indicating a low effect of the digenean parasites on oxidative stress biomarkers and body condition in the fish. However, total protein levels were positively associated with host size, and lipid peroxidation was negatively related to host body condition; total protein levels were also positively correlated with temperature and negatively correlated with dissolved oxygen. Host body condition was only negatively correlated with dissolved oxygen. Overall the trends observed in the data showed that the parasites have a negligible effect on oxidative stress in host fish and the trends observed for all variables (water quality, stress biomarkers, body condition and parasite infections) showed a strong seasonal pattern.

Keywords: Body condition; Digenean; Fish; Fish parasite; Oxidative stress biomarkers; Water quality.