Reduced superoxide dismutase activity in Palaemonetes argentinus (Decapoda, Palemonidae) infected by Probopyrus ringueleti (Isopoda, Bopyridae)

Cellular oxidative stress may promote damage or death in biological systems and may be caused by production of pro-oxidant molecules known as reactive oxygen species (ROS). The aim of this work was to analyze the activity of antioxidant enzymes (catalase [CAT], superoxide dismutase [SOD] and glutathione peroxidase [IGPx]) in the shrimp Palaemonetes argentinus Nobili, 1901 infected by Probopyrus ringueleti (Verdi & Schuldt, 1987), a gill chamber parasite known for its capacity to cause host metabolic changes, including changes in oxygen consumption rates. Infested and non-infested shrimp were collected in the Patos Lagoon estuary (southern Brasil), where the prevalence of the parasite may be as high as 70%. No significant differences were observed for either CAT or GPx activities. However, SOD activity was significantly reduced in infected shrimp, suggesting that bopyrid isopod respiratory impairment resulted in reduced SOD enzyme activity.