Effects of water acidification on immune responses of the gercacinid, Cardiosoma armatum (Herklots, 1851)

Abstract

The biological response to chemical pollutants reflects the acid–base status of an aquatic ecosystem. The gercacinid, Cardiosoma armatum (75±0.1 g) was exposed to acidified waters to evaluate the effects on its immune parameters. The crabs were exposed to pH 4.0, 5.0, 6.0 and 7.8 (control) for 28 days. The hematological parameters of control crabs and crabs exposed to varied doses of acidified water indicated a marked reduction. Significant (p<0.05) higher alkaline phosphatase and albumen were obtained in pH 4.0, 5.0 and 6.0 compared to control; other values were mostly similar to control. The highest superoxide dismutase (SOD) (252.61±0.06 min/mg pro) was recorded in control group, while highest CAT activity (2.08±0.16 min/mg protein) was recorded in crabs exposed to pH 4 treatment. Furthermore, the control group's SOD activity was significantly higher than the exposed groups. With a lower pH, the quantities of malondialdehyde increased substantially and were significantly different from the control group. While these findings demonstrate that changes in pH have limited impact on energy use, decreasing immune system conditions show that C. armatum is susceptible to pH variations and may be influenced in aquaculture, where a pH drop is more prominent.