Respiration of Eudiaptomus gracilis infected with Diphyllobothrium latum

Abstract

The influence of infection of Diphyllobothrium latum larvae on the respiratory metabolism of host Eudiaptomus gracilis was investigated. The oxygen consumption of infected and noninfected specimens of E. gracilis was determined at 20 °C in cartesian diver respirometers as modified by Zeuthen. The infected copepods were investigated on days 1, 3, 7, 10, and 13 of development of parasite larvae in the body cavity. All copepods used in the experiments were cultivated under the same conditions. The mean oxygen consumption by infected copepods on all the days of investigation was lower than that of noninfected specimens. In consideration of the wide variation of individual measurements, the difference in early respiratory rates between infected and noninfected copepods is not convincing. In the period 6–10 days after infection, a clearer statistically significant drop in oxygen consumption by copepods occurred. This period coincides with organogenesis of larvae likely connected with increasing demands for building materials and secretion of metabolites. These processes can disturb the physiological equilibrium of the host.