Oxygen consumption rate in Gasterosteus aculeatus-Schistocephalus solidus system from a non-migratory naturally infected population

Abstract The three spine stickleback Gasterosteus aculeatus is a specific obligatory intermediate host for the cestode worm Schistocephalus solidus . This system is commonly used to investigate the host-parasite interaction in fishes. Despite the interesting attempts which have been made to quantify the impact of the parasite over the respiration rate of the host fish, none of the previous reports took in consideration that stickleback is diversified in different ecotypes according to its ability to made reproductive migration, from and to the sea. Here the oxygen consumption rate in specimens of three-spine stickleback collected from a non-migratory population was quantified with the aim to test if the S. solidus infection drives a change in the oxygen consumption level of the host fish. The results showed that the infected fishes have a higher rate of oxygen consumption compared with the uninfected one. The differences were due to a direct effect of the parasite, not merely to its contribution to the whole oxygen consumption rate. The data were compared with previous reports, showing that the non-migratory population was characterized by a different level of oxygen consumption rate. The differences were interpreted in terms of divergence in physiological adaptations which had to be appeared in different populations.