Effect of the endosymbiotic pea crab Calyptraeotheres garthi on the metabolic rate and oxidative status of the slipper limpet Crepidula cachimilla

Abstract

Parasites may induce metabolic changes and imbalances in the redox status of hosts. This study tested the effect of parasites on the O2 consumption rate (O2-CR) of hosts, and explored the link between O2-CR and oxidative stress in parasitized hosts. We used the symbiotic pea crab Calyptraeotheres garthi and its slipper limpet host Crepidula cachimilla as models. The O2-CR of long-term (3 months) infested limpets was 2.5 times greater than that of long-term uninfested limpets. Also, the O2-CR of limpets stripped of crabs 24 h before measurements was intermediate between that of long-term infested and uninfested limpets. These results indicate a parasitic relationship between C. garthi and Cr. cachimilla, and suggest that the effect of the parasite on the metabolic rate of limpets is reversible. Lastly, the activity of two antioxidant enzymes (CAT and GST) as well as lipid peroxidation did not vary between infested and uninfested limpets. Thus, increased O2-CR is not necessarily coupled with oxidative stress in pea crab-parasitized slipper limpets.