Authors

N Masud²; A Ellison¹; J Cable¹;  ¹ Cardiff School of Biosciences, Cardiff University, UK;  ² Cardiff University, UK

Discussion

The transport of fish in aquaculture and the ornamental trade exposes fish to multiple stressors that can cause mass mortalities and economic loss. Previous research on fish transport has largely focused on chemical stress related to deterioration in water quality. For many small ornamental fish, however, water quality remains stable during routine transport leaving mechanical stress as a neglected stressor when studying fish welfare. Elevated stress induces immunosuppression, which increases the chance of contracting infections and reducing the rate of recovery. Here, using two experimental infection protocols, we investigate how parasite infections prior to and after simulated transport impacts infection trajectories of the ectoparasitic Gyrodactylus turnbulli. Guppies (Poecilia reticulata) that were exposed to infection before simulated transport suffered significantly higher parasite burden compared to fish that were not transported. In constrast, fish exposed to parasites after transport did not suffer a significant increase in parasites. This increased disease susceptibility due to fish infections prior to transport demonstrates the potential to mitigate the impact of parasites on stock survival and we suggest improvements for reducing parasite burden on stock survival.