The Effects of Stressful Conditions on an Artificial Aeromonas hydrophilia Challenge in Hybrid Catfish (Clarias gariepinus X Clarias batrachus)

摘要

Catfish (Clarias sp.), cultured extensively and intensively throughout Southeast Asia, are generally regarded as robust animals, which do not readily succumb to stress-associated mortalities. However, they frequently encounter common environmental stimuli on the Thai fish farms, which, are known to result in a stress response in aquatic animals. This in turn can compromise their immune defences against disease. The laboratory-based study discussed here examined the effect of various environmental stressors on the disease status of the animal when artificially bath challenged with Aeromonas hydrophila. The highest percentage of total mortalities was found in the group receiving high temperature stress alone compared with the other stress-only groups.The highest percentage mortality was experienced in the fish p'oup receiving low water temperature and a bacterial bath challenge. Control fish also died, but these deaths were thought to be due to wounds inflicted during fighting with fish held in thesame tank.