Dynamics of Reinfection by <i>Neobenedenia</i> sp. (Monogenea, Capsalidae) in Almaco Jack, <i>Seriola rivoliana</i>, Kept in a Cultivation System

Fish susceptibility to parasitic infection is a crucial issue in aquaculture, where the density of captive fish increases the intensity of parasitic infections. Monogeneans are a group of parasitic flatworms that include pathogenic species for fish, among them Neobenedenia spp., which pose significant challenges for fish health in farming systems. Understanding the dynamics of parasitism in fish and how they may vary according to host susceptibility or environmental conditions is essential for the development of effective management strategies in aquaculture. Therefore, the aim of this study was to investigate the individual susceptibility of Almaco jack (Seriola rivoliana) to infections by Neobenedenia sp. and examine how reinfection affects parasite load in an aquaculture setting. Our findings unveiled an aggregated distribution of parasites in the fish population, indicating a non-random pattern influenced by specific host factors. Furthermore, our results revealed that even minor temperature variations, such as an increase of just 1°C, were associated with a noticeable rise in parasite abundance. These results underscore the importance of regular monitoring in S. rivoliana tank-maintained systems, as even minor temperature fluctuations can cause a substantial increase in Neobenedenia sp. infections, particularly in more susceptible individuals.