Metazoan Parasites of the European Sea Bass Dicentrarchus labrax (Linnaeus 1758) (Pisces: Teleostei) from Corsica

Abstract

As in many parts of the world, aquaculture production in the Mediterranean has been expanding rapidly over recent years (Basurco & Lovatelli, 2005). The continuous decline of ocean fisheries stocks has provided impetus for rapid growth in aquaculture. Global production of farm fish has more than doubled in the past 20 years with the growing demands of an expanding population, and it seems that grow is set to continue. It has been the fastest growing food production sector since 1970, with an increase at a compounded rate about 9.2% per year (Guo & Woo, 2009; Naylor et al., 2000). Alongside, and perhaps partly due to this rapid expansion, the welfare of farmed fish has received increasing attention. Fish welfare is an important issue for the industry, not just for public perception, marketing and product acceptance, but also often in terms of production efficiency, quality and quantity (Ashley, 2006). Many factors influenced the rapid increase in the production of cultured fish species in the last two decades (FAO, 2010). One of the most important factors is the great development and diffusion of sea-cage culture. The success of the sea-cage farming is essentially correlated with the possibility to reduce production cost. On the other hand, aquaculture of fish is not without problems. Cages constitute an open system, which allow free exchange between wild and caged organisms, leading to the emergence of characteristic diseases (Ghittino et al., 2003; Merella et al., 2006). The maintenance of a good health is a major problem in animal populations. Rapid development of fish culture in marine cages has been associated with an emergence of parasitic diseases (Fioravanti et al., 2006; Nowak, 2007). The difficulty of managing disease within sea-cages is regarded as a major drawback (Mladineo, 2006). Fish parasites are a major component of aquatic biodiversity, and their monitoring is considered an essential element of the management of the health for animals. Parasites that have low rates of infestation and minor pathological effects on their hosts under natural conditions can easily spread in populations confined to rearing systems, causing serious outbreaks and epizootics diseases resulting in significant economical losses (Combes, 1990; Ghittino et al., 2003; Johnson et al., 2004; Naylor et al., 2000). The environmental conditions in culture systems, in particular increased density of fish, repeated introduction of hosts, homogeneous host populations, fast growth and a potential decrease in genetic diversity have an important effect on commercial production