Photobacterium damselae subsp. damselae, an Emerging Pathogen Affecting New Cultured Marine Fish Species in Southern Spain

Aquaculture is the fastest growing food-producing sector, accounting almost 50% of the world food fish demand. Considering the projected population growth over the next two decades, it is estimated that at least an additional 40 million tonnes of aquatic food will be required by 2030 to maintain the current per capita consumption (NACA/FAO, 2001). Marine aquaculture production was 30.2 million tonnes in 2004, representing 50.9% of the global aquaculture production (FAO, 2004). By major groupings, fish is the top group whether by quantity or by value at 47.4% and 53.9%, respectively. However, according to the World Aquaculture Society (WAS, 2006), the future of this sector must be based on the increase of scientific and technical developments, on sustainable practices, and, mainly, on the diversification of the cultured fish species. For this reason, the European Union has designed an innovative plan to increase the culture of new fish and shellfish species, mainly marine, maintaining the production of other consolidated species (UE, 2010). Marine fish farming is a very important activity of Spanish aquaculture industry. The main marine fish species intensively cultured are gilt-head seabream (Sparus aurata), European seabass (Dicentrarchus labrax), and turbot (Scophthalmus maximus), achieving production percentages of 47.91, 12.5 and 18.62%, respectively (MAPA, 2008). In last 7 years, several new marine fish species are being evaluated as potential candidates for aquaculture production. In Southern Spain, studies on the reproductive cycles, nutrition, growth, histology and immune system of species such as Senegelese sole (Solea senegalensis), redbanded seabream (Pagrus auriga), common seabream (Pagrus pagrus), white seabream (Diplodus sargus), and meagre (Argyrosomus regius) are ongoing (Cardenas & Calvo, 2003; Prieto et al., 2003; Ponce et al., 2004; Manchado et al., 2005; Fernandez-Trujillo et al., 2006; 2008; Martin-Antonio et al., 2007; Cardenas & Manchado, 2008). However, the intensive