The finfish species reared in marine intensive conditions in the French Caribbean Islands are imported (European seabass, American red drum and Oreochromis hybrids) or local (Carangids and Lutjanids) species. The European seabass (Dicentrarchus labrax ) is susceptible, during its first year of life, to a contagious disease characterized by whirling and hyperexcitability, associated with severe lesions of the brain, viral particles being pointed out in the damaged nervous cells.