A case study of gas bubble disease in Black Sea Bream (Spondylosoma cantharus)

Abstract

        Gas bubble disease (GBD) is a complex pathophysiological change common to a wide range of freshwater, migratory and marine fish species. The basic mechanism of pathogenesis is based upon embolic effect of "wondering" gas bubbles through the vascular system and their ability to damage practically any tissues that absorb them.
         However in most cases, the first changes develop in gill epithelium, resulting in hyperplasia and epithelial desquamation and necrosis at the final stage. Changes reversible at certain stages are the triggers for hypoxic and anoxic conditions of the organism and in most cases, the causa mortis.
         Except for the easily visible gas bubbles in the dermis, feature of the GBD are behavioural changes induced by the absorption and embolic trauma of gas bubbles in the brain tissue. Other gross pathomorphological lesions are mainly restricted to the lesions induced by low feeding capability of affected fish.
         This study deals with causes and triggers of the GBD, its pathogenesis, patho-physiological and gross pathomorphological changes in the black sea bream (Spondylosoma cantharus) caught in wild and held in concrete tank.
         The morbidity reached 50 % during two months, with mortality of 37.5 % of affected fish.