It is a completely rare case, especially among the wild fish species. The observed swim bladder extruding from the body can be probably occurred following a historical impairment in early developmental period. I do not think that infectious agents predispose this abnormality. Contaminants (organic and inorganic) have been associated with many kind of deformation in fish body. I, however, suppose that one or some undesired environmental factors led to engender of that. For etiology of this abnormality, more clinical investigations should be done. Beside the morphological observation, I think the anatomical investigation must be applied to elucidate any changes in connection of swim bladder to body (i.e. this species is a physioclistous teleost with two chambers). The histological technique should be included to determine swim bladder wall changes (if any).