In the "Laboratório de Piscicultura Estuarina e Marinha da Universidade Federal do Rio Grande" the rearing of Trachinotus marginatus (pompano) is studied, and in one of these rearing a yersioniosis outbreak occured. The disease was manifested by swimming disturbances, exophthalmiawith panophthalmitis and the classic red mouth, (red mouth disease (RMD). The necropsies revealed focus of peritoneal hemorrhage, esplenomegalyand hepatomegaly.Microscopically a panophthalmitis with dense inflammatory infiltrates was observed, which affected almost all ocular structures. These infiltrates were constituted by granulocytes, lymphocytes, macrophages and eosinophylicgranular cells (ECG), in the exudatessmall structures less colored with Gram negative bacteria aspect were observed. The immunohistochemical, which used a monoclonal antibody anti- Yersinia ruckeri waspositive. The RMD is caused by enterobacteriaGram negative, which affects both freshwater and saltwater fish, with predominance in salmonids. This is the first known yersiniosis outbreak in Trachinotus marginatus in Brazil and it is necessary to keep this disease in mind at the moment of rearing fish of this species.
fish; Trachinotus marginatus; yersiniosis; inmunohistochemical
