Necrotizing myositis associated with parasitism by Myxobolus sp. (Myxozoa) in the palate of the violet goby, Gobioides broussonnetii (Gobiidae), from Marajó Island, Brazil

The Amazon estuary is a unique environment, in which a wide variety of both marine and freshwater fish species can be found, providing an important source of income for local populations. Forty G. broussonnetii specimens were collected from an area adjacent to the city of Salvaterra on Marajó Island, in the Brazilian state of Pará, in 2011. The necroscopic analysis of the hosts revealed the presence of milky rounded cysts throughout the palate. Microscopic analysis of the parasitized fragments revealed that the squamous epithelium covering the palate was intact, although Myxobolus sp. cysts were observed in the cytoplasm of the striated skeletal muscles of the palate, as found in other myxosporids. Overall, the macro- and microscopic findings of the present study confirm the presence of necrotizing myositis in the palate of G. broussonnetii associated with parasitism by Myxobolus sp. ⺠The necropsy revealed the presence of milky rounded cysts throughout the palate. ⺠The necrosis was widespread in the parasitized muscles by Myxobolus sp. ⺠The area of the necrosis was infiltrated by monocytes, neutrophils, and lymphocytes.