Características anatomopatológicas de cromatoforomas em dois peixes betta(Betta splendens).

Abstract

Cutaneous chromatophoroma or pigment cell tumors are common in fish and their occurrence has been reported in marine and freshwater species. The betta fish (Betta splendens) is an Anabantid fish and popular throughout the world due to its vibrant colors and phenotypic variations, many of which come from artificial selection in captivity. The objective of this work is to report the cases of 2 betta fish with died. During the necropsy, it was observed that all the animals presented skin masses in some parts of the body, with an irregular, friable and blackish to white color. When performing the cross-sections, it was macroscopically verified that the masses were not located only in the cutaneous region, but also penetrated into skeletal muscle tissue, spinal cord and some organs of the coelomic cavity. Microscopically, it was found in the first case that the masses were composed of cells with abundant olive-green pigment in their cytoplasm and birefringence under polarized light, and it was then characterized as iridophorome. In the second case, in addition to the cells seen in the case of iridophoroma, neoplastic cells with black pigment in their cytoplasm were also observed, which were not birefringent under polarized light. Thus, through the clinical, anatomopathological and histopathological characteristics, it is concluded that the two reported cases of betta fish (Betta splendens) were diagnosed with iridophoroma and mixed chromatophoroma (irido melanophoroma)