Myxozoan infection in the muscle layer of the intestine of Rhamdia quelen from the Amazon River Basin, Brazil

Infecção por Myxozoa na camada muscular intestinal do Rhamdia quelen da Bacia do Rio Amazonas, Brasil

ABSTRACT:

The present study investigated the morphology and pathology associated with the occurrence of cysts caused byMyxobolus sp. in the intestine of the silver catfishRhamdia quelen . Comparisons with the otherMyxobolus species that infect the intestines of cyprinids and siluriforms revealed that the pyriform spores ofMyxobolus sp. are similar in shape to those described previously inM. miyairii, M. duodenalis andM. cunhai, but different in size. Morphometric analyses revealed that mature spores ofMyxobolus sp. (10.9 x 5.1μm) are smaller than those of most species exceptM. cunhai (10.0 x 5.0μm), which has been described infecting the Brazilian catfish Pimelodus clarias , although the spores differ morphologically in relation to the shape of the polar capsules. Further research is necessary in order to clarify the taxonomic and phylogenetic relationships among these congeneric species.

Key words:
Myxobolus; histopathology; fish parasites; catfish; neotropical