Abstract
Myxosporean cysts were found in the mesentery, brain, liver, spleen, and pancreas of four mullets, Mugil cephalus, with spinal curvature, lordo-scoliosis, caught in a bay of Mie Prefecture, Japan. The cysts were most abundantly and frequently observed in the mesentery and brain. Although the cysts were distributed in various parts of the brain such as the 4th ventricle, the cavity of the optic tectum, the surface of the olfactory lobes and bulbs and the optic lobes, the 4th ventricle was the most common site of infection in all 4 fish examined. The cysts were spherical, about 1 mm in diameter. Dimensions (μm) of fresh spores : length, 10.5-12.5; width, 9.0-11.0; thickness, 6.0-7.5; polar capsule : length, 3.5-5.0; width, 2.5-3.5;polar filament : length, 19-39.Spores of the species were distinctly different from those of the other members of the genus Myxobolus on the basis of their shape, structure and dimensions examined by light and scanning electron micrography. Thus, we propose a new species Myxobolus spinacurvatura sp. n. for the present species.
