Some species of the genus myxobolus (Myxozoa: Myxosporea) infecting freshwater fish of the river nile,Egypt and the impact on their hosts

M.A. Ali National Institute of Oceanography and Fisheries, Cairo, Egypt K.A.S. AL-Rasheid (13) • F.A. Abdel-Ghaffar Department of Zoology, College of Science. King Saud University. P. O. Box 2455, Riyadh 11451, Saudi Arabia E-mail: krasheid@ksu.edu.sa Tel.: 1-966-1-4675758 Fax: +966-1-4678514 T. Sakran ■ A .A. Abdel-Baki Zoology Department. Beni-Suef Faculty of Science, Cairo University, Egypt F.A. Abdel-Ghaffar Zoology Department, Faculty of Science, Cairo University, EgyptSix Myxobolus species are described from Nile fish, five of which are new and one is redescribed: M. nqffari Abdel GhalTar et al., 1998 was recovered from the gills of Labeo niloticus and the mouth of Barbus hymn; M. caudatus sp. n. was observed in the tail fin of B. hymn; M. fahmii sp. n. occurred in the gills of B. bynni; M. imami sp. n. was found in the kidney of L. niloticus; M. intestinalis sp. n. was recorded from the intestine of B. bynni; and M. perforata sp. n. was found in the internal surface of the operculum of Hydrocynus fors-kalii. The histological effects of some of the Myxobolus infections present are described