title: Morphological and ultrastructural characteristics of Myxobolus ridibundae n. sp. (Myxosporea: Bivalvulida) infecting the testicular tissue of the marsh frog Rana ridibunda (Amphibia: Ranidae) in Egypt.
abstract: Myxozoans are one of the most economically important groups of protozoan parasites causing many serious diseases of their hosts. In the present study, a total of 60 live adult male specimens of the marsh frog Rana ridibunda have been randomly captured during the period of January-December 2015 in different areas at Kafr El-Sheikh Governorate, Egypt and were examined for infection by myxosporidian parasites. A total of 48 (80.0 %) out of 60 frog specimens were found to be infected with Myxobolus species. Parasitic infection was restricted to the testicular tissue of the examined frogs. Macroscopic cysts (plasmodia) which heavily infested different parts of the testes were recovered. Morphological and ultrastructural characteristics of these myxosporidian species were carried out using light and transmission electron microscopy. Plasmodia measured 0.16-0.53 (0.34 ± 0.01) mm in diameter. Mature spores appeared oval in frontal view, measuring 8.9-11.5 (9.6 ± 0.1) μm in length and 7.5-9.1 (8.4 ± 0.1) μm in width containing 5-6 turns of polar filaments. Morphometric characterization revealed that the very small size of the present Myxobolus species was the most distinctive feature that separates them from all previously described Myxobolus species. Ultrastructural analysis showed that the plasmodia are surrounded by a plasma membrane with numerous pinocytotic protrusions extending toward the host cell. The generative cells and the different developmental stages are arranged at the periphery of the plasmodia, while immature and mature spores are centrally located. Sporogenesis, capsulogenesis, valvogenesis, and spore maturation of the present parasite are also described. The present species is described as Myxobolus ridibundae and represents a new species.
authors.affiliation: Zoology Department, Faculty of Science, Cairo University, Cairo, Egypt. fathyghaffar@yahoo.com.
authors.forename: Fathy
authors.initials: F
authors.lastname: Abdel-Ghaffar
authors.affiliation: Zoology Department, Faculty of Science, Cairo University, Cairo, Egypt.
authors.forename: Rewaida
authors.initials: R
authors.lastname: Abdel-Gaber
authors.affiliation: Zoology Department, Faculty of Women for Arts, Science and Education, Ain Shams University, Heliopolis, Egypt.
authors.forename: Sherein
authors.initials: S
authors.lastname: Maher
authors.affiliation: Zoology Department, Faculty of Women for Arts, Science and Education, Ain Shams University, Heliopolis, Egypt.|Biology Department, Faculty of Science-Yanbu, Taibah University, Medina, Saudi Arabia.
authors.forename: Nashwa
authors.initials: N
authors.lastname: El Deeb
authors.affiliation: Zoology Department, Faculty of Women for Arts, Science and Education, Ain Shams University, Heliopolis, Egypt.
authors.forename: Reem
authors.initials: R
authors.lastname: Kamel
authors.affiliation: Zoology Department, College of Science, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Saleh
authors.initials: S
authors.lastname: Al Quraishy
authors.affiliation: Parasitology Institute, Düsseldorf University, Düsseldorf, Germany.
authors.forename: Heinz
authors.initials: H
authors.lastname: Mehlhorn
mesh_terms: D000818:Animals; D004534:Egypt; D008297:Male; D055766:Myxobolus / Q000502:physiology* / Q000648:ultrastructure*; D010273:Parasitic Diseases, Animal / Q000469:parasitology*; D011895:Rana ridibunda / Q000469:parasitology*; D013170:Spores / Q000502:physiology / Q000648:ultrastructure; D013737:Testis / Q000469:parasitology*; D053833:Wetlands
keywords: Amphibia; Light and electron microscopy studies; Myxobolus spp.; Myxosporidia; Rana ridibunda