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Seventy specimens of the gilthead sea bream Sparus aurata of the Red Sea were collected during the period from March to November 2013; they were dissected and examined for parasitic acanthocephalans. Only 40 (57.14 %) specimens were found to be naturally infected with Serrasentis sagittifer belonging to family Rhadinorhynchidae. The infection was recorded in the intestine, pyloric ceca, and the external surfaces of some internal organs of the infected fish. Seasonally, the prevalence of infection was increased to 77.14 % during summer season and decreased to 37.14 % during winter. Light and scanning electron microscopic investigation revealed that the adult worm was elongated (with broad anterior and narrow posterior ends) and measured 6.9-8.6 (7.6 ± 0.2) × 0.57-0.73 (0.63 ± 0.02) mm for male and 10.2-12.1 (11.5 ± 0.2) × 0.71-0.82 (0.76 ± 0.02) mm for female. Proboscis was long and cylindrical with a length of 0.97-1.6 mm (1.2 ± 0.2) for male and 1.12-1.17 mm (1.14 ± 0.02) for female. It was covered with numerous uniform spines arranged longitudinally as 9-11 rows each equipped by 15-18 spines. Spines were triangular, arrow-shaped, strong, and covered with cuticular theca; they decreased in size from the apex to the base of the proboscis. The proboscis is followed by a short spineless neck region followed by the body proper which is supported by multiple combs of spines (16-20) on its ventral surface. Molecular analysis of 18S rDNA sequence for the parasite demonstrated a close identity (>83 %) between the present acanthocephalan and other previously described species within class Palaeacanthocephala with 98 % identity with the previously recorded S. sagittifer (acc. no. JX014227) which is supported by the morphological data and the presence of trunk spines arranged within rows (comb-like) and the presence of four cement glands in the males. So, according to the records of morphological and molecular analyses, the present parasite is classified as S. sagittifer belonging to class Palaeacanthocephala and family Rhadinorhynchidae with a new host record from the gilthead sea bream S. aurata of the Red Sea. [ABSTRACT FROM AUTHOR]

In the present study, out of 200, 120 (60 %) Plectropomus maculates fish were found to be naturally infected with Kudoa sp. The infection was intensive and appeared as clusters of ovoid to ellipsoidal plasmodia being restricted to the cardiac muscles. More than 100 plasmodia were counted per infected heart and measured 1.53 ± 0.2 (1.2-2.5) × 0.65 ± 0.2 (0.63-0.80) mm. On the basis of spore morphology, the parasite was identified as Kudoa sp. The spore measures 4.8 ± 0.3 (4.7-6.8) × 4.0 ± 0.3 (4.6-6.5) μm. The four polar capsules were pyrifom in shape measuring 1.4 ± 0.2 (1.3-3.5) × 1.2 ± 0.2 (1.1-2.2) μm. Transmission electron microscopy showed that the plasmodia were bordered by a single membrane which invaginates into pinocytotic canals. Adjacent to the plasmodial wall, the generative cells and the early pansporoblasts were located peripherally. The developmental stages characterizing sporogenesis, capsulogenisis, and valvogenesis of the present parasites were ultrastructurally studied. [ABSTRACT FROM AUTHOR]

The spore morphology and molecular systematic of a new microsporidian which was isolated from the common sea bream Pagrus pagrus (F: Sparidae Linnaeus, 1758) from the Red Sea, Egypt have been studied. Fifty-six out of 300 (18.7 %) of this fish were infected with microsporidian parasites. The infection was appeared as whitish, ellipsoid, round, or elongated nodules embedded in the epithelial lining of the peritoneum and also in the intestinal epithelium. Light microscopic study revealed that nodules were encapsulated by a fibrous layer encircling numerous mature spores measuring 1.7 ± 0.6 (1.5-2.7 μm) × 1.5 ± 0.3 μm (1.2-1.8 μm) in size. Ultrastructure of spores was characteristic for the genus Pleistophora: dimorphic, uninucleate spores (each spore possesses three to five polar filament coils) and a posterior vacuole. Also, the early recognizable stages of the parasite within nodules include uninucleated, binucleated, and multinucleated meronts followed by detachment of the plasmalemma of the sporont producing sporoblasts which mature to spores that consist of a spore coat and spore contents. Also, we analyzed the small subunit ribosomal gene (SSUrDNA) using PCR and sequencing specimens from the marine populations of P. pagrus fish from the Red Sea. From blast searches, sequence analysis, and phylogenetic analysis, we did not find corresponding GenBank entries to our species. Comparison of the nucleotide sequences showed that the sequence of our microsporidium was most similar to five Pleistophora species with degrees of identity (>91.5 %). It was most similar (97.8 % identity) to that of Pleistophora hyphessobryconis (account no. GU126672) differing in 19 nucleotide positions and with lower divergence value, Pleistophora ovariae (96.2 % identity, account no. AJ252955), Pleistophora hippoglossoideos (91.9 % identity, account no. AJ252953), Pleistophora mulleri (91.9 % identity, account no. EF119339), and Pleistophora typicalis (91.9 % identity, account no. AJ252956). So, they likely represent new species named Pleistophora pagri sp. n. with accession number JF797622 and a GC content of 53 %. [ABSTRACT FROM AUTHOR]

Out of 600 marine fish from the Red Sea belonging to three different species that were collected and examined for microsporidian parasites, 87 (14.5%) fish were found to be infected. The infection was recorded as cysts or xenomas embedded in the gut epithelium and the peritoneal cavity of the three fish species. The highest percent of infection with microsporidian parasites was recorded in Saurida tumbil 19.5% (39/200) followed by Pagrus pagrus 15% (45/300) and the lowest percent of infection was recorded in Epinephelus chlorostigma 3% (three out of 100). After rupture of the cysts, the spores were released and examined by light microscopy. Each spore was elongated to ellipsoidal in shape and possessed a posterior vacuole which is characteristic to phylum Microspora. They measure 1.6 ± 0.5 μm (1.5-2.4 μm) × 1.3 ± 0.1 μm (1.3-2.0 μm) in Saurida tumbil and Pagrus pagrus, respectively. The spores of Pleistophora sp recorded from E. chlorostigma were ovoid to pyriform in shape and measure 1.9 ± 0.5 μm (1.8-2.7 μm) × 1.6 ± 0.4 μm (1.5-2.4 μm). [ABSTRACT FROM AUTHOR]

A new species of Microsporidia found in the marine teleost Sparus aurata collected from Hurghada coasts along the Red Sea, Egypt was described based on light and ultrastructural studies. Twenty three (30.6 %) out of 75 of the examined fish were parasitized with a microsporidian parasite. Numerous macroscopic whitish cysts embedded in the peritoneal cavity were observed to infect many organs of the body including muscles, connective tissues, and the intestinal epithelium. The infection was developed as tumor-like masses of often up to 5 mm in diameter inducing an enormous hypertrophy to the infected organs. Fresh spores appeared mostly ovoid to pyriform in shape reaching a size of 1.7 ± 0.5 (1.5-2.5) μm × 1.3 ± 0.4 (1-2) μm; they possessed a large vacuole at the posterior end. These spores were located within a sporophorous vesicle which was bound by a thick amorphous wall. The ultrastructural features support the placement of the present species within the genus Microsporidium. The developmental stages were enclosed within a xenoma structure that was bounded by a double-layered cyst wall. The life cycle of the microsporidian pathogen described herein included four stages: proliferation (merogony), sporogony, sporoblast, spores, and liberation. Mature spores appeared electron dense, uninucleate, and were ellipsoidal in shape. At the anterior end of the spore, the anchoring disk was found in a central position. There was a definite number (5-11) of turns of the polar tube. A 538-bp region of the SSU rDNA gene of the studied species was sequenced (GenBank accession number: KF0220444). Multiple sequence alignment calculated a high degree of similarity (>92 %) with six microsporidian species. The most closely related sequence was provided by the GenBank entry AF151529 for Microsporidium prosopium isolated from Hyperoplus lanceolatus differing in 67 nucleotide positions in its SSU rDNA with the highest percentage of identity (97.2 %) and the lowest divergence value (0.20). Variations in the morphology of the spores and developmental stages between the two species revealed that the two species are different. The site of infection in the host and description of the onset of parasite development are strong criteria for the placement of the microsporidian parasite of the fish S. aurata within the genus Microsporidium as a new species, and we propose to name it Microsporidium aurata nov. sp. [ABSTRACT FROM AUTHOR]

The present study was the first investigation of digenetic trematode parasites of Saurida tumbil, a commercially important fish species of the Red Sea, during the period from January to December 2011. Thirty-nine out of 103 (37.8 %) of the examined fish were found to harbor the digenetic trematode Lecithochirium grandiporum (family: Hemiuridae) infecting the pyloric portion of stomach and middle part of intestines of the lizard fish. The morphology and morphometric characterizations of this digenetic trematode were described by light and scanning electron microscopy. The parasite possessed a body which was elongated and rounded anteriorly, but truncated posteriorly, and its body measured 1.63 ± 0.20 (1.2-1.93) mm (invaginated ecsoma), 2.11 ± 0.20 (1.83-2.35) mm (evaginated ecsoma) in length with a maximum width of 0.4 ± 0.02 (0.31-0.52) mm at ovarian level. They were characterized by a subterminal oral sucker which measured 0.15 ± 0.02 (0.12-0.18) mm in diameter and was smaller than the ventral sucker which was circular and large with a wide aperture, hence the specific name grandiporum. A multilobated digitiform vitellarium which was a distinctive feature for this species was also observed. The number of parasite per fish was one to six. Prevalence and intensity of infection were positively correlated with host size (increasing with host size increasing). Host sex does not seem to affect the prevalence of infection. The present study was considered as a first record from the Red Sea in Egypt. [ABSTRACT FROM AUTHOR]

Abstract??A new myxosporean,Zschokkella egyptican. sp. was found in the gallbladder of two hosts: the eel catfishPlotosus lineatusand the freckled goat fishUpeneus tragulafrom the Red Sea at Suez City, Egypt. The plasmodia were polysporic, kidney to elliptical shaped with hairy holdfast projection and measured 109???70??m. Mature spores were fusiform with 9 to 11 longitudinal striations. The mean spore dimensions were 13.0???10.5??m. Spherical polar capsules are 4.8??m in diameter; the polar filament showed four turns and were arranged perpendicular to the longitudinal axis of the capsule. [ABSTRACT FROM AUTHOR]