Phyllodistomum vaili(Plagiorchiida: Gorgoderidae) infecting Parupeneus rubescens (Perciformes: Mullidae): morphology and phylogeny.

Knowledge of the Arabian Gulf fish's parasite fauna is very poor. Until recently, only scattered reports from different locations are known for ecto- and endoparasites. Therefore, the present study aimed to investigate the digenean species that infects one of the most economically fish species in the Arabian Gulf, the rosy goatfish Parupeneus rubescens . One plagiorchiid species has been described, belonging to the Gorgoderidae family, and has been named as Phyllodistomum vaili Ho, Bray, Cutmore, Ward & Cribb, 2014 based on its morphological and morphometric characteristics. In order to accurately classify and characterize this plagiorchiid species, molecular analysis was carried out using both nuclear 18S and 28S rRNA gene regions and revealed that the present plagiorchiid species was associated with other species belonging to the Gorgoderidae family and deeply embedded in the Phyllodistomum genus, closely related to the previously described P. vaili (gb| KF013187.1, KF013173.1). The present study therefore revealed that the species Phyllodistomum is the first account as endoparasites from the rosy goatfish inhabiting the Arabian Gulf.

Phyllodistomum vaili(Plagiorchiida: Gorgoderidae) infecting Parupeneus rubescens (Perciformes: Mullidae): morphology and phylogeny / Phyllodistomum vaili (Plagiorchiida: Gorgoderidae) infectando Parupeneus rubescens (Perciformes: Mullidae): morfologia e filogenia

Abstract Knowledge of the Arabian Gulf fish's parasite fauna is very poor. Until recently, only scattered reports from different locations are known for ecto- and endoparasites. Therefore, the present study aimed to investigate the digenean species that infects one of the most economically fish species in the Arabian Gulf, the rosy goatfish Parupeneus rubescens . One plagiorchiid species has been described, belonging to the Gorgoderidae family, and has been named as Phyllodistomum vaili Ho, Bray, Cutmore, Ward & Cribb, 2014 based on its morphological and morphometric characteristics. In order to accurately classify and characterize this plagiorchiid species, molecular analysis was carried out using both nuclear 18S and 28S rRNA gene regions and revealed that the present plagiorchiid species was associated with other species belonging to the Gorgoderidae family and deeply embedded in the Phyllodistomum genus, closely related to the previously described P. vaili (gb- KF013187.1, KF013173.1). The present study therefore revealed that the species Phyllodistomum is the first account as endoparasites from the rosy goatfish inhabiting the Arabian Gulf.

Resumo O conhecimento da fauna de parasitas dos peixes do Golfo Árabe é escasso. Atualmente, apenas relatórios dispersos de diferentes locais são conhecidos para ecto e endoparasitas. Portanto, o presente estudo teve como objetivo investigar as especies digenéticas que infectam uma das espécies economicamente mais importantes do Golfo Arábico, o peixe-cabra rosado Parupeneus rubescens . Uma espécie de plagiorquídeo foi descrita, pertencente à família Gorgoderidae e foi denominada Phyllodistomum vaili Ho, Bray, Cutmore, Ward & Cribb, 2014, com base em suas propriedades morfológicas e morfométricas. A fim de classificar e caracterizar com precisão essa espécie de plagiorquídeo, a análise molecular foi realizada usando as regiões nucleares do gene 18S e 28S rRNA, revelando que a atual espécie de plagiorchídeo estava associada a outras espécies pertencentes à família Gorgoderidae e, profundamente incorporada ao gênero Phyllodistomum , intimamente relacionado ao P. vaili descrito anteriormente (gb - KF013187.1, KF013173.1). O presente estudo revelou, portanto, que a espécie Phyllodistomum vailli é o primeiro relato como endoparasita do peixe-cabra rosado que habita o Golfo Arábico.

Ultrastructure and phylogenetic characterization of the microsporidian parasite Heterosporis lessepsianus n. sp. (Microsporidia: Glugeidae) infecting the lizardfish Saurida lessepsianus (Pisces: Synodontidae) inhabiting the Red Sea.

Heterosporosis is an increasingly important microsporidian disease distributed worldwide, impacting wild and farmed-raised fish in both fresh and marine water environments. Twenty three out of 130 (17.69%) of the lizardfish Saurida lessepsianus were found to be naturally infected with microsporidian parasites. The rate of parasitic infection was increased during winter reaching 29.23% (19/65) and fall to 6.15% (4/65) in summer. The infection was recorded as numerous macroscopic whitish cysts reached 3.8-6.5 mm in diameter embedded in the abdominal cavity, skeletal muscles and mesenteric tissues of the infected fish inducing an enormous hypertrophy of infected tissues. Light microscopic examination revealed that parasitic foci were encapsulated by a host-derived fibrous membrane containing different developmental stages of the parasite. Spores were oval to pyriform in shape. Transmission electron microscopic study showed the presence of smooth membranes of the sarcoplasmic reticulum forming a thick, amorphous coat surrounding the various developmental stages of the examined parasite (meronts, sporont, sporoblasts, and spores). Mature spores were electron dense and uninucleate. The anchoring disk was found in a central position at the anterior end of the spore and a large vacuole was located at the posterior end. There was a definite number (7-8) of the polar filament turns. Molecular analysis based on the 16 small subunit (SSU) rDNA gene was performed to determine the phylogenetic position of the present parasite species. A 615 bp region of the 16SSU rDNA gene of the studied parasite was sequenced and deposited in GenBank under the accession number MF769371. Multiple sequence alignment demonstrated a high degree of similarity (>82%) with other twenty microsporidian species isolated from different aquatic hosts. The most closely related sequence was provided by the GenBank entry JF745533 for Heterosporis saurida isolated from the marine fish Saurida undosquamis with the highest percentage of identity (98%) and lowest divergence value (0.9). The ultrastructural characteristics and phylogenetic analysis support the recognition of a new species, herein named Heterosporis lessepsianus sp. n.

Morphological identification and molecular characterization of 18S rDNA of two hemiurid trematodes (Lecithocladium cristatum Rudolphi, 1819 and Lecithocladium parviovum Yamaguti, 1953) infecting the greater lizardfish Saurida tumbil (Pisces: Synodontidae) inhabiting the Red Sea.

A total of 100 specimens of the greater lizardfish Saurida tumbil were collected during the current investigation from the coasts of Hurghada City at the Gulf of Suez, Red Sea, Egypt; and necropsied to study their metazoan parasites. Of the total specimens collected, 32.0% were found to be naturally infected with hemiurid trematodes. The prevalence of parasitic infections increased to 48.0% during winter and fell to 16.0% during summer season with no mixed infections being observed. Two species of the hemiurid trematodes were recovered from the stomach of the infected fish samples; both belonged to the genus, Lecithocladium, in the family Hemiuridae. The morphometrics of their different body parts were characterized by light microscopy. Comparisons between the recovered parasites and previously studied species showed that the present investigation is the first report of Lecithocladium species infecting marine fish in the Red Sea. Additionally, molecular analysis of the parasites' 18S small subunit (SSu) rDNA was performed to determine their phylogenetic position in relation to previously recorded species in GenBank, which distinctly supported the morphological characteristics identified here. Two hemiurid species from the genus, Lecithocladium, to be L. cristatum and L. parviovum, were identified. Comparison of 18S rDNA sequences revealed that they had 98.0% sequence identity with L. excisum (gb| AJ287529) with a low divergence value. On the basis of these results, the two species isolated here were recorded within a new host and locality records in Egypt.

Light microscopic study of four plagiorchiid trematodes infecting marine fish in the south-eastern Mediterranean Sea, Alexandria City, with descriptions of two new species.

During the present investigation, a total of 220 fish specimens belonging to three different species, namely, little tunny Euthynnus alletteratus, African snook Lates niloticus, and striped red mullet Mullus surmuletus, were collected from January-November 2016 from the coasts off Abu Qir landing site, Alexandria City, south-eastern Mediterranean Sea, Egypt. The collected fish samples were dissected and examined for the presence of helminth parasites. Twenty-three out of 220 (10.45%) fish specimens were found to be naturally infected with four species of trematode parasites belonging to three different families of the order Plagiorchiida. The recovered parasite species were collected and identified by applying light microscopic examinations. The present study recorded two new parasite species, namely, Stephanostomum alletterani sp. nov. and Bathycreadium mulli sp. nov., belonging to the families Acanthocolpidae and Opecoelidae and infecting E. alletteratus and M. surmuletus, respectively and re-descriptions of the two remaining species, namely, Acanthostomum spiniceps and Aponurus mulli of the families Acanthostomatidae and Opecoelidae, respectively, to clarify the measurements of some body parts. Morphological and morphometric characterizations revealed some differences between the present species and other related species detected previously. Future studies are recommended to include advanced molecular characteristics for these species.

Morphological re-description and phylogenetic relationship of five myxosporean species of the family Myxobolidae infecting Nile tilapia.

Freshwater fish have a major economic and nutritional importance worldwide. Myxosporeans are highly dangerous parasites that infect different fish species, causing severe damage to a large number of economically important species, especially in aquaculture. We conducted a survey of myxosporean parasites infecting Nile tilapia Oreochromis niloticus (Perciformes: Cichlidae) collected from different localities along the River Nile passing through Giza province, Egypt. Out of 100 fish specimens collected, 45 were found to be naturally infected with these parasites in the region of the trunk kidney. Light microscopic examination revealed the presence of 5 distinct myxosporean species belonging to 2 different genera, viz. Myxobolus and Triangula, belonging to the family Myxobolidae; all 5 species have been previously described. Morphological characteristics, host specificity and geographical distribution, tissue tropism, and molecular analysis of the partial sequence of small subunit ribosomal DNA gene revealed that the recovered myxosporean species described herein were genetically distinct from other myxozoan species but had 95% sequence similarity to M. cerebralis. Also, phylogenetic analysis placed the present myxosporean species in the freshwater Myxobolus clade, which is a sister group of freshwater Myxobolus/Henneguya species.

Morphological description of Cosmocerca sp. (Nematoda: Cosmocerdidae) from the Mascarene grass frog Ptychadena cf. mascareniensis (Amphibia: Ptychadenidae). A light and scanning electron microscopic studies.

The Mascarene grass frog Ptychadena cf. mascareniensis is a species of frog with a vast area of distribution in Africa. A total of 300 frog specimens were collected from different localities at El-Giza province, Egypt; then dissected and examined for the presence of parasitic infection. Only eighty six (28.66%) specimens were found to be naturally infected with nematode parasite. Seasonally, the prevalence of infection was reached its maximum value of 74.66% during summer and minimum values of 26.66% (20/75), 13.33% (10/75) during spring and autumn, respectively; while no records were observed during winter season. The morphology of the recovered parasite was studied by using light and scanning electron microscopy. The adult worm characterized by anterior extremity with small mouth opening being surrounded by three lips provided with four sub-median cephalic papillae and one pair of lateral amphids. Body measurements showed that male worms were smaller than females measuring 1.22-2.43 (2.21 ± 0.1) mm in length and 0.21-0.34 (0.29 ± 0.01) mm in width. Females measured 1.9-3.7 (2.8 ± 0.1) mm in length and 0.24-0.42 (0.38 ± 0.01) mm in width. Comparing the present parasite with other species of the same genus described previously, several similarities were observed. However, peculiar new characteristics such as the arrangement of plectanes and somatic papillae, the presence of gubernaculum, the position of nerve ring, excretory pore, and vulval opening make it reasonable belongs to the family Cosmocercidae and identified as Cosmocerca sp. In addition, the present study was the first report for occurrence of cosmocercid species from the Mascarene grass frog in Egypt.

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.

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.

Morphological re-description and molecular characterization of Kudoa pagrusi (Myxosporea: Multivalvulida) infecting the heart muscles of the common sea bream fish Pagrus pagrus (Perciformes: Sparidae) from the Red Sea, Egypt.

In the present study, 100 samples of different sizes of the common sea bream fish Pagrus pagrus were collected from the Egyptian water along the Gulf of Suez, Red Sea and examined for the prevalence of myxosporidian parasites in general and Kudoa spp. in particular. Fish samples were thoroughly externally examined. After dissection, all the internal organs were removed and examined. A total of 60 out of 100 fish specimens were found to be infected with Kudoa stages. Parasitic infection was restricted to the heart muscles of the examined fish. None of the other organs was found to be infected. Macroscopic cysts (plasmodia) heavily infested the different parts of the heart muscles. Each plasmodium measured 1.2-2.5 (1.53 ± 0.2) mm × 0.63-0.80 (0.65 ± 0.2) mm. Mature spores are quadratic in shape in the apical view showing four equal valves and four symmetrical polar capsules. Fresh spores were 5.0-7.1 (5.7 ± 0.2) µm long × 5.4-8.5 (6.1 ± 0.3) µm wide. On the basis of spore morphology, the present species was identified as Kudoa pagrusi. Morphometric characterization revealed that the relatively small size of this Kudoa species was the distinctive feature that separates it from all previously described species. Molecular analysis based on small subunit ribosomal DNA (SSU rDNA) sequences revealed that the highest percentage of identity was observed with K. scomberomori and followed by K. shiomitsui, K. hypoepicarclialis, K. amamiensis, and K. kenti. The kudoid spores showed morphometric variations to some extents but had essentially identical nucleotide sequences of the SSU rDNA gene sequences closest to those of K. scomberomori and K. shiomitsui recorded from elasmobranchs in the Indo-Pacific Ocean. The present findings support the identification of an ancestral marine origin of the present Kudoa species.

Sarcocystis acanthocolubri sp. n. infecting three lizard species of the genus Acanthodactylus and the problem of host specificity. Light and electron microscopic study.

In the present investigation, macroscopic sarcocysts of Sarcocystis acanthocolubri were observed in muscles of 42 (4.3%) out of 975 Acanthodactylus sp. lizards collected from different geographical areas in Egypt. The infection rate was 6.4% in Acanthodactylus boskianus, 2.1% in Acanthodactylus sculentus, and 5% in Acanthodactylus paradalis. The highest infection rate was recorded in the lizards captured from Baltem (10% in A. boskianus and 8% in A. paradalis). The infection rate was usually higher in females (7.4%) than in males (3.8%). Moreover, the highest infection rate was recorded in summer (7.53%), autumn (3.57%), and spring (3.11%), and the lowest was recorded in winter (0.91%). Also, old animals had higher infection rates (10.8%) than young ones (0-2.7%). Macrocysts measured 0.95 × 10.12 mm. Both macroscopic and microscopic sarcocysts were enclosed only by a primary cyst wall, which had many finger-like, stalkless, and non-branched protrusions giving it a striated appearance. The primary cyst wall measured 3.9 µm. A dark granulated ground substance was found directly underneath the protrusions and is extended interiorly dividing the cyst cavity into many compartments containing the parasites (metrocytes and merozoites). Metrocytes were found directly under the ground substance and usually multiply asexually by endodyogeny producing two merozoites from each metrocyte. Both metrocytes and merozoites had the apical complex structures characteristic to the genus Sarcocystis. Transmission experiments with three snake species indicated that the snake Spalerosophis diadema is the proper final host belonging to the family Colubridae. The prepatent period was 16 days, while the patent period was 35 days. The results obtained from the present investigation revealed that this is a new species which was named Sarcocystis acanthocolubri.