Ultrastructural characterization of Pleistophora macrozoarcidis Nigerelli 1946 (Microsporidia) infecting the ocean pout Macrozoarces americanus (Perciformes, Zoarcidae) from the gulf of Maine, MA, USA.

Pleistophora macrozoarcidis a microsporidian parasite infecting the muscle tissue of the ocean pout Macrozoarces americanus collected from the Gulf of Maine of the Atlantic Ocean, MA, USA, was morphologically described on the basis of ultrastructural features. Infection was detected as opaque white or rusty brown lesions scattered throughout the musculature of the fish mainly in the region anterior to anus. Transmission electron microscopy showed that in individual parasitized muscle cells, the infection progresses within parasite formed vesicles which are in direct contact with muscle cell elements. The earliest observed parasitic stages are the globular multinucleated proliferative cells or plasmodia limited by a highly tortuous plasmalemma with intervesicular finger-like digitations projecting into the parasite cytoplasm. These cells divided through the invagination of the plasmalemma and the amorphous coat producing daughter-cells. Fine electron-dense secretion is deposited on the plasmalemma that causes its thickening which is a sign of commencement of the sporogonic phase. This phase is carried out by cytokinesis of the sporonts and results in the formation of sporoblasts and finally spores. Mature spore has a thin electron-dense exospore, a thick electron-lucent endospore, and the plasma membrane which encloses the spore contents. A single nucleus is centrally located with the posterior region containing a posterior vacuole. The majority of spores have 7-13 coils in 1-2 rows, and a small group of spores had about 23 coils forming two rows. Events of polar filament extrusion for penetration of uninfected cells were studied. The polaroplast membranes were expanded and occupy most of the length of the spore. The coils are dislocated from the sides of the spore to throughout the entire sporoplasm. The polar filament everts and extrudes through the polar cap with a sufficient force to pierce adjacent sporophorous vesicle walls. After eversion, the polar filament is referred to as a polar tubule, as it forms a tube through which the sporoplasm travels. It pierces anything in its path and deposits the sporoplasm at a new location to begin another infective cycle.

Description of two equine nematodes, Parascaris equorum Goeze 1782 and Habronema microstoma Schneider 1866 from the domestic horse Equus ferus caballus (Famisly: Equidae) in Egypt.

Parasitic gastroenteritis (PGE) caused by infection of the gut with parasitic nematodes is one of the most important diseases of livestock animals from both financial and welfare perspectives. Parascaris equorum and Habronema microstoma are of the most endemic nematodes of the world which are currently the major cause of PGE of the domestic horses in Egypt. The present investigation introduced the first morphological description of these nematodes recovered from the domestic horse, Equus ferus caballus (Equidae), in Egypt by light and scanning electron microscopy. Seven P. equorum (fifth stage) and 18 adults of H. microstoma were recovered from the gastrointestinal tracts of four young domestic horses collected during the year of 2015. Microscopic examination of the isolated fifth stage P. equorum revealed that it possessed a long body with a broad anterior end equipped by large shamrock-like lips with deep transverse groove on medial surface set off from the rest of the body by a deep post-labial constriction giving the body a shouldered appearance. The total body length was 12-15 (14 ± 2) cm for males and 13-18 (16 ± 2) cm for females. Lips were three in number in the form of one dorsal and two sub-ventral surrounding the central stoma. The isolated adult worms of H. microstoma were whitish in color narrowed slightly at the anterior end. Single lateral ala in the cephalic region in both sexes was observed. The buccal vestibule was markedly thickened and equipped by two tridentate teeth. The adult worms had two bilobed lateral lips surrounding the mouth with four sub-median cephalic papillae and two amphids. The males were 14.5-18.0 (17.2 ± 0.3) mm long and 1.23-1.57 (1.42 ± 0.3) mm wide. The posterior end was spirally coiled and had wide caudal alae. The spicules were unequal. The females were 13.5-21.0 (16.2 ± 0.3) mm long and 1.55-1.75 (1.69 ± 0.3) mm wide. The anal pore had a thin upper rim and was located 177.0 µm from the posterior end.

New host records of three juvenile nematodes in Egypt: Anisakis sp. (Type II), Hysterothylacium patagonense (Anisakidae), and Echinocephalus overstreeti (Gnathostomatidae) from the greater lizard fish Saurida undosquamis of the Red Sea.

Three juvenile nematode parasites were collected naturally from 90 (75 %) out of 120 specimens of the marine greater lizard fish Saurida undosquamis captured from water coasts at Hurghada City along the Red Sea in Egypt during the period from September 2013 to April 2014. Worms were identified on the basis of light and scanning electron microscopy. Two of the recovered worms were isolated from the peritoneal cavity of the infected fish around the wall of the stomach as encapsulated larvae. The anisakid juvenile Anisakis sp. (Type II) was characterized by an anteroventrally triangular mouth, with a boring tooth; its postanal tail was rounded, without a terminal mucron or spine. The gnathostomatid Echinocephalus overstreeti was characterized by the presence of a cephalic bulb armed with six transverse rows of spines which were slightly more compact near the anterior end of bulb with maximal separation near the midbulb; the cephalic bulb terminated at a pseudolabia which situated dorsoventrally and reached its greatest width at the posterior one third of the body, The postanal tail terminated at a pointed mucron. The third juvenile species, Hysterothylacium patagonense (Anisakidae), was isolated from the intestine of the infected fish; they are characterized by a small-sized body with a conical tail provided by a nodulose apex, and the anterior end was equipped with three lips. A dorsal lip slightly smaller than the two subventrals left a deep postlabial groove and prominent lateral flanges in between, and the proximal part of each lip was smooth. The three described species were compared morphologically and morphometrically with some of the previously recorded species of the same genus. From this comparison, the similarity and variations between these species were described and concluded that the present study should be considered as a new host record in Egypt.

Hysterothylacium aduncum (Nematoda, Anisakidae) with a new host record from the common sole Solea solea (Soleidae) and its role as a biological indicator of pollution.

Hysterothylacium aduncum (Nematoda, Anisakidae) was isolated from the intestine of the common sole Solea solea (Family, Soleidae) collected from coasts along Alexandria City at the Mediterranean Sea in Egypt, during the period from May to September 2013. Light and scanning electron microscopy revealed that this nematode parasite belongs to the family Anisakidae in the genus Hysterothylacium. The type species is named H. aduncum, based on the presence of three interlocked lips with the interlabium in between, the presence of cephalic papillae, and large numbers of caudal papillae in males. Body measurements showed that the male worms were smaller than females measuring 13.9-18 mm (16.2 ± 0.2) in length and 0.26-0.34 mm (0.30 ± 0.01) in width. Females measured 20.5-24.5 mm (22.7 ± 0.2) in length and 0.41-0.52 mm (0.45 ± 0.01) in width. The morphological characteristics of this species was confirmed by molecular analysis of 18S rDNA for these parasites followed by comparison between sequence data for them with those obtained from the Genbank showing that H. aduncum is deeply embedded in the genus Hysterothylacium with a sequence similarity between 95.5-94.3 % with close relationships to other H. aduncum specimens and Hysterothylacium sp.. Furthermore, it was shown that this parasitic nematode is able to accumulate larger concentrations of heavy metals such as Fe, Cu, Cd, and Ni within its tissues than of its host fish and thus it can be used as a useful bio-indicator of water pollution.

Molecular characterization and new geographical record of Lecithochirium priacanthi (Digenea: Hemiuridae) infecting the moontail bullseye fish Priacanthus hamrur (Perciformes: Priacanthidae) from the Red Sea, Egypt.

Sixty specimens of the moontail bullseye Priacanthus hamrur were collected at Coasts of Suez Gulf, Red Sea (Egypt) during the four different seasons of the whole year 2014 and necropsied to study the infection with metazoan parasites. Twenty-one out of 60 examined fish specimens (infection rate of 33.33 %) were found to be naturally infected by the hemiurid digenean parasite Lecithochirium priacanthi. The large-sized fish reaching 15-30 (23.5 ± 4.8) cm were more intensively infected than the smaller ones. A definite seasonal effect was observed as winter was found to be the season of severe parasitic infections, while midsummer was the lowest one. The morphological and morphometric characterization of this parasite were examined by light and scanning electron microscopy. The adult worms had an elongated body measuring 1.93-2.54 (2.11 ± 0.20) mm in length and 0.61-0.72 (0.67 ± 0.02) mm in width. The body was characterized by the presence of a sub-terminal oral sucker with diameters reaching 0.12-0.16 (0.14 ± 0.02) mm. The ventral sucker measured 0.32-0.45 (0.38 ± 0.02) mm in diameter. The body was supplied by a short retracted portion with a blunt end that measured 0.48-0.61 (0.56 ± 0.02) mm in length and 0.28-0.35 (0.32 ± 0.02) mm in width. Morphological results of the present parasite were compared with other related species described previously from Perciformes. Molecular characterization based on small subunit ribosomal DNA was done to confirm the obtained morphological and morphometric results. A preliminary genetic comparison between SSU rDNA of this parasite and other species of Hemiuridae places the present specimen as a putative sister taxon to Lecithochirium grandiporum and Lecithochirium caesionis. The finding of L. priacanthi in Egyptian marine water fish represents a new geographical record for this parasite.

Twelve myxosporean species of the family Myxobolidae infecting freshwater fishes of the River Nile, Egypt, with the description of four novel species.

Myxosporidian parasites infecting fish are very dangerous parasites causing severe damage to a large number of economically important fishes especially in aquaculture. A survey of myxosporean parasites infecting four species of fishes from the River Nile in Egypt is conducted. One hundred and ninety-five out of 316 fish specimens with a percentage of 61.7% were found to be naturally infected with these parasites. Light microscopic examination of different tissues revealed the presence of 12 myxosporean species belonging to the family Myxobolidae. Four of the identified species are novel and the other eight species are redescribed. Myxidium sp.nov. a coelozoic species inhabiting the gallbladder of Labeo niloticus with its mature spores float free in bile was detected. These spores possess a fusiform, straight, or slightly crescentic shape with less pointed ends and two equal polar capsules. Three novel histozoic Myxobolus species infecting Oreochromis niloticus were identified. Myxobolus sp(1).nov. is a species inhabiting kidney tissue with ovoid spores exhibiting a small intercapsular appendix. Myxobolus sp(2).nov. and Myxobolus sp(3).nov. recovered from kidney and intestinal tissues. Spores of Myxobolus sp(2).nov. are elliptical in shape with an anterior end wider than posterior one. Their two polar capsules are ovoid to pyriform occupied nearly the first third of the spore body. Spores of Myxobolus sp(3).nov. are broader than long with nearly rounded or ovoid two polar capsules. Eight species of the recovered myxosporean parasites are redescribed, Myxobolus niloticus Fahmy et al., 1971 from pectoral, dorsal, and tail fins of L. niloticus, Henneguya suprabranchiae Landsberg, 1987, and Henneguya branchialis Ashmawy et al., 1989 are recovered from the gills and suprabranchial organ of the catfish Clarias gariepinus, respectively, Myxobolus naffari Abdel-Ghaffar et al., 1998 and Myxobolus imami Ali et al., 2002 are found in the kidney of Barbus bynni and L. niloticus, Myxobolus caudatus Ali et al. & Parasitol Res (2002) from Tail fin of B. bynni, Myxobolus fomenai Abdel-Ghaffar et al., 2008 from kidney and intestinal tissues of O. niloticus, Thelohanellus niloticus Abdel-Ghaffar et al., 2012 are observed in the gills of L. niloticus.

Haemonchus longistipes Railliet & Henry, 1909 (Nematoda, Trichostrongylidae) from the Egyptian dromedary, Camelus dromedarius (Artiodactyla: Camelidae), first identification on the basis of light and ultrastructural data.

Haemonchus longistipes is a gastrointestinal abomasal nematode which is one of the most prevalent and pathogenic parasites infesting the stomach of ruminants. On the basis of light and ultrastructural data, the objective of the present study was to introduce a first identification of the cameline haemonchosis caused by H. longistipes. Abomasa of 42 Egyptian camels Camelus dromedarius (Artiodactyla: Camelidae) were collected monthly from September 2013 to April 2014 from the main slaughter house of Cairo, Egypt. Adult male and female nematode worms were recovered from 26 (62%) specimens of the examined abomasa. The parasites were of yellow color; the body was filiform (slender) tapered towards the anterior end in male and towards both ends in female. Buccal capsules absent, the buccal cavity was small with a conspicuous dorsal lancet extended from dorsal wall. The cervical papillae were prominent and spine-like. The body length of the female worm was 16.6-20.5 (18.5 ± 0.3) mm. The anterior end to the cervical papillae was 3.19-4.30 (4.12 ± 0.5) mm. The vulva of the female had a linguiform process or flap, the tail is without a spine, and the anal pore at the posterior end of the body had a simple dorsal rim. The body of male was 10.4-14.7 (13.9 ± 2.0) mm in length. The male bursa had elongated lobes supported by long, slender rays. The small dorsal lobe was asymmetrical with Y-shaped dorsal rays. The spicules were long with a length of 0.52-0.54 (0.53 ± 0.05) mm, each provided with a small barb and pore near its extremity. Synlophe was bilaterally and dorsoventrally symmetrical; it extended from cephalic expansion over anterior 50% of prebursal or prevulvar body and consisted of a maximum of 42 ridges. The described species herein was compared with the three morphologically similar species Haemonchus mitchelli, Haemonchus okapiae, and H. longistipes with their synlophes consist of 42 ridges distributed over the anterior half of the body. These species can be separated by unique structural characteristics of their synlophes, spicules, and copulatory bursa. The most morphologically similar species to the recovered worm was H. longistipes. Also, some of the parameters with regard to morphology and morphometry of this parasite were described for the first time.

Sarcocystis schneideri n. sp. (Sarcocystidae) infecting the barber skink Eumeces schneideri schneideri (Scincidae) Daudin, 1802. A light and ultrastructural study.

The current study provides the first record of infection with Sarcocystis species in the barber skink Eumeces schneideri schneideri (Scincidae) captured from the north region of Egypt around the cities of El-Hamam and Al-Dabaa, Mersa Matruh Governorate, Egypt. Morphology of the parasite cysts was described using light and transmission electron microscopy. Five out of 80 (6.25%) of the examined skinks were found to be infected. The infection was recorded firstly by light microscopy as spindle-shaped cysts embedded in the muscle tissue. The cysts were microscopic and measured 250-900 µm in length × 50-100 µm in width (mean, 575 × 75 µm). The validity of this species was confirmed by means of ultrastructural characteristics of the primary cyst wall (0.28 µm thick) which revealed the presence of irregularly shaped crowded and osmiophilic knob-like projections underlined by a thin layer of ground substance measuring 0.15-0.17 µm (mean, 0.16 µm). This layer consisted mainly of fine, dense homogenous granules enclosing the developing metrocytes and merozoites that usually contain nearly all the structures of the apical complex and fill the interior cavity of the cyst. Several septa derived from the ground substance divided the cyst into compartments. The merozoites were banana-shaped and measured 3-5 µm in length and 1.5-2.5 in width with centrally or posteriorly located nuclei. The morphological and morphometric data obtained during study were compared with those recorded previously from organisms within the Scincidae family. It was observed that this parasite possessed some distinguishing characteristics from the comparable species, which should be considered as a new species of the Sarcocystis genus, and the proposed name was Sarcocystis schneideri n. sp. with new host and locality records in Egypt.

Sarcocystis arieticanis (Apicomplexa: Sarcocystidae) infecting the heart muscles of the domestic sheep, Ovis aries (Artiodactyla: Bovidae), from K. S. A. on the basis of light and electron microscopic data.

In the present study, the heteroxenous life cycle of Sarcocystis species from three strains of the slaughtered sheep at Al-Azizia and Al-Saada abattoirs in Riyadh city, K.S.A., was studied. Muscle samples of the oesophagus, diaphragm, tongue, skeletal and heart muscles were examined. Varied natural infection rates in the muscles of the examined sheep strains were recorded as 83% in Niemy, 81.5% in Najdy and 90% in Sawakny sheep. Muscles of the diaphragm showed the highest infection level above all organs except Najdy sheep in which oesophagus has the highest rate. Also, the heart was the lowest infected organ (40% Niemy, 44% Najdy and 53% Sawakny). Microscopic sarcocysts of Sarcocystis arieticanis are easily identified in sections through the heart muscles of the domestic sheep Ovis aries (Artiodactyla: Bovidae). Cysts measured 38.5-64.4 µm (averaged 42.66 µm) in width and 62.4-173.6 µm (averaged 82.14 µm) in length. The validity of this species was confirmed by means of ultrastructural characteristics of the primary cyst wall (0.1-0.27 µm thick) which revealed the presence of irregularly shaped crowded and hairy-like projections underlined by a thin layer of ground substance. This layer consisted mainly of fine, dense homogenous granules enclosing the developing metrocytes and merozoites that usually contain nearly all the structures of the apical complex and fill the interior cavity of the cyst. Several septa derived from the ground substance divided the cyst into compartments. The merozoites were banana-shaped and measured 12-16 µm in length with centrally or posteriorly located nuclei. Experimental infection of carnivores by feeding heavily infected sheep muscles revealed that the dog, Canis familiaris, is the only final host of the present Sarcocystis species. Gamogony, sporogonic stages and characteristics of sporulated oocysts were also investigated.

Cucullanus egyptae sp. nov. (Nematoda, Cucullanidae) infecting the European eel Anguilla anguilla in Egypt. Morphological and molecular phylogenetic studies.

A total of 80 specimens of the European eel Anguilla anguilla were collected during the period from February 2013 to March 2014 at the coast of the Gulf of Suez (Red Sea, Egypt). A new species of parasitic nematodes was recovered and described as Cucullanus egyptae. It was found in the eel's intestine with a prevalence of 68.7%. The morphology of the recovered parasite was studied by light and scanning electron microscopy. The adult worms had a wide cephalic extremity with a slit-like oral aperture being surrounded by a cuticular ring and delimited internally by a row of small teeth in addition to four sub-median cephalic papillae and one pair of lateral amphids. Body measurements showed that the male worms were smaller than females measuring 7.5-8.9 mm (8.3 ± 0.2) in length and 1.6-1.9 mm (1.8 ± 0.1) in width. Females measured 12.9-13.5 mm (13.1 ± 0.2) in length and 2.9-3.2 mm (3.1 ± 0.1) in width. The posterior end of the males is provided with ten pairs of caudal papillae and two long spicules which are slightly sclerotized, equal in size measuring 0.59-0.65 mm (0.62 ± 0.01) in length. Comparing the present worms with other species of the genus Cucullanus, several similarities were observed. However, peculiar new characteristics such as the precloacal sucker (especially the spicula length), the arrangement and the distribution of the post-cloacal papillae, and the position of the excretory pore make it reasonable to describe a new species. The sequence data of the small subunit (SSU) ribosomal DNA (rDNA) obtained from the present nematode supported its taxonomic position within the genus Cucullanus. The new species is closely related to the first clade of Spirurina and even more closely related to Cucullanus dodsworthi as a sister taxon with a high percentage of identity. The sequence of the recorded SSU rDNA of this parasite is deposited in the GenBank with the accession no. KF681520. It is proposed to name the new species C. egyptae as the first representative of Cucullanidae in Egypt with a new host record.

Immune response, oxidative stress, and histological changes of Wistar rats after being administered with Parascaris equorum antigen.

Worldwide, particularly in developing nations, helminth infections are the leading causes of livestock illness and mortality. Parascaris (P.) equorum, a parasitic worm from the Ascarididae family, significantly impacts the production, health, and working performance of equines. This study aimed to investigate the impact of intraperitoneal sensitization of P. equorum on the immune system, oxidative stress, and histology in Wistar rats. After acclimatization for 7 days, we divided the rats into five groups, each consisting of six rats. Group I, serving as the control, was administered distilled water, followed by groups II (day 7), III (day 14), IV (day 21), and V (day 33). The rats were euthanized every day mentioned (Days 7-33). On day 0, a dosage of 1ml/100 gm rat (containing 500 µg/ml protein content) emulsified crude antigen extract with an incomplete Freund's adjuvant (1:1 volume), followed by a second dose of the same antigen concentration on day 7. To assess the allergenicity of this nematode, we measured a whole blood profile, serum levels of IFN-γ, IL-5, IL-10, IL-13, and IL-33, total immunoglobulins IgE and IgG, and oxidative stress markers. Also, we examined histological changes in the liver, kidney, and spleen. The results showed that values of total leukocyte count, granulocytes, monocytes, and lymphocytes were significantly (P < 0.05) increased on day 14 post-infection relative to other days of investigation. It was found that the levels of total immunoglobulins (IgE and IgG) and cytokines (INF-γ, IL-5, IL-13, and IL-33) on days 14 and 21 were significantly higher than in the control group. At all periods of the experiment, the injected group exhibited significantly higher concentrations of MDA and NO compared to the control group (P < 0.05). Conversely, GSH and CAT levels (P < 0.05) dropped significantly on days 7, 14, and 21. Different rat tissues showed alterations. Ultimately, this study described the detrimental effects of P. equorum crude antigen administration on the immune system, oxidative states, and histological changes of Wistar rats at various intervals.

Morphological and phylogenetic description of a new xenoma-inducing microsporidian, Microsporidium aurata nov. sp., parasite of the gilthead seabream Sparus aurata from the Red Sea.

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.

New host and locality records of two nematode parasites Dujardinnascaris mujibii (Heterocheilidae) and Hysterothylacium aduncum (Anisakidae) from the common seabream Pagrus pagrus: a light and scanning electron microscopic study.

In the present study, the morphology and morphometric characterization of Dujardinnascaris mujibii (Heterocheilidae) and Hysterothylacium aduncum (Anisakidae), new nematode parasites infecting the sea bream Pagrus pagrus (Osteichthyes, Sparidae), were described for the first time from the Gulf of Suez and Hurghada City of the Red Sea, Egypt. Ninety-eight (70 %) and 62 (44.2 %) out of 140 of the examined fish were naturally infected with these nematodes, respectively. The infection was investigated macroscopically by the occurrence of these parasites in the flesh, stomach, intestines, as well as their body cavities as adult and larval stages. D. mujibii is characterized by an elongated body with a length of 36.4 ± 3 (23-38) mm (female) and 20 ± 3.0 (17-24) mm (males); the head is provided with three prominent lips each with four teeth like structures and the apical lip is embossed with a regular zigzag pattern as revealed by SEM. Interlabia were present, with prominent grooves. Juvenile stage is smaller than adults and provided with a spiny mucron. H. aduncum was small, measured 22.5 ± 2.0 (20.0-24.3) mm in length (female) and 16.3 ± 2.0 (14.5-17.4) mm (male). The head region bears three large lips which were clearly separated from each other, with the apical one having two rounded ends and the space between the two adjacent lips occupied by very prominent interlabia. The present study represents new host and locality records from P. pagrus fish in Egypt.

Morphological and phylogenetic analysis of Echinocephalus carpiae n. sp. (Nematoda: Gnathostomatidae) infecting the common carp Cyprinus carpio inhabiting Burullus Lake--a new host record in Egypt.

The present study described a new species of the genus Echinocephalus that was isolated from the intestine of the common carp Cyprinus carpio inhabiting Burullus Lake, Kafr el-Sheikh Governorate, Egypt. Thirty-two out of 70 examined specimens (45.71 %) were found to be naturally infected. The adult male worms were elongated and measured 0.79-0.85 mm (0.81 ± 0.02) in length and 0.21-0.32 mm (0.28 ± 0.002) in width, while females reached 0.89-0.98 mm (0.9 ± 0.02) long and 0.25-0.38 mm (0.28 ± 0.002) wide. The reported species are investigated microscopically, genetically, and compared with previous related ones. The present study recorded this new nematode parasite as Echinocephalus carpiae with accession no. KC493258, inhabiting new host and locality records in Egypt. It is especially characterized by short body length, cephalic bulb with few (six to eight) multiple rows of spines, clear annulated cuticle, and new genetic sequences, which identify the paraphyly of Gnathostomatinae.

Morphological and molecular characterization of Lecithochirium grandiporum (Digenea: Hemiuridae) infecting the European eel Anguilla anguilla as a new host record in Egypt.

In the present study, the morphological and molecular characterization of Lecithochirium grandiporum, a digenetic trematode infecting the European eel Anguilla anguilla (Family (F): Anguillidae), were described for the first time from Burullus Lake, Kafr El-Sheikh Governorate, Egypt. Twenty-five out of 60 specimens (infection rate of 41.66%) were found to be naturally infected. Infection was recorded as small worms attached to the inner wall of the intestine of host fish. Adult worms measured 1.59 ± 0.20 (1.3-1.85) mm long and 0.3 ± 0.02 (0.29-0.48) mm wide for everted specimens with a smaller oral sucker measuring 0.15 ± 0.02 (0.13-0.18) mm, and a larger ventral sucker which was 0.16 ± 0.02 (0.14-0.25) mm. Our results recorded morphological differences as smaller dimensions of different body parts and the smaller oral/ventral sucker ratio between Lecithochirium fusiforme and L. grandiporum. Also, the phylogenetic position of the worm was determined by molecular characterization of their 18 SSU rDNA. Results were compared with those of previously recorded species on the Gene Bank. It was found that the present species coincide with those belonging to genus Lecithochirium. Comparison of the nucleotide sequences and divergence showed that the SSU rDNA gene of this Lecithochirium species revealed 92 % sequence identity with L. fusiforme (accession no. DQ413192) differing in 26 nucleotides with lower divergence value. According to these results, this study indicated that the present species is recorded as L. grandiporum with accession no. KC166146 as a parasite with new host and locality records in Egypt.

First identification of four trypanorhynchid cestodes: Callitetrarhynchus speciouses, Pseudogrillotia sp. (Lacistorhynchidae), Kotorella pronosoma and Nybelinia bisulcata (Tentaculariidae) from Sparidae and Mullidae fish.

Four previously unrecognized trypanorhynchids are described based on fish specimens from Sparidae and Mullidae host fish of the Red Sea. From September 2010 to June 2011, 66 specimens of the sea bream Pagrus pagrus (F: Sparidae) and 43 of the red mullet Mullus barbatus (F: Mullidae) were purchased from markets in the Suez and Hurghada cities of the Red Sea. The fishes were measured, and their organs investigated for helminth infections. Forty-one (37.6 %) out of the 109 fish specimens investigated were parasitized with Trypanorhyncha metacestodes, identified as Callitetrarhynchus speciouses Linton 1897, Pseudogrillotia sp. Dollfus 1969, Kotorella pronosoma Stossich 1901 from P. pagrus, and Nybelinia bisulcata Linton 1889 from M. barbatus in the mesentery and peritoneal cavity, with prevalences of 16.5, 11.0, 6.0, and 12.0 %. All of these larval stages were encapsulated larvae in blastocysts. C. speciouses is characterized by an elongated scolex, two bothria, a long postbulbosa, and four elongated bulbs. Pseudogrillotia sp. possesses a scolex with two lateral patelliform bothridia; posterior margins are free, not notched. A long sheath was observed, which was irregularly coiled when tentacles invaginated. N. bisulcata possesses an acraspedote scolex with four bothridia, which are broad, bean-shaped. The tentacles are spirally coiled, supplied with hooks with abruptly turned points. The four tentacles sheaths rose from scolex as two anterior (front) and two posterior (back) which overlap at the apices of bulbs. K. pronosoma is characterized by a short body with a craspedote scolex and four bothridia. The tentacles are short and emerge pairwise. The presence of Trypanorhyncha metacestodes in the muscles does not represent a risk of infection for humans. They have a negative effect on fish esthetics. The repugnant aspect and the prohibition for commercial use by sanitary inspectors, however, cause consumer rejection. Parasites of the order Trypanorhyncha have been recorded in these host fishes for the first time.

Thelohanellus niloticus sp. nov. (Myxozoa: Myxosporea), a parasite of the Nile carp Labeo niloticus from the River Nile, Egypt.

In the present study, the morphology and morphometric characterization of Thelohanellus niloticus sp. nov., a new myxozoan belonging to genus Thelohanellus Kudo, 1933 (Myxosporea, Bivalvulida) infecting the gills of Labeo niloticus (Osteichthyes, Cyprinidae), were described for the first time from the River Nile at El-Minia Governorate, Egypt. Forty-one out of 78 (52.6 %) of the examined fish were infected. The infection was observed as irregular, milky whitish, cyst-like plasmodia (up to 0.8 mm in diameter) attached to the gill filaments of the host fish. These plasmodia contained tear-shaped myxospores with slightly tapering anterior and rounded posterior ends. Each spore has a single pyriform polar capsule. Spores measured about 23.3 ± 0.3 (20.4-27.1) µm long and 13.4 ± 0.4 (11.5-14.2) µm wide. The polar capsule was 11.7 ± 0.3 (9.2-12.5) µm long and 4.7 ± 0.3 (3.5-6.2) µm wide, containing a polar filament coiled perpendicular to the longitudinal axis of the spore body making eight turns. Occasionally, an oblong, irregular-shaped mass of protoplasm with a slightly oval nucleus (1.4 µm in diameter) and a small iodinophilous vacuole measured 0.85 ± 0.2 µm (0.73-1.2 µm) were observed in the spore. Due to the lack of the second polar capsule characterizing Myxobolus sp., the present parasite is placed within the genus Thelohanellus. Based on morphological differences (compared with other members of Thelohanellus Kudo, 1933) and the host specificity, this species is described as a new one of the genus Thelohanellus recorded for the first time in Egypt.

Developmental stages of Hepatozoon seurati (Laveran and Pettit 1911) comb. nov., a parasite of the corned viper Cerastes cerastes and the mosquito Culex pipiens from Egypt.

Developmental stages of Hepatozoon seurati (Laveran and Pettit 1911) comb. nov. are described from the tissues of the corned viper Cerastes cerastes, and from the vector Culex pipiens. The parasite described in the present study is firstly recorded as Haemogregarina seurati (Laveran and Pettit 1911) in the same host. After demonstration of the sporogonous development in the mosquito vector (C. pipiens) which showed all characteristics of the genus Hepatozoon (large oocysts containing many sporocysts producing numerous sporozoites), the parasite should be transferred into the genus Hepatozoon. The infected erythrocytes measured 20 ± 0.95 × 7.3 ± 0.85 µm; while uninfected cells measured 13.3 ± 1.04 × 7.5 ± 0.16 µm. Hypertrophy and faintly stained cytoplasm are mostly occurred in infected erythrocytes. Blood stages of the parasite were found exclusively in the erythrocytes in two forms: (1) small trophozoites (10.0 ± 0.52 × 3.0 ± 0.4 µm) and (2) long (mature) sausage-shaped (16.5 ± 1.5 × 3.5 ± 0.4 µm). Merogony occurred in the endothelial cells of the blood capillaries of lung, liver, and spleen. Mature meronts was 27.6 ± 0.7 × 17.5 ± 0.5 µm in diameter and contained 20-35 merozoites (averaged in 26). These merozoites measured 16.5 ± 1.5 × 3.5 ± 0.4 µm. Syzygy and gamogony occurred in the mosquito myxocoel till the 5th day post-infection (p.i.) while sporogony took place after 15 days p.i. On the third day p.i., a large spherical macrogamete of 29.0 ± 0.8 × 20.5 ± 0.6 µm containing a distinct nucleus in association with a single microgamete were observed. The microgamete was pyriform measured 8 ± 02 µm in length. It had a prominent nucleus and a long flagellum of at least 20.4 ± 1.3 µm in length. Fertilization occurred on the 3rd to the 4th days p.i. and the formed zygote developed into an oocyst in which repeated mitotic divisions with centripetal invaginations occurred producing sporoblasts. After sporulation, each sporoblast termed as sporocyst, and contained 18 banana-shaped sporozoites measured 14.0 ± 1.6 × 3.2 ± 0.6 µm. Experimental transmission was successful by intraperitoneal inoculation of the infective stages (sporozoites) to uninfected vipers and led to the appearance of blood stages after 5-6 weeks.

First record of Lecithochirium grandiporum (Digenea: Hemiuridae) infecting the lizard fish Saurida tumbil from the Red Sea.

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.

Morphology and small subunit ribosomal DNA sequence of Henneguya suprabranchiae (Myxozoa), a parasite of the catfish Clarias gariepinus (Clariidae) from the River Nile, Egypt.

Forty-three out of 120 (35.8%) Clarias garipenus fish were found to be naturally infected with Henneguya suprabanchiae. The infection appeared as clusters of ovoid to ellipsoidal plasmodia being embedded within the hyaline cartilage of the suprabranchial organ of the fish. Histological studies indicate tissue distortion at the sites of infection. The continuous growth of the plasmodium led to deformation of the filament structure as well as disorganization and displacement of the gill lamellae. Also, a severe atrophy occurred in the hyaline cartilage of the gills and also in the gill lamellae. Based on the structure and measurements of fresh spores by light microscopy, this parasite was identified as H. suprabranchiae. Spores are oval in shape, and they measure 13 (11-14) × 3 (2-5) µm length by width. It has two polar capsules inside, each measures 3 (2.5-5) × 1 (1.5-4) µm length by width. Each polar capsule has a spirally coiled (7-9 turns) polar filament. The ultrastructural analysis showed that the plasmodia were surrounded by single-unit membrane. The generative cells and the early developmental stages were arranged at the periphery of the plasmodia, while immature and mature spores were centrally arranged. The developmental stages characterizing sporogenesis, capsulogenisis, and valvogenesis of the present parasite were ultrastructurally studied. The small subunit 18 S rDNA (SSU rDNA) gene sequences from different isolates was sequenced and compared with the sequence of the same gene from the Henneguya sp. isolated from GenBank. The phylogenetic position of the present Henneguya sp. within the genus was determined using sequence analysis of all related taxa available in GenBank, and the phylogenetic tree derived from this study is elucidated and compared with the current taxonomy of the available myxosporeans. Comparison of the nucleotide sequences and divergence showed that the SSU rDNA gene of this Henneguya species revealed 92.2% sequence identity with Henneguya exilis (acc. no. AF021881) differing in 30 nucleotides with lower divergence value.