Polar Filament Coils Research Articles

Two new species of Unikaryon (Microsporidia) hyperparasitic in microphallid metacercariae (Digenea) from Florida intertidal crabs

The genus Unikaryon (Microsporidia) holds exclusively hyperparasites of Platyhelminthes. Four species of Unikaryon are presently known from trematodes infecting mollusks and fish, and one from a cestode infecting a fish. Here we report two species of Unikaryon from microphallid trematode metacercariae parasitizing the brachyuran crabs, Panopeus herbstii and Pachygrapsus transversus, collected from intertidal habitats in Florida. The first microsporidium, which we assign here to a new species, Unikaryon panopei sp. n., was isolated from Microphallus sp. encysted in Panopeus herbstii from Tampa Bay. The specific designation for the second Unikaryon sp. (Unikaryon sp. 2), which occurred in metacercaria of Diacetabulum sp. found in P. transversus from the Florida Keys, is pending due to the lack of SSrDNA sequence data. Light and electron microscopy demonstrates that both species display characteristics of the genus Unikaryon including the arrangement of spores in sets of two, large posterior vacuole, and eccentric position of the polar filament. Spores of Unikaryon panopei sp. n., unlike those of Unikaryon sp. 2, assemble in large membrane-bound masses containing hundreds of organisms, and display a larger number of polar filament coils – 7–8, compared to 4–5 in Unikaryon sp. 2 The SSUrDNA-inferred phylogenetic analysis places Unikaryon panopei in one clade with Unikaryon legeri, the only other molecularly characterized member of the genus, with 94% of SSUrDNA similarity. These findings increase the number of species parasitizing trematodes and broaden the host range of Unikaryon spp.

Tetra disseminated microsporidiosis: a novel disease in ornamental fish caused by Fusasporis stethaprioni n. gen. n. sp.

A novel microsporidial disease was documented in two ornamental fish species, black tetra Gymnocorymbus ternetzi Boulenger 1895 and cardinal tetra Paracheirodon axelrodi Schultz 1956. The non-xenoma-forming microsporidium occurred diffusely in most internal organs and the gill, thus referring to the condition as tetra disseminated microsporidiosis (TDM). The occurrence of TDM in black tetra was associated with chronic mortality in a domestic farmed population, while the case in cardinal tetra occurred in moribund fish while in quarantine at a public aquarium. Histology showed that coelomic visceral organs were frequently necrotic and severely disrupted by extensive infiltrates of macrophages. Infected macrophages were presumed responsible for the dissemination of spores throughout the body. Ultrastructural characteristics of the parasite developmental cycle included uninucleate meronts directly in the host cell cytoplasm. Sporonts were bi-nucleated as a result of karyokinesis and a parasite-produced sporophorous vesicle (SPV) became apparent at this stage. Cytokinesis resulted in two spores forming within each SPV. Spores were uniform in size, measuring about 3.9 ± 0.33 long by 2.0 ± 0.2μm wide. Ultrastructure demonstrated two spore types, one with 9-12 polar filament coils and a double-layered exospore and a second type with 4-7 polar filament coils and a homogenously electron-dense exospore, with differences perhaps related to parasite transmission mechanisms. The 16S rDNA sequences showed closest identity to the genus Glugea (≈ 92%), though the developmental cycle, specifically being a non-xenoma-forming species and having two spores forming within a SPV, did not fit within the genus. Based on combined phylogenetic and ultrastructural characteristics, a new genus (Fusasporis) is proposed, with F. stethaprioni n. gen. n. sp. as the type species.

A new Myxobolus (Cnidaria: Myxosporea) infecting the ornamental catfish Corydoras schwartzi from the Purus River in Brazil

A new microscopic cnidarian is described, infecting five of thirty (16.6%) specimens of Corydoras schwartzi caught in the Purus River, State of Amazonas, Brazil. Histological analysis showed that cyst development occurred in the serosa layer of the intestine. Mature myxospores are ovoid in body shape in frontal view, 22.4 ± 0.3 μm in total length and 16.3 ± 0.1 μm in width. Internally, two aubergine-shaped, elongate symmetrical polar capsules occupy more than half the length of the spore, 14.3 ± 0.2 μm in length and 6.5 ± 0.1 μm in width. Ultrastructural analysis provided evidence of five polar filament coils inside the polar capsule and binucleated sporoplasm containing a moderate number of sporoplasmosomes. The valvogenic cells abutting each other form a sutural ridge and frequently a thin layer of homogeneous material separates the cells. The outer surface of the myxospore valves is smooth, with no evidence of formation of ridges in the valves. Immature myxospores in various stages of development were observed. This study is the first report of a myxosporean parasitizing C. schwartzi and the first report of a myxosporean infection in the intestine of an ornamental fish from South America.

A new myxozoan species Henneguya unitaeniata sp. nov. (Cnidaria: Myxosporea) on gills of Hoplerythrinus unitaeniatus from Mato Grosso State, Brazil.

On the basis of morphological and molecular analyses, a new myxozoan parasite is described from the gills of the fish Hoplerythrinus unitaeniatus, collected in the municipality of Nova Xavantina, Mato Grosso State, Brazil. Plasmodia of Henneguya unitaeniata sp. nov. were oval and whitish and were found surrounded by collagen fibers forming plasmodia wall between gill filaments on the gill arch. The spores were ellipsoidal with two similar polar capsules. Morphometric analysis showed a total spore mean length of 23.8 ± 1.5 μm, spore body mean length of 14.5 ± 0.7 μm, caudal appendage mean length of 10.3 ± 1.4 μm, thickness mean length of 4.3 ± 0.3 μm, polar capsule mean length of 4.2 ± 0.5 μm, polar capsule mean width of 1.8 ± 0.3 μm, spore mean width of 4.8 ± 0.4 μm, and 4-5 polar filament coils. Phylogenetic analysis showed Henneguya unitaeniata sp. nov. as a basal species in a subclade formed by myxozoans that parasitize bryconid fishes.

Morphological and molecular characterization of the muscle-infecting myxosporean Myxobolus xinyangensis sp. nov. from Abbottina rivularis in China

During an environmental assessment on the Huang River in Xinyang City (Henan Province, China), a novel Myxobolus species (Myxozoa: Myxobolidae) was found infecting the trunk muscle of Chinese false gudgeon Abbottina rivularis Basilewsky, 1855 (Gobioninae, Cyprinidae). Plasmodia of the new myxozoan, nominated herein as Myxobolus xinyangensis sp. nov., are round and yellowish, symmetrically and bilaterally located dorsal to the openings of the 2 opercula, and measure about 4.5 mm in diameter. The mature myxospores are orbicular in frontal view and fusiform in sutural view, with slightly tapered anterior end and rounded posterior end, and measure 9.4 ± 0.5 (8.7-10.6) µm long, 8.6 ± 0.6 (7.3-9.5) µm wide and 6.4 ± 0.3 (5.8-7.1) µm thick (mean ± SD, range). The ratio of spore length to spore width is close to 1. Two slightly unequal pyriform polar capsules, with tapering anterior ends and rounded posterior ends, measure 5.6 ± 0.67 (4.3-6.8) µm long and 3.0 ± 0.3 (2.4-3.6) µm wide, present as a figure 8 in the anterior part of spores and tightly converge at the top end of spores. Polar filament coils show 4 to 5 turns and are situated perpendicularly to the longitudinal axis of the polar capsules. No intercapsular appendix or sutural folds at the posterior end of spores were observed. The obtained partial small subunit ribosomal DNA sequence did not match any available data in GenBank and showed the highest sequence identity (93%) with 2 cyprinid trunk muscle-infecting Myxobolus species, M. pseudodispar and M. klamathellus. Phylogenetic analysis clearly showed that M. xinyangensis sp. nov. clustered within a cyprinid trunk muscle-infecting Myxobolus subclade at the basal position, but as an independent branch which was a possible reflection of its distinct myxospore morphology. This is the first record of infection of Myxobolus species in the trunk muscle of Abbotina fish.

Morphological and molecular characterization of Chloromyxum argusi n. sp. (Myxosporea) infecting the urinary bladder of Scatophagus argus Linnaeus 1766 (Scatophagidae) from the southwest coast of India

The present paper describes a new species of Chloromyxum infecting the urinary bladder of the estuarine fish, Scatophagus argus, from the southwest coast of India. The parasite exhibited an overall prevalence of 41.93%; the prevalence is influenced by host size and seasons. Mature spores are subspherical, measure 9.40 ± 0.66 by 9.32 ± 0.87μm, and are characterized by the presence of sutural and extra-sutural ridges, binucleated sporoplasm, and a pair of caudal extensions. Four pyriform, unequal polar capsules with raised polar filament discharge pores and ribbon-like polar filaments are present. Polar filament coils numbered four to five in large polar capsules and three in small polar capsules. Pansporoblast is irregular with granulated cytoplasm and has fine villosites on its surface. Plasmodia are spherical/irregular with monosporic and polysporic forms. In molecular and phylogenetic analysis, the myxosporean stands out with a high bootstrap value and was positioned as a sister branch of Chloromyxum kurisi. In view of the morphologic, morphometric, and molecular differences with the existing species of Chloromyxum, and considering the differences in hosts and geographic locations, the present species is treated as new and the name Chloromyxum argusi n. sp. is proposed.

A New Species of ThelohanellusKudo, 1933 (Myxozoa: Bivalvulida) Infecting Skeletal Muscle of Blacktail Shiner, Cyprinella venusta Girard, 1856 (Cypriniformes: Cyprinidae) in the Chattahoochee River Basin, Georgia.

Thelohanellus magnacysta n. sp. (Bivalvulida: Myxobolidae) infects the skeletal muscle of blacktail shiner, Cyprinella venusta Girard, 1856 (Cypriniformes: Cyprinidae) in Bull Creek, Chattahoochee River Basin, eastern Georgia. Although numerous members of ThelohanellusKudo, 1933 have overlapping myxospore dimensions with the new species, it differs from all nominal congeners by polar filament coil number and polar capsule width as well as by lacking a mucous envelope, iodinophilic vacuole, and sutural markings. With the use of novel primers for Myxozoa, a phylogenetic analysis of the small subunit ribosomal DNA (SSU rDNA) suggests that the new species shares a recent common ancestor with a clade of cyprinid-infecting species of Myxobolus Bütschli, 1882 (Bivalvulida: Myxobolidae) and Thelohanellus. Consistent with other published research concerning the systematics of Thelohanellus, this result suggested that Thelohanellus and Myxobolus are polyphyletic and need revision. Histological sections of infected blacktail shiners confirmed that myxospores were only found within a plasmodium and only infected skeletal muscle and that plasmodia were encapsulated by a granuloma comprising varying degrees of acute granulomatous inflammation. The new species is the fourth of Thelohanellus reported from North America and the first reported from Cyprinella, as well as the first myxozoan described from the blacktail shiner.

Morphological and molecular confirmation of Myxobolus cerebralis myxospores infecting wild‑caught and cultured trout in North Carolina (SE USA).

We used microscopy and molecular biology to provide the first documentation of infections of Myxobolus cerebralis (Myxozoa: Myxobolidae), the etiological agent of whirling disease, in trout (Salmonidae) from North Carolina (USA) river basins. A total of 1085 rainbow trout Oncorhynchus mykiss, 696 brown trout Salmo trutta, and 319 brook trout Salvelinus fontinalis from 43 localities across 9 river basins were screened. Myxospores were observed microscopically in pepsin-trypsin digested heads of rainbow and brown trout from the Watauga River Basin. Those infections were confirmed using the prescribed nested polymerase chain reaction (PCR; 18S rDNA), which also detected infections in rainbow, brown, and brook trout from the French Broad River Basin and the Yadkin Pee-Dee River Basin. Myxospores were 9.0-10.0 µm (mean ± SD = 9.6 ± 0.4; N = 119) long, 8.0-10.0 µm (8.8 ± 0.6; 104) wide, and 6.0-7.5 µm (6.9 ± 0.5; 15) thick and had polar capsules 4.0-6.0 µm (5.0 ± 0.5; 104) long, 2.5-3.5 µm (3.1 ± 0.3; 104) wide, and with 5 or 6 polar filament coils. Myxospores from these hosts and rivers were morphologically indistinguishable and molecularly identical, indicating conspecificity, and the resulting 18S rDNA and ITS-1 sequences derived from these myxospores were 99.5-100% and 99.3-99.8% similar, respectively, to published GenBank sequences ascribed to M. cerebralis. This report comprises the first taxonomic circumscription and molecular confirmation of M. cerebralis in the southeastern USA south of Virginia.

Ceratomyxa azevedoi n. sp. (Myxozoa: Myxosporea) parasitizing the gallbladder of Lutjanus ehrenbergii in the Arabian Gulf.

A novel myxosporean species, Ceratomyxa azevedoi sp. n. is described from the gallbladder of the blackspot snapper, Lutjanus ehrenbergii (Peters), captured from the Arabian Gulf off Saudi Arabia. A total of 45 (26.8%) out of 168 fish specimens were found to be infected with Ceratomyxa azevedoi sp. n., the highest prevalence being observed in winter (42.9%, 18/42) and the lowest in autumn (11.9%, 5/42). Mature spores appeared as crescent to slightly elliptical-shaped, measuring 5-7 (6) μm in length and 12 (10-14) μm in thickness, with spherical polar capsules containing three polar filament coils. The morphometric and morphological comparison with similar species revealed the taxonomic novelty of this form, suggesting that it should be considered as new species. The phylogenetic analysis of C. azevedoi sp. n., based on partial SSU rDNA sequences, revealed close genetic relatedness to C. buri with 91.3% homogeneity and to C. hamour, with 90.1% homogeneity.

Morphological and phylogenetic analysis of a microsporidium (Nosema sp.) isolated from rice stem borer, Chilo suppressalis (Walker) (Lepidoptera: Pyralidae).

A new microsporidium was isolated from Chilo suppressalis (Walker) (Lepidoptera: Pyralidae), one of the most important rice pests in China. The morphology and molecular systematics of this novel microsporidium were described in this study. The spores were long oval and measured 3.17×1.64μm on fresh smears. Ultrastructure of the spores was characteristic for the genus Nosema: a diplokaryon, 10-12 polar filament coils of the same type, and posterior vacuole. Small subunit rRNA gene sequence data and phylogenetic analysis further confirmed that the microsporidian species from C. suppressalis belong to the true Nosema sub-group of the genus Nosema. Besides, the microsporidium Nosema sp. CS could cause systemic infection of Bombyx mori and infect silkworms through vertical transmission. Therefore, mulberry field pest control should be carefully monitored, and sanitation of mulberry leaves is essential to control the pebrine disease in sericulture.

Nosema neumanni n. sp. (Microsporidia, Nosematidae), a new microsporidian parasite of honeybees, Apis mellifera in Uganda

The microsporidium Nosema neumanni n. sp., a new parasite of the honeybee Apis mellifera is described based on its ultra-structural and molecular characteristics. Structures resembling microsporidian spores were found by microscopic examination of honeybees from Uganda. Molecular confirmation failed when PCR primers specific for Nosema apis and Nosema ceranae were used, but was successful with primers covering the whole family of Nosematidae. We performed transmission electron microscopy and found typical microsporidian spores which were smaller (length: 2.36±0.14μm and width: 1.78±0.06μm; n=6) and had fewer polar filament coils (10–12) when compared to those of known species infecting honeybees. The entire 16S SSU rRNA region was amplified, cloned and sequenced and was found to be unique with the highest resemblance (97% identity) to N. apis. The incidence of N. neumanni n. sp. in Ugandan honeybees was found to be much higher than of the two other Nosema species.

A report on two new myxozoan parasites infecting gills of fingerlings of Indian major carps cultured in nursery ponds in Punjab (India).

This paper presents the morphological characteristics of two new species belonging to the genus Myxobolus viz M. knobii n. sp. and M. majraiensis n. sp., parasites infecting gill lamellae and gill filaments of fingerlings of Cirrhinus mrigala (Ham.) and Catla catla (Ham.) respectively collected from nursery ponds located in the village Fagan Majra, District Fatehgarh Sahib, Punjab (India). A total of 90 fingerlings were examined (40 Catla catla and 50 Cirrhinus mrigala). Out of which, 32 C. mrigala and 19 C. catla fishes were found infected. The total prevalence rate was recorded as 56.66%. The age of the fish was recorded as 2-3months and length of the fish ranged 4-4.5cm. The plasmodia of M. knobii n. sp. were round to irregular, 0.6-1.0mm in diameter. Myxospores oval to spherical, pot-shaped in frontal view with a prominent knob at anterior end, measured 5.83×4.29µm in size. Polar capsules were equal, broadly pyriform, 1.95×1.70µm in size having 3-4 polar filament coils. The plasmodia of M. majraiensis n. sp. were round to oval, 0.8-1.5µm in diameter. Myxospores egg-shaped in frontal view also having prominent knob at the anterior end, measured 8.58×5.2µm in size. Polar capsules were equal, pyriform, 3.47×1.80µm in size having 5-6 polar filament coils. Gill plasmodium index showed heavy infection in both of the species. This is the first report of myxobolid infection in the fingerlings of Indian major carps in nursery ponds in Punjab (India).

Ultrastructural aspects and molecular phylogeny of Auerbachia maamouni n. sp. (Myxosporea: Bivalvulida) from the gallbladder of Gnathanodon speciosus Forsskål (Actinopterygii: Carangidae) in the Red Sea.

A new myxosporean parasite, Auerbachia maamouni n. sp., infecting the gallbladder of the golden trevally Gnathanodon speciosus Forsskål, is described, based on morphology, ultrastructure, and small subunit (SSU) rRNA gene sequencing. Of 50 fish collected from the Red Sea in Jeddah, Saudi Arabia, five were found heavily infected with mature myxospores floating free in the bile. Mature spores are pyriform to club-shaped with smooth valves, and contain a single polar capsule with an S-shaped polar filament, arranged in 13-16 polar filament coils, oriented longitudinally, with an irregular distribution on the polar capsule matrix. Spores measure 15.8 (14-17) μm in total length in lateral view, 7.9 (6-9) μm in width in apical view, with spore body length of 6.2±0.4 (5-7) µm. The ellipsoidal polar capsule has two adjusted lateral folds 7.6 (6-8) µm long and 2 (2-3) µm wide. The new species is distinguished from other species of the genus based on spore morphometry and molecular data. The phylogenetic tree constructed using Maximum Likelihood and Bayesian Inference analysis of SSU rDNA sequence data supported the phylogenetic position of A. maamouni n. sp. among the species of Auerbachia Meglitsch, 1968 sequenced to date. Analysis of the SSU rDNA sequence data also supported the assumption that Auerbachia is closely related to members of the genera Coccomyxa Léger & Hesse, 1907, Zschokkella Auerbach, 1910 and Myxidium Bütschli, 1882, whose members inhabit the gallbladder of marine teleost fishes.

New microsporidia, Glugea sardinellensis n sp (Microsporea, Glugeida) found in Sardinella aurita Valenciennes, 1847, collected off Tunisian coasts

A new microsporidia Glugea sardinellensis n. sp. found in the teleost fish Sardinella aurita Valenciennes collected from the Tunisian coasts. The parasite develops in a large xenomas measuring 1–16 mm in diameter and is generally visible with naked eye in the connective tissue around the pyloric caeca of the host. Xenoma were often rounded, but would be occasionally ovoid or irregular shape, generally creamy but rarely opaque, and filled with mature spores. The spores were unikaryotic pyriform measuring 5–5.5 (5.25±0.24) µm in length and 2.5–3 (2.75±0.24) µm in width. The posterior vacuole was large and occupied more than half of the spore. Ultrastructural study indicated that the mature spore has 13–14 coils of polar filament arranged in one layer, and a rough exospore. Intermediate stages were rare and randomly distributed in the xenoma. Merogonial and sporogonial stages were uni or binucleate. The plasma membrane surrounding the meront was irregular and indented. The mean prevalence was 18.3% and it varied according to season and locality. The distribution of prevalence according to fish size indicated that small fish were primarily affected. Phylogenetic analysis using the partial sequence of the SSU rDNA showed consistent association with species of the genusGlugea. The most closely related species was Glugea atherinae Berrebi, 1979 with 98.5% similarity.

The microsporidium Nosema disstriae (Thomson 1959): Fine structure and phylogenetic position within the N. bombycis clade

A microsporidium Nosema disstriae (Thomson) is a parasite of the forest tent caterpillar Malacasoma disstria (Lepidoptera: Lasiocampidae), a notable defoliator of deciduous trees in North America. The goal of this paper was to demonstrate the ultrastructure of N. disstriae and to determine the position of this microsporidium within the N. bombycis clade (NBC) using comparative morphology and multiple molecular phylogenetic markers: RPB1, LSU-, ITS- and SSU-rDNA. As a part of this goal, the revision of the described members of the NBC has been performed. The ultrastructure of proliferating stages and spores of N. disstriae were similar to previously described Nosema spp. parasitizing lepidopteran species. Meronts produced tubular-like structures on their surfaces and exhibited a tight association with host mitochondria. All stages were diplokaryotic and developed without interfacial envelopes. Disporoblastic sporogony produced typical Nosema-type spores with 9–12 polar filament coils. A vesicle with immature spores was once recognized on sections, concordant with the previous record of octosporous sporogony in the N. disstriae life cycle. Rarely, spores with thinner envelopes and large posterior vacuoles were seen in the midgut. Tracheae were most heavily infected. Midgut, surrounding muscles, haemocytes and fat body also contained microsporidia. SSUrRNA-inferred phylogenies were consistent with previously published articles and did not resolve the relation within the NBC clade. The RPB1-inferred trees and concatenated RPB1 and LSU-ITS-SSUrDNA-based trees demonstrated clustering of N. disstriae with N. antheraeae as early divergent species within the NBC.

Molecular and morphological characterisation of two species of the genus Ellipsomyxa Køie, 2003 (Ceratomyxidae) from the gall-bladder of Liza saliens (Risso) off Tunisian coasts of the Mediterranean.

During examination of some species of the family Mugilidae, two coelozoic myxozoans were observed in the gall-bladder of the leaping mullet, Liza saliens (Risso). Spore morphology allowed us to allocate them to the genus Ellipsomyxa Køie, 2003, one of which is described here as new. Ellipsomyxa kalthoumi n. sp. was observed forming globular pseudoplasmodia and free spores floating in the bile. Mature spores are ellipsoidal, measuring 13-21 × 10-15 (17.2 × 13.2) µm and possessing two equal spherical polar capsules, 5-6 (5.5) µm in diameter, opening subterminally in opposite directions, with nine polar filament coils. Morphological data and molecular analysis of the small subunit rDNA sequences helped identify this parasite as a new species of Elliposmyxa. The second species identified as E. mugilis (Sitjà-Bobadilla & Alvarez-Pellitero, 1993) has oval spores with rounded ends, measuring 10-11 × 7-9 (10.5 × 8.0) µm and possessing two polar subspherical capsules, 2.7-3.0 (2.8) µm in diameter, opening subterminally in opposite directions. Spore morphometry and molecular study of the small subunit (SSU) of the rRNA gene identified this species as E. mugilis described from the same host in the Western Mediterranean off Spain. Phylogenetic analysis revealed Elliposmyxa as a monophyletic clade and showed that E. mugilis, E. syngnathi Køie & Karlsbakk, 2009, E. adlardi Whipps & Font, 2012 and E. gobii Køie, 2003 group in a subclade containing the Tunisian isolate of E. mugilis whereas E. kalthoumi n. sp. appears in a second subclade together with four Australian species, E. maniliensis Heiniger & Adlard, 2014, E. apogoni Heiniger & Adlard, 2014, E. nigropunctatis Heiniger & Adlard, 2014 and E. arothroni Heiniger & Adlard, 2014.

Henneguya collaris sp. nov., (Myxosporidia), parasite of the Greenband Parrotfish Scarus collana Rüppell, 1835 (Actinopterygii, Scaridae) from the Red Sea, Egypt. A light and electron microscopic study.

The phylum Myxozoa comprises more than 2180 species, almost all of which are considered to be obligate parasites of aquatic fishes. In the present study, Henneguya collaris sp. nov. is the first described histozoic myxozoan species of the genus Henneguya infecting the kidney of the greenband parrotfish Scarus collana (Actinopterygii, Scaridae). One hundred and eighty specimens of fish were collected randomly during the period from September 2014 to October 2015 from boat landing sites and the market places at Hurghada City along the Red Sea in Egypt. Of these, 90 (50%) specimens were infected. Light microscopic examination showed that the infection was detected as mature spores with two polar capsules regularly arranged at the anterior pole of each spore and extruded polar filaments free in the kidney tissue. The spore body was oval in shape, measured 7.1 ± 0.2 (6.2-8.4) μm in length and 6.3 ± 0.2 (5.8-7.0) μm in width, with a bifurcated caudal process of equal length, reaching 6.3 ± 0.2 (5.8-7.0) μm in length. Polar capsules were 3.4 ± 0.2 (3.0-4.2) μm in length and 1.9 ± 0.2 (1.6-2.4) μm in width with 6-8 (10) turns of polar filaments. Ultrastructural analysis showed that the spore development was asynchronous. Sporogenesis, capsulogensis, valvogenesis, and spore maturation of the present parasite were also described. The present species was compared morphologically with the spore characteristics of the most similar species of Henneguya spp. recorded previously from different geographical areas taking into account the stage and dimensions of the spore body, tails, and polar filament coils, including their number and the most important characteristic features that distinguish them from the present species. Considering the data obtained, the material described herein represents a new species and the name Henneguya collaris sp. nov. is proposed.

Establishing a New Species Encephalitozoon pogonae for theMicrosporidian Parasite of Inland Bearded Dragon Pogona vitticeps Ahl 1927 (Reptilia, Squamata, Agamidae).

The microsporidium parasitizing Inland Bearded Dragons Pogona vitticeps, and developing primarily in macrophages within foci of granulomatous inflammation of different organs, is described as a new species Encephalitozoon pogonae. Establishing the new species was based on sequencing the ITS-SSUrDNA region of the ribosomal gene and consequent SSUrDNA-inferred phylogenetic analyses, as well as on comparison of pathogenesis, host specificity, and ultrastructure among Encephalitozoon species and isolates. The new species is closely related to E.lacertae and E.cuniculi. Analysis of the literature suggests that this microsporidium has been reported previously as an unidentified microsporidian species or isolate of E.cuniculi and may represent a common infection in bearded dragons. All stages of E.pogonae develop in parasitophorous vacuoles. Uninucleate spores on methanol-fixed smears measured 2.1×1.1μm, range 1.7-2.6×0.9-1.7μm; on ultrathin sections spores measured 0.8-1.1×1.8-2.2μm. Ultrastructural study revealed 3-6 polar filament coils, a mushroom-shaped polar disk, and a polar sac embracing half of the volume occupied by the lamellar polaroplast. In activated spores, polar filament everted eccentrically. The overall morphology and intracellular development of E.pogonae were similar to other Encepahalitozoon spp. We also review the existing data on microsporidia infecting reptiles.

Glugea jazanensis sp. nov. infecting Lutjanus bohar in the Red Sea: ultrastructure and phylogeny.

During a survey of the microsporean fauna of the two-spot red snapper Lutjanus bohar Forsskål, 1775, from the Red Sea off Jizan (Saudi Arabia), a species of Glugea Thélohan, 1891 was found that did not conform to any known species. The species is characterized by the presence of spherical xenomas (ca. 2-5 mm in diameter) in the host body cavity. Examination of the lifecycle stages and mature spores using light and transmission electron microscopy also revealed morphological characteristics typical of species of the genus Glugea. Spores were elongated-ovoid with a posterior vacuole surrounded by the polar filament coils. Mature spores were 4.5 (4.0-4.8) µm long and 2.5 (2.0-2.5) µm wide. The polar filament was isofilar with 28 to 30 coils, although in most cases 29 coils, organized in 3 rows. Phylogenetic study based on the partial sequence of the small subunit (SSU) rRNA gene clustered the new microsporidia within the clade grouping species of the genus Glugea. The comprehensive analysis of the parasite's ultrastructural characteristics, together with molecular data for the SSU rDNA gene, suggests that this parasite is a new species of the genus Glugea, for which the name Glugea jazanensis sp. nov. is proposed.

Ultrastructure and phylogeny of Glugea arabica n. sp. (Microsporidia), infecting the marine fish Epinephelus polyphekadion from the Red Sea

A new microsporidian species, Glugea arabica n. sp., is reported infecting the intestinal wall of the marine teleost Epinephelus polyphekadion (=microdon) collected from the Red Sea coast off Saudi Arabia, and described on the basis of microscopic and molecular procedures. Spherical blackish xenomas formed parasitophorous vacuoles completely packed with several parasitic developmental stages, including spores. The nuclei were monokaryotic in all developmental stages. Spores were ellipsoidal to pyriform and measured 6.3±0.3 (5.9–6.6) μm in length and 3.3±0.4 (2.9–3.7) μm in width. A lamellar polaroplast surrounded the uncoiled portion of the polar filament, which extended into the spore's posterior pole and formed 27–29 coils organized in three or four rows. The posterior vacuole, located at the spore's posterior pole, appeared surrounded by the polar filament coils and displayed an irregular matrix composed of light material, in which was located the posterosome. Molecular analysis of the rRNA genes, including the ITS region, was performed using maximum parsimony, neighbor-joining and maximum likelihood methodologies. The ultrastructural features observed, in combination with the molecular data analysed, suggests the parasite to be a new species of the genus Glugea.