Light and electronic observations on Henneguya ghaffari (Myxosporea,Bivalvulida) infecting the gills and intestine of Nile perch Lates niloticus (Pisces: Teleostei) from Chad and Senegal

Henneguya ghaffari Ali, 1999, described for the first time in Egypt, has been found on gills and intestine of Nile perch Lates niloticus L. from Chad and Senegal (Africa). It formed plasmodia which induced lesions of infected tissues. In fresh state, the spore body was ovoid and its size was 11.07 +/- 0.7 (range 11 to 13) x 7.7 +/- 0.4 (range 7 to 8) microm. The length of the caudal appendages was 44.2 +/- 1.7 (42 to 48) microm. The polar capsules were pyriform, of equal size, with the polar filament showing 4 coils, and measuring 3.17 +/- 0.1 (range 3 to 4) x 2.2 +/- 0.1 (range 1 to 2) microm. The total length of the spore was 55.73 +/- 1.7 (range 53 to 61) microm. At ultrastructural level, our results confirm that in Henneguya species, the sporoplasm is binucleate and the pansporaoblast is disporous.     

Ultrastructural aspects of the myxosporean Henneguya astyanax n. sp. (Myxozoa: Myxobolidae), a parasite of the Amazonian teleost Astyanax keithi (Characidae)

This study reports light and electron microscopical aspects of a myxosporean found in the gills of the freshwater teleost Astyanax keithi Géry, Planquete & Le Bail, 1996 (family Characidae), collected from the estuarine region of the Amazon River, near Belém, Brazil. The prevalence of infection was 23%. In interlamellar spaces of the gills, ellipsoidal whitish cyst-like plasmodia structures were present, which contained spores. The spores had a spermatozoa-like appearance (47.8 +/- 0.71 microm in total length) with a fusiform body (15.2 +/- 0.77 pm in length, 5.7 +/- 0.71 microm in width and 4.2 +/- 0.31 microm in thickness), and each of the 2 valves presented a tapering tail (32.6 +/- 1.11 microm in length). The valves surrounded a binucleate sporoplasm cell and 2 polar capsules (5.0 +/- 0.13 microm in length, 1.5 +/- 0.07 microm in width) that contained 8 to 9 coils of the polar filament. In the sporoplasm, several unique sporoplasmosomes were visible. A synoptic table of spore measurements of known Brazilian Henneguya species is presented. The spores differed from those of previously described species. Based on spore morphology, it is concluded that this species belongs to the family Myxobolidae, genus Henneguya, and that it constitutes a new species: H. astyanax n. sp.     

Fine structure of the myxosporean,Henneguya curimata n. sp., parasite of the Amazonian fish,Curimata inormata (Teleostei,Curimatidae)

Henneguya curimata n. sp. (Myxozoa, Myxobolidae) is described from the kidney of the teleost Curimata inormata collected in an estuarine region of the Amazon River, near Belém. Brazil. This myxosporean produces large cysts (0.6-1.2 mm in diam.) that represent plasmodia containing all life cycle stages, including spores. The spore body is ellipsoidal (approximately 16.6 microm in length and approximately 6.2 microm in width), and each valve presents a tapering tail (approximately 19.1 microm in length). These valves surround the binucleate sporoplasm cell and two ellipsoidal polar capsules located side-by-side at the same level, measuring 6.5 x 1.2 microm each and containing 10-11 coils of the polar filament. On the basis of its host specificity and on data collected by light and electron microscopy, the organism, H. curimata n. sp. is distinguished as a new species. The taxonomic affinities and morphological comparisons with other similar species of the same genus are discussed.     

Strombidinopsis jeokjo n. sp. (ciliophora: choreotrichida) from the coastal waters off western Korea: morphology and small subunit ribosomal DNA gene sequence

The planktonic ciliate Strombidinopsis jeokjo n. sp. is described from Quantitative Protargol-Stained (QPS) preparations, and the sequence of the small subunit rDNA (SSU rDNA) from cultured cells is reported. This species is ovoid and bluntly tapered towards the posterior. The ranges (and mean +/- standard deviation, n = 31) of cell length, cell width, and oral diameter of the QPS-stained specimens were 100-190 microm (149 +/- 25), 60-105 microm (79 +/- 13), and 55-80 microm (64 +/- 5), respectively. Fifteen to seventeen external oral polykinetids had oral membranelle cilia 20-35 microm long. Twenty-six to twenty-eight somatic kineties were equally spaced around the cell body and extended from the oral to the posterior regions with 23-44 dikinetids per kinety. Both kinetosomes of each kinetid bore cilia 3-7 microm long. Strombidinopsis jeokjo had two ovoid macronuclei of 25-38 microm x 12-15 microm. When properly aligned, the sequence of the SSU rDNA of S. jeokjo (GenBank Accession No. AJ628250) was approximately 2% different from that of an unidentified Strombidinopsis species (GenBank Accession No. AF399132-AF399135), the closest species in the SSU rDNA sequence.     

Systemic infection of Kudoa lutjanus n. sp. (Myxozoa: Myxosporea) in red snapper Lutjanus erythropterus from Taiwan

A new species of Kudoa lutjanus n. sp. (Myxosporea) is described from the brain and internal organs of cultured red snapper Lutjanus erythropterus from Taiwan. The fish, 260 to 390 g in weight, exhibited anorexia and poor appetite and swam in the surface water during outbreaks. Cumulative mortality was about 1% during a period of 3 wk. The red snapper exhibited numerous creamy-white pseudocysts, 0.003 to 0.65 cm (n = 100) in diameter, in the eye, swim bladder, muscle and other internal organs, but especially in the brain. The number of pseudocysts per infected fish was not correlated with fish size or condition. Mature spores were quadrate in apical view and suboval in side view, measuring 8.2 +/- 0.59 microm in width and 7.3 +/- 0.53 microm in length. The 4 valves were equal in size, each with 1 polar capsule. Polar capsules were pyriform in shape, measuring 3.62 +/- 0.49 microm in length and 2.2 +/- 0.49 microm in width. Mild inflammatory responses or liquefaction of host tissue were associated with K. lutjanus n. sp. infection. The junction of shell valves appeared as overlapping, straight lines. The polar filament formed 2 to 3 coils. A general PCR (polymerase chain reaction) primer for Kudoa amplified the small subunit (SSU) rDNA sequences, and the amplified gene was sequenced. It was evident from the phylogenetic tree that the 3 strains tested, AOD93020M, AOD93028M and AOD93028B, were identical and belonged to the Kudoa SS rRNA subgroup. The evolutionary tree showed that these strains form a unique clade, at a distance from other Kudoa species and myxosporeans. The spore's morphological and ultrastructural characteristics, as well as the SS rDNA properties of the isolates, were also essentially identical and served to distinguish them from representative Kudoa. It is, therefore, proposed that the strains isolated from the diseased red snapper be assigned to a new species.     

Ultrastructure and small-subunit ribosomal DNA sequence of Henneguya lesteri n. sp. (Myxosporea), a parasite of sand whiting Sillago analis (Sillaginidae) from the coast of Queensland, Australia.

Henneguya lesteri n. sp. (Myxosporea) is described from sand whiting, Sillago analis, from the southern Queensland coast of Australia. H. lesteri displays a preference for the pseudobranchs and is typically positioned along the afferent blood vessels, displacing the adjoining lamellae and disrupting their normal array. The plasmodia appeared as whitish-hyaline, elliptical cysts (mean dimensions 230 x 410 microm) attached to the oral mucosa lining of the hyoid arch on the inner surface of the operculum. Infections of the gills were also found, in which the plasmodia were spherical, averaged 240 x 240 microm in size and were located on the inner hemibranch margin. The parasites lodged in the gill filament crypts and generated a mild hyperplastic response of the branchial epithelium. In histological sections, the plasmodium wall and adjoining ectoplasm appeared as a finely granulated, weakly eosinophilic layer. Ultrastructurally, this section of the host-parasite interface contained an intricate complex of pinocytotic channels. H. lesteri is polysporic, disporoblastic and pansporoblast forming. Sporogenesis is asynchronous, with the earliest developmental stages aligned predominantly along the plasmodium periphery, and maturing sporoblasts and spores toward the center. Ultrastructural details of sporoblast and spore development are in agreement with previously described myxosporeans. The mature spore is drop-shaped, length (mean) 9.1 microm, width 4.7 microm, thickness 2.5 pm, and comprises 2 polar capsules positioned closely together, a binucleated sporoplasm and a caudal process of 12.6 microm. The polar capsules are elongated, 3.2 x 1.6 microm, with 4 turns of the polar filament. Mean length of the everted filament is 23.2 pm. Few studies have analyzed the 18S gene of marine Myxosporea. In fact, H. lesteri is the first marine species of Henneguya to be characterized at the molecular level: we determined 1966 bp of the small-subunit (18S) rDNA. The results indicated that differences between this and the hitherto studied freshwater Henneguya species are greater than differences among the freshwater Henneguya species.     

An ultrastructural and histopathological study of Henneguya pellucida n. sp. (Myxosporea: Myxobolidae) infecting Piaractus mesopotamicus (Characidae) cultivated in Brazil

During a study of myxosporean parasites of cultivated freshwater fish, a new myxosporean species, Henneguya pellucida n. sp., was discovered. Of the 120 Piaractus mesopotamicus sampled, only 10 specimens (8.3%) were infected. Yellow, round plasmodia measuring 0.5-3 mm were found in the serous membrane of the visceral cavity and in the tunica externa of the swim bladder. Sporogenesis was asynchronous, with the earliest developmental stages aligned prevailingly along the endoplasmic periphery and mature spores in the central zone. The mature spores were pear shaped (total length: 33.3 +/- 1.5 microm, mean +/- SD; width: 4.1 +/- 0.4 microm; body length: 11.4 +/- 0.3 microm; caudal process length: 24.1 +/- 1.5 microm). The polar capsules were elongated (length: 4.0 +/- 0.4 microm; width: 1.6 +/- 0.2 microm). The development of the parasite in the swim bladder produced thickening of the tunica externa and a granulomatous reaction. There was no correlation between the prevalence of the parasite and the chemical and physical characteristics of the water. Infection was recorded only in juvenile specimens ranging in size from 9.5 to 20 cm.     

Histophatology and ultrastructure of Henneguya caudalongula sp. n. infecting Prochilodus lineatus (Pisces: Prochilodontidae) cultivated in the state of São Paulo, Brazil

The histological and ultrastructural characteristics of a new species of Henneguya and the host reactions to infection by this species are reported. Henneguya caudalongula sp. n. was found in the inter and intralamellar regions of the gills of Prochilodus lineatus (Valenciennes, 1836) cultivated at Center for the Research and Management of Continental Fishing Resources located in the municipality of Pirassununga, state of S?o Paulo, Brazil. The plasmodia were white and round or ellipsoidal and measured 0.2 to 1 mm in length. The development of the parasite was asynchronous and the mature spores were fusiform, with a total length 71 +/- 1.4 microm, body length of 16.6 +/- 0.54 microm and width 4.6 +/- 0.2 microm. The caudal process was 52.6 +/- 1.5 microm long. The polar capsules were elongate (length 6.1 +/- 0.19 microm, width 1.6 +/- 0.15 microm) and of equal size. The polar filament was coiled in 10-11 turns. The prevalence of the parasite was 48.3% and did not vary significantly with the season or host size.     

Six new species of microsporidia of the genus Amblyospora (Microspora: Amblyosporidae) from blood sucking mosquitoes (Diptera: Culicidae) from the west Siberia

Microsporidia of the genus Amblyospora parasiting the adipose body of mosquito larvae of the genus Aedes and Culex has been studied with both light and electron microscopy. Six new species of microsporidia are described based on ultrastructural characteristics of spores and sporogony stages. Amblyospora flavescens sp. n. Mature spores are egg-shaped. The spore wall with three layers, about 165 nm. Exospore is two-membranous. Subexospore is absent. Endospore is electron-translucent. Polaroplast consists of three parts: lamellar, large vesicular, lamellar. The anisofilar polar filament with 10--11 coils (3 1/2 + 2 1/2 + 4-5). Fixed spores are 6.3 +/- 0.1 x 4.24 +/- 0.1 microm. Amblyospora kolarovi sp. n. Mature spores are egg-shaped. The spore wall with three layers, about 265-315 nm. Exospore shapes tucks on the surface of spore. It is two-membranous. Subexospore is quagge, structural. Endospore is electron-translucent. Polaroplast consists of two parts: lamellar and large vesicular. The anisofilar polar filament with 11-13 coils (3 + 8-10). Fixed spores are 5.4-5.6 x 3.5-4.2 microm. Amblyospora orbiculata sp. n. Mature spores are widely egg-shaped. On a back pole there is a small concavity. The spore wall with three layers, about 155 nm. Exospore is shapes tucks on a surface of spore. It is two-membranous. Subexospore is absent. Endospore is electron-translucent. Polaroplast consists of three parts: lamellar, vesicular, lamellar. Polar filament is anisofilar, with 11 1/2 coils (4 1/2 + 1 + 6). Fixed spores are 6.3 +/- 0.1 x x 4.0 +/- 0.1 microm. Amblyospora rugosa sp. n. Mature spores are egg-shaped. On a back pole there is a small concavity. The spore wall with three layers, about 225 nm. Exospore is shapes tucks on a surface of spore. It is two-membranous. Subexospore is quaggy, structural. Endospore is electron-translucent. Polaroplast lamellate. Polar filament is anisofilar, with 17 1/2 coils (3 1/2 + 1 + 13). Fixed spores are 5.3 +/- 0.1 x 3.7 +/- 0.1 microm. Amblyospora undata sp. n. Mature spores are egg-shaped. The spore wall is three-layered, about 220 nm. Exospore is shapes tucks on a surface of spore. It is two-membranous. Subexospore is quaggy, structural. Endospore is electron-translucent. Polaroplast lamellate. The anisofilar polar filament with 8 coils (3 + 5). Fixed spores are 5.0 +/- 0.1 x 3.0 +/- 0.1 microm. Amblyospora urski sp. n. Mature spores have widely oval form. The back pole is concave. The spore wall with three layers, about 280 nm. Exospore is shapes tucks on a surface of spore. It is two-membranous. Subexospore is quaggy, structural. Endospore is electron-translucent. Polaroplast lamellate. Polar filament is anisofilar, with 6 coils (2 + 4). Fixed spores are 4.4 +/- 0.1 x 2.9 +/- 0.1 microm.     

Description of two new gill myxozoans from smallmouth (Micropterus dolomieu) and largemouth (Micropterus salmoides) bass

Two previously undescribed species of myxozoan parasites were observed in the gills of bass inhabiting the Potomac and James River basins. They are described using morphological characteristics and small-subunit (SSU) rDNA gene sequences. Both were taxonomically identified as new species of Myxobolus; Myxobolus branchiarum n. sp. was found exclusively in smallmouth bass, and Myxobolus micropterii n. sp. was found in largemouth and smallmouth bass. Small, spherical, white plasmodia of M. branchiarum from smallmouth bass were observed grossly in the gills; these plasmodia had an average length of 320.3 μm and width of 246.1 μm. The development of the plasmodia is intralamellar in the secondary lamellae of the gills. Mature spores were pyriform in shape with a length of 12.8 ± 1.4 (8.1-15.1) μm and width of 6.9 ± 1.1 (4.0-9.0) μm. Analysis of SSU rDNA identified M. branchiarum in a sister-group to 3 species of Henneguya , although morphologically caudal appendages were absent. Myxobolus micropterii observed in the gills of largemouth and smallmouth bass had larger, ovoid, cream-colored plasmodia with an average length of 568.1 μm and width of 148.1 μm. The cysts developed at the distal end of the gill filament within the primary lamellae. The mature spores were ovoid in shape with a length of 10.8 ± 0.7 (9.2-12.2) μm and width of 10.6 ± 0.6 (9.0-11.8) μm. SSU rDNA analysis placed M. micropterii in a sister group with Henneguya lobosa and Myxobolus oliveirai . The highest prevalence of M. branchiarum was observed in the gills of bass collected from the Cowpasture River (50.9%). Prevalence was 44.6% in bass from the Potomac River and only 4.3% in bass collected from the Shenandoah River. A seasonal study of M. branchiarum , which included both infected and uninfected smallmouth bass, determined that a significantly higher intensity was observed in the spring than in the summer (P < 0.001) or fall (P = 0.004). In an analysis excluding uninfected bass, a higher intensity was observed in the spring than in the summer (P = 0.001) or fall (P = 0.008). Prevalence and seasonal differences were not determined for M. micropterii .     

A new species of Myxozoa, Henneguya rondoni n. sp. (Myxozoa), from the peripheral nervous system of the Amazonian fish, Gymnorhamphichthys rondoni (Teleostei)

Henneguya rondoni n. sp. found in the peripheral lateral nerves located below the two lateral lines of the fish Gymnorhamphichthys rondoni (Teleostei, Rhamphichthyidae) from the Amazon river is described using light and electron microscopy. Spherical to ellipsoid cysts measuring up to 110 microm in length contained only immature and mature spores located in close contact with the myelin sheaths of the nervous fibres. Ellipsoidal spores measured 17.7 (16.9-18.1)-microm long, 3.6 (3.0-3.9)-microm wide, and 2.5 (2.2-2.8)-microm (n=25) thick. The spore body measuring 7.0 (6.8-7.3)-microm long was formed by two equal symmetric valves, each with an equal tapering tail 10.7 (10.3-11.0) microm in length. The tails were composed of an internal dense material surrounded by an external homogeneous sheath of hyaline substance. The valves surrounded two equal pyriform polar capsules measuring 2.5 (2.2-2.8)-microm long and 0.85 (0.79-0.88)-microm (n=25) wide and a binucleated sporoplasm cell containing globular sporoplasmosomes 0.38 (0.33-0.42) microm (n=25) in diam. with an internal eccentric dense structure with half-crescent section. Each polar capsule contains an anisofilar polar filament with 6-7 turns obliquely to the long axis. The matrix of the polar capsule was dense and the wall filled with a hyaline substance. The spores differed from those of previously described species. Based on the ultrastructural morphology of the spore and specificity to the host species, we propose a new species name H. rondoni n. sp.     

Parastrombidinopsis shimi n. gen., n. sp. (Ciliophora: Choreotrichia) from the coastal waters of Korea: morphology and small subunit ribosomal DNA sequence

The planktonic ciliate Parastrombidinopsis shimi n. gen., n. sp. is described from both living cells and quantitative protargol-stained (QPS) preparations and the sequence of the small subunit rDNA (SSU rDNA) is reported. This species is almost oval when the cells are alive; when stained, it is cylindrical for the upper two-fifths, half-bowl shaped for the middle two-fifths, and narrow rodshaped for the lower one-fifth. The ranges (and mean +/- standard deviation, n = 20) of cell length, cell width, and oral diameter of living cells were 112-221 microm (168 +/- 39), 88-176 microm (121 +/- 30), and 53-110 microm (80 +/- 14), respectively, while those of the QPS-stained specimens (n = 54) were 88-225 microm (162 +/- 29), 55-163 microm (102 +/- 19), and 53-98 microm (69 +/- 9), respectively. Thirty-six to 48 external oral polykinetids had cilia 25-40 microm long. However, unlike Strombidinopsis species sensu stricto, P. shimi has an external oral polykinetid zone that is an open circle. This species has two shorter polykinetids associated with the end of the oral polykinetid zone, deep in the oral cavity. Like Strombidinopsis species in the subclass Choreotrichia, 36-50 somatic kineties were equally spaced around the cell body and extended from the oral to the posterior regions with 68-105 dikinetids per kinety. Both kinetosomes of each kinetid bore cilia 3-10 microm long. Parastrombidinopsis shimi had 2 (1-4) ovoid macronuclei of 20-82 x 15-32 microm. When properly aligned, the sequence of the SSU rDNA of P. shimi (GenBank Accession No. AJ786648) was approximately 5% different from that of Strobilidium caudatum and 6% different from that of two Strombidinopsis species. Based both on morphology and gene sequence divergence, we establish this is as a new species in a new genus belonging to the family Strombidinopsidae.     

Light- and electron-microscope description of Kudoa paralichthys n. sp. (Myxozoa,Myxosporea) from the brain of cultured olive flounder Paralichthys olivaceus in Korea

A new Myxosporea, Kudoa paralichthys n. sp., is described from the brain of cultured olive flounder Paralichthys olivaceus in South Korea. Mature spores were quadrate in apical view, measuring 5.19 +/- 0.54 microm in length, 8.23 +/- 0.50 microm in width, and 6.87 +/- 0.45 microm in thickness. Four valves were equal in size, each with 1 polar capsule. Polar capsules were pyriform in shape, measuring 2.2 +/- 0.22 microm in length and 1.2 +/- 0.14 microm in breadth. The sporoplasm consisted of a larger outer cell completely surrounding a smaller inner one, and had cytoplasmic projections. The junctions of shell valves were L-shaped. The sutural planes converged at the anterior ends of the spores and were associated with 4 small apex prominences in the central meeting point of the spores.     

Testicular myxosporidiasis in anurans,with a description of Myxobolus fallax n. sp.

During studies of amphibian sperm cryopreservation, a new species of myxosporidean parasite (Myxozoa, Myxosporae) was observed in the testes of the Australian dwarf green tree frog Litoria fallax (Peters). Myxosporidiasis was found to have no affect on L. fallax body condition or sperm numbers. Myxobolus spores from L. fallax are morphologically distinct from Myxobolus hylae spores (infecting the sympatric Litoria aurea Lesson) and the three previously named (exotic to Australia) Myxobolus species found in anurans. Myxobolus fallax n. sp. is characterised by: pseudocyst white, spherical to ovoid, 141 x 74 to 438 x 337 microm in diameter (mature); plasmodium with spores loosely arranged within interior. Spores ovoid 13.4 +/- 0.5 (12.6-14.6) microm length, 9.5 +/- 0.4 (8.3-10.6) microm width, 6.8 +/- 0.4 (6.5-7.6) microm depth, 1.4 +/- 0.1 (1.3-1.6) length/width; polar capsules broadly pyriform and equal in size 4.2 +/- 0.3 (3.3-4.7) microm length, 2.4 +/- 0.2 (2.1-2.8) microm width; filament coils 7-8, wound tightly and perpendicular to the longitudinal axis of the capsule; polar filament 34 +/- 7.0 (18-50) microm length; intercapsular appendix and sutural ridge folds absent; and iodinophilous vacuole and mucous envelope lacking. In addition to this new species, data from archival samples of M. hylae are provided which show two morphologically distinct spore types. Both appeared rarely in the same pseudocysts and we cautiously retain the single species.     

Ultrastructural studies of Henneguya rhamdia n. sp. (Myxozoa) a parasite from the Amazon teleost fish, Rhamdia quelen (Pimelodidae)

Henneguya rhamdia n. sp. is described in the gill filaments of the teleost fish Rhamdia quelen, collected from the Peixe Boi River, State of Pará, Brazil. This myxosporean produced spherical to ellipsoidal plasmodia, up to 300 microm in diameter, which contained developmental stages, including spores. Several dense bodies up to 2 microm in diameter were observed among the spores. The spore body was ellipsoidal (13.1 microm in length, 5.2 microm in width, and 2.5 microm in thickness) and each of the two valves presented a tapering tail (36.9 microm in length). These valves surrounded the binucleated sporoplasm cell and two equal ellipsoidal polar capsules (4.7 x 1.1 microm), which contained 10-11 (rarely 12) polar filament coils. The sporoplasm contained sporoplasmosomes with a laterally eccentric dense structure with a half-crescent section. Based on the data obtained by electron microscopy and on the host specificity, the spores differed from previously described Henneguya species, mainly in their shape and size, number and arrangement of the polar filament coils, and sporoplasmosome morphology.     

Balanion masanensis n. sp. (ciliophora: prostomatea) from the coastal waters of Korea: morphology and small subunit ribosomal RNA gene sequence

The planktonic ciliate Balanion masanensis n. sp. is described from living cells, from cells prepared by quantitative protargol staining (QPS), scanning electron microscopy (SEM), and transmitted electron microscopy (TEM) preparations, and the sequence of its nuclear small subunit rDNA (SSU rDNA) is reported. This species is almost ovoid with a flattened anterior oral region when the cells are alive and stained. The flattened anterior region of a living cell often forms a dome with the perimeter receded in a groove, and this region is easily inflated or depressed. In SEM photos, a brosse of six to nine monokinetids (or possibly three to five dikinetids) was observed inside the circumoral dikinetids. In TEM photos, circumoral microtubular ribbons were observed below the oral cilia, which along with the oral flaps were 8-16 microm in length. The cytostome is a slight funnel-like central depression on the flattened anterior end. The morphological characteristics of this ciliate are identical to those of the genus Balanion (Order Prorodontida). The ranges (and mean+/-standard deviation) of cell length, cell width, and oral diameter of living cells (n=23-26) were 27-43 microm (35.2+/-4.6), 25-32 microm (28.6+/-2.3), and 25-30 microm (27.6+/-1.3), respectively, while those of the QPS-stained specimens (n=70) were 23-37 microm (30.6+/-3.5), 26-35 microm (30.7+/-2.2), and 26-33 microm (29.5+/-1.5), respectively. Forty-six to 55 somatic kineties (SKs) were equally spaced around the cell body and extended from the oral to near the posterior regions with 24-50 monokinetids per kinety. Each kinetid bore a cilium 2.8-7.2 microm long. A caudal cilium (ca 14 microm long) arose on the posterior end. The single ellipsoid macronucleus is 6.8-13.4 x 6.8-10.5 microm, accompanied by a single micronucleus (2.0-2.8 x 1.5-2.5 microm) visible only in QPS specimens. Because, the cell size, the number of SKs, and the number of kinetosomes per SK of this ciliate were much greater than those of Balanion comatum and Balanion planctonicum, the only two Balanion species so far reported, we have established B. masanensis n. sp. When properly aligned, the sequence of the SSU rDNA of B. masanensis n. sp. (GenBank Accession No. AM412525) was approximately 9% different from that of Coleps hirtus (Colepidae, Prorodontida) and 12% different from that of Prorodon teres (Prorodontidae, Prorodontida).     

Euplotespora binucleata n. gen., n. sp. (Protozoa: Microsporidia), a parasite infecting the hypotrichous ciliate Euplotes woodruffi, with observations on microsporidian infections in ciliophora

A new microsporidian species, Euplotespora binucleata n. gen., n. sp., from the brackish-water ciliate Euplotes woodruffi is described and defined on the basis of life history characteristics, light and electron microscopic features, and small subunit (SSU) ribosomal DNA (rDNA) sequencing. The life cycle of E. binucleata n. sp. probably has rather short merogonic and relatively long sporogonic phases. Some uninuclear meronts and sporonts, along with diplokaryotic sporoblasts and spores, were found in experimentally infected host cells. Such a peculiar life cycle has been induced experimentally in Euplotes eurystomus and constitutively microsporidian-free stocks of E. woodruffi. Spores of E. binucleata n. sp. are monomorphic, ovoid-cylindrical in shape, 3.44+/-0.17 x 1.65+/-0.22 microm in size, and characterized by a diplokaryotic condition and a large posterior vacuole. The polar tube is isofilar, 4.5-5.5 microm in length when ejected, and lacking a distinctive coiled region (half-coiled). The polaroplast is divided into two regions: the anterior part has a few lamellae close to the anchoring disc; and the posterior part is a rounded body (sack), about one-quarter of the spore length. Spores do not appear to cluster together as a group. Each spore is surrounded by a sporophorous membrane closely adjacent to the exospore layer. A phylogenetic analysis of SSU rDNA sequences by different methods placed E. binucleata n. sp. in a clade with representatives of the microsporidian genera Cystosporogenes and Vittaforma. Observations of microsporidia in several other ciliates are discussed in view of the microsporidian infection frequency in the phylum Ciliophora.     

石斑角形虫(黏体门, 角形虫科)的分子证据及其在不同宿主中的遗传变异

研究从中国东海的青石斑鱼 Epinephelus awoara Temminck & Schlegel 1842和褐带石斑鱼E. bruneus Bloch 1793的胆囊中检获了石斑角形虫 Ceratomyxa epinephela Wu, Wu et hua, 1993, 首次提供了其SSU rDNA和ITS1 rDNA序列, 并基于形态学和分子数据进行了重新描述。石斑角形虫成熟孢子的孢子长(4.8±0.5) μm (3.6—5.6 μm), 孢子厚(31.8±4.8) μm (23.3—37.5 μm); 孢子壳瓣光滑且等大, 由垂直的缝线连接; 极囊长(2.9±0.2) μm (2.4—3.7 μm), 极囊宽(2.6±0.2) μm (2.2—3.1 μm); 孢子夹角处稍微凹陷, 延伸至两端逐渐变平坦, 夹角为 (175.9±3.7)° (165.5°—179.7°)。基于SSU rDNA序列构建的系统发育树显示石斑角形虫与诺兰角形虫C. nolani Gunter & Adlard 2009, 卡特莫尔角形虫C. cutmorei Gunter & Adlard 2009和横山角形虫C. yokoyamai Gunter & Adlard 2009 有很近的亲缘关系, 且其宿主均为石斑鱼属物种。结果表明, 类群关系较近的宿主其寄生的同属黏孢子虫可能具有更近的系统发育关系。基于SSU rDNA和ITS1 rDNA的遗传分析显示, 石斑角形虫的4个分离株已发生了明显的遗传分化(形成了4个基因型), 形成了不同的种群, 但在不同宿主种类间并未形成特有的分化。     

Parvicapsula bicornis n. sp. and P. limandae n. sp. (Myxozoa, Parvicapsulidae) in Pleuronectidae (Teleostei, Heterosomata) from Denmark

Two species of Parvicapsula were found in the kidney tubules and the urinary bladder of 2 pleuronectid fish from the northern Oresund, Denmark. The coelozoic, spherical, disporic trophozoites of both species are 10 to 12 pm in diameter. The myxospores of both species are elongate, asymmetrical and slightly curved, and have spherical polar capsules. Parvicapsula bicornis n. sp. (6-8 x 5-6 microm, polar capsule 2.5 microm in diameter) occurs in Pleuronectes platessa. The polar capsules of P. bicornis are arranged symmetrically on either side of the longitudinal axis and its spores differ from other species of Parvicapsula in having two 2-3 microm long posterior processes of different length. Parvicapsula limandae n. sp. (8-11 x 4-5 pm, polar capsule 1.6 microm in diameter) is found in Limanda limanda. The polar capsules are arranged along the longitudinal axis. It differs from Parvicapsula unicornis Kabata, 1962, recorded from L. limanda, in the arrangement of the polar capsules and in the absence of a posterior horn-like projection. The phylogenetic relationship between P. bicornis n. sp., P. limandae n. sp. and other Parvicapsula spp. was examined with their partial small subunit rDNA (SSU rDNA) sequences. P. limandae n. sp. and P. asymmetrica appear to be closely related, while P. bicornis n. sp. and P. minibicornis are the most divergent members of the genus.