Ortholinea alata n. sp. (Myxosporea: Ortholineidae) in the northern butterfly fish Chaetodon rainfordi

Ortholinea alata n. sp. is described from the northern butterfly fish, Chaetodon rainfordi collected at Heron Island, Great Barrier Reef, Australia. Spherical, disporous trophozoites (10-15 micrometers) and spores were observed in the lumina of kidney tubules and collecting ducts. Spores are broadly triangular with two short, broad processes that extend dorsoventrad from the posterior end of each of the two spore valves. Valves are bisected by a suture in the plane of the polar capsules. Spores are 12.6 micrometers (length) x 9.6 micrometers (width) x 9.9 micrometers (length), and at the anterior end contain two spherical, divergent polar capsules measuring 4.6 (4.1-5.1) micrometers. Sporogenesis is similar to that of renal Sphaerospora spp.; the intraluminal trophozoites of O. alata n. sp. correspond to pseudoplasmodia described for Sphaerospora spp. and no large, multinucleated plasmodia are formed. No significant histopathological changes were observed in the kidneys of infected fish.     

Crepidula beklemishevi gen. et sp. n. and Dimeiospora palustris gen. et sp. n. (Microspora: Amblyosporidae)--new microsporidian genera and species from blood-sucking mosquitoes (Diptera: Culicidae) from the south of the western Siberia

Microsporidia parasitizing the adipose body of mosquito larvae of Anopheles beklemishevi and Aedes punctor has been studied. Two new genera of microsporidia are described based on lightmicroscopic and ultrastructural characteristics of spores and sporogony stages. The spore wall of Crepidula beklemishevi gen. n. et sp. n. is formed by two-membrane exospore, thick exospore, bilayer endospore and thin plasmolemma. Spores with single nucleus, polar filament anisofilar, with 6-7 coils (2+ 4-5), polaroplast consisting of three parts: macrochelicoidal, microhelicoidal and lamellar. Fixed spores 4.2 +/- 0.22 x 2 +/- 0.01 microns. The sporogony of Dimeiospora palustris gen. et. n. results in spore formation of two different types. Spores of the first type are oviform, with thick wall, single-nuclear, 6.1 x 4.9 microns. Spore wall with three layers, about 370 nm. Exospore electron-dense, subexospore moderately electrondense. Exospore and subexospore irregularly pleated on the almost spore surface and slightly thinner on anterior end only. Endospore electron-translucent. Polar filament anisofilar, with 9 coils (3 + 6). Polaroplas consists of three parts: lamellar, fine bubbled, and coarse bubbled. Spores of the second type broad-ovate, with apical pole narrower, distal pole concave, 4.6 x 3.7 microns. Spore wall with three layer, 355 nm. Exospore on the apical end irregularly pleated, consists of thin electrondense exospore, subexospore of variable electron density, endospore electron-translucent. Polar filament anisofilar, with 13 coils (3 + 10). Polaroplast has two parts: lamellar and vesicular.     

Light and electron microscopic observations of Leptotheca koreana n. sp. (Myxosporea) in the kidney of cultured rockfish Sebastes schlegeli.

The structure and sporogenesis of Leptotheca koreana n. sp. from cultured rockfish Sebastes schlegeli from South Korea were studied by light and transmission electron microscopy. Broadly oval spores and disporous pseudoplasmodia were observed in the lumen of renal tubules. Spores were 8.59 +/- 1.25 microm in length, 13.42 +/- 1.0 microm in width in sutural view and 8.13 +/- 0.52 pm in thickness in the plane perpendicular to the suture. The width of each valve was always smaller than spore length. Two spherical polar capsules were equal in size (3.86 +/- 0.45 microm in diameter) containing a polar filament with 6 to 7 turns, opening at the anterior end of the spore. Two uninucleate sporoplasms filled the spore cavity. The asynchronous division of secondary and tertiary cells and asynchronous development in spore formation of the present Leptotheca koreana resembled the disporous sphaerosporids. Cytoplasmic projections of pseudoplamodia were considered to be rhizoids, as they seem to strengthen the attachment to the epithelial cells of the renal tubules. The capsulogenic cells in early sporoblast had large amounts of rough endoplasmic reticulum but had a few Golgi apparatus.     

Henneguya schizodon n. sp. (Myxozoa, Myxobolidae), a parasite of the Amazonian teleost fish Schizodon fasciatus (Characiformes, Anostomidae)

A new histozoic species of myxosporean (Henneguya schizodon n. sp.) is described from the Amazon River teleost fish Schizodon fasciatus Spix & Agassiz, 1892 (Characiformes, Anostomidae). The plasmodia, which showed asynchronous development, were located in the kidney of the host. The spore body was ellipsoidal and was 13.1 (12-14) micron long by 3.3 (3-4) micron wide. The total length of the spore was 28.9 (27-30) micron, and each value had a caudal process measuring 16.3 (15-17) micron. The polar capsules were 5.4 (5-6) micron long by 1.3 (1-1.5) micron wide, and each had a polar filament with 8-10 coils. The characteristics of the species were compared with nearly all the species described so far, including all the species reported from South American fishes. This comparison allows to consider the materials as a new species, and the name Henneguya schizodon n. sp. is proposed.     

Gill sphaerosporosis in goldfish (Carassius auratus)

Infections caused by a Sphaerospora sp. resembling S. chinensis are reported for the first time in goldfish (Carassius auratus) from North America. The myxosporean was found in the respiratory epithelium of the gill of pond-reared fish. Spores from stained tissue sections were spherical with an equal mean length and width of 6.3 microns. Spore valves were thickened at the suture which lies in a plane perpendicular to two prominent pyriform polar capsules. The polar capsules were 4.0 x 2.8 microns in length and width. Both monosporous and disporous development within a surrounding "pseudoplasmodium" was detected. Infections caused moderate hyperplasia and occasional necrosis of the respiratory epithelial cells of the gill.     

Sphaerospora epinepheli n. sp. (Myxosporea: Sphaerosporidae) observed in grouper (Epinephelus malabaricus)

Sphaerospora epinepheli n. sp. is described from grouper, Epinephelus malabaricus, in cage-cultured and wild fish collected from both coastal lines of southern Thailand. Subspherical to spherical spores and mono- or disporous pseudoplasmodia were observed in the lumen of kidney tubules. Pseudoplasmodia were round to elongate, size range 15.6-22.9 microns (length) x 8.4-21.6 microns (width). Spores were 7.8-10.0 microns (length) x 12.3-14.5 microns (thickness), and 7.0-9.5 microns (width) with two spherical polar capsules of equal size measuring 2.9-4.4 microns in diameter and containing polar filaments with six or seven windings. Two uninucleate sporoplasms showed iodine vacuoles. Blood stages, similar to C-blood protozoans observed from freshwater fish in Europe, were found from peripheral blood smears of grouper. Ultrastructural studies of blood stages showed a similar structure to unidentified mobile protozoans from the blood of carp. Electron dense bodies were observed in the cytoplasm of the primary cell blood stages. Infected proximal-tubular epithelial cells showed highly vacuolated cytoplasm and pycnotic nuclei.     

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.     

Ultrastructure of Triangulamyxa amazonica n. gen. and n. sp. (Myxozoa, Myxosporea), a parasite of the Amazonian freshwater fish, Sphoeroides testudineus (Teleostei, Tetrodontidae)

Triangulamyxa amazonica n. gen. and n. sp. (Myxozoa, Ortholineidae), found in the lumen of the intestine of the freshwater fish Sphoeroides testudineus, is described. The fish were collected from the Amazon River near the city of Algodoal, State of the Pará, Brazil. Numerous irregular plasmodia containing different stages of sporogony, including spores, were observed. The plasmodia were lying free in the lumen or had slender pseudopodia-like cytoplasmic processes in contact with intestinal epithelial cells with microvilli projections. Spores, which are equilaterally triangular in valvar view with rounded pointed ends and ellipsoidal in transverse section, are 8.5 μm long, 7.6 μm wide, and 3.8 μm thick. The anterior end of the spores contains two equal drop-shaped polar capsules measuring 2.6 μm in length, each having an isofilar polar filament with 5–6 turns. The characteristics of the spore shape, the spore wall structure and its ridge organization, the plasmodial characteristics and the identity of the host suggest that the parasite is a new genus and species, which is herein designated T. amazonica.     

Myxidium volitans sp. nov., a parasite of the gallbladder of the fish, Dactylopterus volitans (Teleostei: Triglidae) from the Brazilian Atlantic coast--morphology and pathology

Myxidium volitans sp. nov. (Myxozoa: Myxidiidae) parasitizing the hypertrophied green-brownish gallbladder of the teleost Dactylopterus volitans, collected in the Atlantic coast near Niterói, Brazil was described based on ultrastructural studies. The spores were fusiform, sometimes slightly crescent-shaped on average 21.7 ± 0.3 μm (mean ± standard deviation) (n = 50) long and 5.6 ± 0.4 μm (n = 30) wide. The spore wall was thin and smooth, comprising two equally-sized valves joined by a hardly visible sutural ridge. Spores containing two pyriform polar capsules (PC) (5.0 ± 0.4 × 2.3 ± 0.3 μm) (n = 30) are situated in each extremity of the spore. The PC wall was composed of hyaline layer (0.20-0.29 μm thick) and by a thin external granular layer. Each PC contains a polar filament (PF) with irregular arrangements that was projected from its apical region to the bases of PC and coiled laterally from bases to the tip of PC. Some regular striations and S-like structures in the periphery of the PFs with four-five irregular sections were observed. Based on the spore morphology, ultrastructural differences and the specificity of the host we describe this parasite as a new myxosporidian, named M. volitans sp. nov.     

Myxobolus insignis sp. n. (Myxozoa, Myxosporea, Myxobolidae), a parasite of the Amazonian teleost fish Semaprochilodus insignis (Osteichthyes, Prochilodontidae)

A new myxosporean species is described from the fish Semaprochilodus insignis captured from the Amazon River, near Manaus. Myxobolus insignis sp. n. was located in the gills of the host forming plasmodia inside the secondary gill lamellae. The spores had a thick wall (1.5-2 microm) all around their body, and the valves were symmetrical and smooth. The spores were a little longer than wide, with rounded extremities, in frontal view, and oval in lateral view. They were 14.5 (14-15) microm long by 11.3 (11-12) microm wide and 7.8 (7-8) microm thick. Some spores showed the presence of a triangular thickening of the internal face of the wall near the posterior end of the polar capsules. This thickening could occur in one of the sides of the spore or in both sides. The polar capsules were large and equal in size surpassing the midlength of the spore. They were oval with the posterior extremity rounded, and converging anteriorly with tapered ends. They were 7.6 (7-8) microm long by 4.2 (3-5) microm wide, and the polar filament formed 6 coils slightly obliquely to the axis of the polar capsule. An intercapsular appendix was present. There was no mucous envelope or distinct iodinophilous vacuole.     

Description of a new species of Myxobolus (Myxozoa: myxobolidae) based on morphological and molecular data

Myxobolus ampullicapsulatus n. sp. was isolated from the gills of Carassius auratus auratus (L., 1758) in Chongqing, China. Myxospores were pyriform, measuring 16.5-19.5 microm long x 8.5-10.0 microm wide x 7.0 microm thick. Two equal polar capsules were ampullaceous, measuring 7.0-10.0 microm long x 2.5-4.0 microm wide, containing polar filaments coiled 9-10 turns. Spore length of this species exceeds that of the majority of other Myxobolus spp., and those overlapping in this dimension can be differentially diagnosed by other characters. Furthermore, the small subunit ribosomal DNA (SSU rDNA) of M. ampullicapsulatus n. sp. is unique among myxozoans sequenced to date. Phylogenetic analyses of the SSU rDNA gene sequence placed this species in a clade composed exclusively of gill parasites, most closely related to Myxobolus longisporus, which also infects the gills of cyprinid fishes in China.     

Sphaerospora ovophila N. Sp. and Myxobolus algonquinensis N. Sp. (Myxozoa, Myxosporea), Ovarian Parasites of Fish from Algonquin Park, Ontario, Canada

ABSTRACT. Sphaerospora ovophila n. sp. and Myxobolus algonquinensis n. sp., found in the ovary of the pumpkinseed ( Lepomis gibbosus ) and the golden shiner ( Noremigonus crysoleucas ) respectively from Algonquin Park, Ontario, are described using light and electron microscopy. Ovoid cysts of S. ovophila measured up to 500 pm in length. Monosporic pseudoplasmodia were ovoid or ellipsoid in shape and measured up to 12.5 pm in length. Spores were 7.2–8.4 pm long × 6.0–7.0 pm wide (in sutural plane) × 7.4–8.2 pm thick (perpendicular to sutural plane), with two subspherical polar capsules of equal size measuring 2.7–3.2 × 2.6–3.1 pm and each of which contained a polar filament with 6–7 coils. The spore had a straight sutural ridge which protruded slightly at the anterior end and contained two uninucleate sporoplasms. The spore valve had ornate folds on the posterior end. Cysts of M. algonquinensis ranged from ovoid to elongated ellipsoid in shape and measured up to 800 pm in length. Mature spores measured 13.G15.7 pm long × 10.1–12.1 pm wide × 5.0–6.9 pm thick. with two pyriform polar capsules of equal size measuring 5.1–5.5 pm × 2.5–2.9 pm, each of which contained a polar filament with 4–6 coils. The spores of M. algonquinensis had smooth valves, a straight sutural ridge and a distinct small intercapsular appendix.     

Ortholinea alata n. sp. (Myxosporea: Ortholineidae) in the Northern Butterfly Fish Chaetodon rainfordi

Ortholinea alata n. sp. is described from the northern butterfly fish, Chaetodon rainfordi collected at Heron Island, Great Barrier Reef, Australia. Spherical, disporous trophozoites (10–15 μ) and spores were observed in the lumina of kidney tubules and collecting ducts. Spores are broadly triangular with two short, broad processes that extend dorsoventrad from the posterior end of each of the two spore valves. Valves are bisected by a suture in the plane of the polar capsules. Spores are 12.6 μ (length) × 9.6 μ (width) × 9.9 μ (length), and at the anterior end contain two spherical, divergent polar capsules measuring 4.6 ( 4.1 –5.1) μ. Sporogenesis is similar to that of renal Sphaerospora spp.: the intraluminal trophozoites of O. alata n. sp. correspond to pseudoplasmodia described for Sphaerospora spp. and no large, multinucleate plasmodia are formed. No significant histopathological changes were observed in the kidneys of infected fish.     

Ultrastructural data on the spore of Myxobolus maculatus n. sp. (phylum Myxozoa), parasite from the Amazonian fish Metynnis maculatus (Teleostei)

Light and electron microscopy studies of a myxosporean, parasitic in the intertubular interstitial tissue of the kidney of the freshwater teleost fish Metynnis maculatus Kner, 1860 (Characidae) from the lower Amazon River (Brazil), are described. We observed polysporic histozoic plasmodia delimited by a double membrane and with several pinocytic channels and containing several life cycle stages, including mature spores. The spore body was of pyriform shape and was 21.0 microm long, 8.9 microm wide and 7.5 microm thick. Elongated-pyriform polar capsules were of equal size (12.7 x 3.2 microm) and contained a polar filament with 14 or 15 coils. The spore features fit those of the genus Myxobolus. Densification of the capsular primordium matrix, which increased in density from the inner core outwards, differentiating at the periphery into small microfilaments measuring 45 nm each, and tubuli arranged in aggregates and dispersed within the capsular matrix of the mature spores, are described. Based on the morphological differences and specificity of the host, we propose the creation of a new species named Myxobolus maculatus n. sp.     

Spore ornamentation of Haplosporidium pickfordi Barrow, 1961 (Haplosporidia), a parasite of freshwater snails in Michigan, USA

Spore ornamentation is increasingly recognized as a key character for species differentiation and genus assignment in the phylum Haplosporidia. Unfortunately, spore ornamentation is known for only a small number of described species so it is difficult to assign most species to genera with any confidence. Scanning and transmission electron microscopy were used to determine the presence and morphology of spore ornamentation of Haplosporidium pickfordi collected from the digestive gland of the snail Physella parkeri in Douglas Lake, Michigan. Spores possess filaments that are derived from the spore wall and originate from two separate areas at the posterior end of the spore. When spores are first isolated from host tissue, filaments are fused into a sheet that wraps around the spore, passing under the opercular lid. These filaments gradually unravel when spores are held in water and after about 14 d most filaments project freely from the posterior end of the spore. The number of filaments could not be determined with certainty, but appears to be approximately nine. Filaments are 100 nm in diam. and up to 50 microm in length. The presence of spore wall-derived filaments confirms the placement of the parasite in the genus Haplosporidium.     

Interrenal disease in bluegills (Lepomis macrochirus) caused by a new genus and species of myxozoan

A myxozoan species not matching with any described genus was encountered in a survey of fish parasites of freshwater fishes in New York. The parasite was observed in the kidney tubules of bluegill sunfish Lepomis macrochirus. A new genus is described to accommodate Acauda hoffmani n. gen., n. sp., which exhibits pyriform spores with longitudinal ridges and polar capsules perpendicular to the sutural plane. Spores measure 17.9-21.8 μm long and 6.9-11.0 μm wide, with spore valves each with 11-12 ridges. Two polar capsules measure 9.4-12.5 μm long by 2.9-4.0 μm wide and contain a filament coiled 10-15 times. Phylogenetic analysis places A. hoffmani n. gen., n. sp. as a sister to a Myxobilatus and a Hoferellus species. The clustering of these 3 similar genera in the larger 'freshwater' clade of myxozoans does not support their inclusion in the Sphaerosporidae but instead supports the distinct status of the Myxobilatidae Shulman 1953.     

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.     

鲫寄生碘泡虫属一新种

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