A new genus Gadimyxa with three new species (Myxozoa, Parvicapsulidae) parasitic in marine fish (Gadidae) and the two-host life cycle of Gadimyxa atlantica n. sp

The myxozoans Gadimyxa atlantica n. sp. and G. sphaerica n. sp., and G. arctica n. sp. (Myxozoa, Parvicapsulidae), are described from Gadus morhua L. and Arctogadus glacialis (Peters) (Gadidae), respectively. They develop coelozoic in bisporic plasmodia in the urinary systems. Two morphological forms of spores were found in all 3 species, i.e., wide and (sub)spherical forms. Both spore types are bilaterally symmetrical along the suture line. The wide spores, semicircular in frontal view and elliptical in apical view, have 2 spherical polar capsules, which open in the sutural or median plane mid on the flat side of the spore. Mean widths of the wide spores of G. atlantica, G. sphaerica, and G. arctica are 7.5, 10.0, and 10.0 microm, respectively. The older, more thick-walled, (sub)spherical spores with binucleate sporoplasm are 8.0, 5.3, and 7.3 microm in mean width, respectively. The mean diameters of the polar capsules of (sub)spherical spores are 2.4, 1.7, and 2.2 microm, respectively. The (sub)spherical forms of Gadimyxa are most similar to Ortholinea within the Ortholineidae, but they differ in the development of the spores and in the arrangement of the polar capsules. The polychaetes Spirorbis spp. (Spirorbidae) act as invertebrate hosts of G. atlantica. The previously described actinospores of the tetractinomyxon type develop to myxospores in Gadus morhua within 8 wk. This is the second known myxozoan 2-host life cycle in the marine environment. Phylogenetic analyses based on partial small subunit rDNA sequences places Gadimyxa spp. among Parvicapsula spp. in the Parvicapsulidae.     

Myxobolus desaequalis n. sp. (Myxozoa,Myxosporea), parasite of the Amazonian freshwater fish,Apteronotus albifrons (Teleostei,Apteronotidae)

Myxobolus desaequalis n. sp. is described from the gill lamellae of the freshwater fish Apteronotus albifrons, collected in the Amazon River, near the city of Salvaterra, Brazil. Large spherical plasmodia filled with disporic pansporoblasts and spores were observed. Ellipsoidal to pyriform spores are 18.3 microm length x 11.2 microm width x 4.4 microm thickness. The anterior end of the spores contain two extremely unequal pyriform polar capsules measuring: (larger): 11.2 microm length, 4.9 microm width, and an isofilar polar filament with 11 to 12 turns obliquely to the longitudinal axis; (smaller): 4.6 microm length, 2.8 microm width, and an isofilar polar filament with 4 to 5 turns, obliquely to the longitudinal axis.     

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.     

Two unusual myxozoans,Kudoa quadricornis n. sp. (Multivalvulida) from the muscle of goldspotted trevally (Carangoides fulvoguttatus) and Kudoa permulticapsula n. sp. (Multivalvulida) from the muscle of Spanish mackerel (Scomberomorus commerson) from the Great Barrier Reef,Australia

Two unusual myxozoan parasites are described from the somatic muscle of 2 reef fishes from Australia's Great Barrier Reef. Kudoa quadricornis n. sp. from the somatic muscle of Carangoides fulvoguttatus is morphologically consistent with other Kudoa sp., having 4 polar capsules and 4 shell valves. Kudoa quadricornis n. sp. is unique in that it has a pyriform spore body with a greater length than width (7.82-9.95 and 5.94-8.66 microm, respectively) and distinct posterolateral projections. Spores of Kudoa permulticapsula n. sp. observed within pseudocysts of the somatic muscle tissue of Scomberomorus commerson are different from those of all other myxozoans. The ovoid spores (length, 4.69-6.65 microm; width, 8.42-9.92 microm; thickness, 6.36-8.33 microm) contain 13 polar capsules with an equal number of shell valves. Phylogenetic analysis using small subunit ribosomal DNA sequences of K. quadricornis n. sp. and K. permulticapsula n. sp. showed that these parasites cluster within a clade comprised of Kudoa species. This brings into question the division of parasites of the Multivalvulida into genera based solely on polar capsule numbers.     

Myxobolus goensis n. sp. (Myxozoa, Myxosporea, Myxobolidae), a parasite of the gills of Mugil cephalus (Osteichthyes, Mugilidae) from Goa, India

Two species of Myxobolus are reported from the gills of Mugil cephalus collected at Goa, India: M. goensis n. sp. and M. parvus Shulman, 1962. Myxobolus goensis n. sp. forms digitiform or rounded plasmodia between the gill rakers. Their spores are oval in frontal view, with tapered anterior extremity, and lemon-shaped in lateral view, measuring 9.7 (9.5-10.5) microm in length, 6.6 (6-7.5) microm in width, and 5.2 (5-6) microm in thickness. The polar capsules are pyriform and unequal in size. The larger ones are 5.3 (4.5-6) microm long and 2.4 (2-3) microm wide; the smaller ones are 2.4 (2-3) microm long and 1.8 (1.5-2) microm wide. The polar filament forms five turns aligned perpendicularly to the longitudinal axis of the larger polar capsules. Within the smaller polar capsules the polar filament is difficult to observe and, apparently, forms three coils. The spores are distinctly different from other Myxobolus species infecting M. cephalus and other Mugil spp. Furthermore, the present material is also different from 204 Myxobolus species presenting differently sized polar capsules, representing nearly all the known species with this characteristic. The fact that only the M. cephalus specimens were infected among a sample of 206 fish specimens, comprising 27 different species, strongly suggests that this parasite is specific to M. cephalus.     

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.     

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.     

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.     

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.     

Tetracapsula renicola n. sp. (Myxozoa : Saccosporidae); the PKX myxozoan--the cause of proliferative kidney disease of salmonid fishes

Proliferative kidney disease (PKD) of salmonid fishes is caused by the extrasporogonic stage of an enigmatic myxozoan, referred to as PKX. Sporogenesis occurs in the renal tubules, resulting in monosporous pseudoplasmodia. The spores are ovoid with indistinguishable valves and measure 12 microm in length and 7 microm in width. Two spherical polar capsules (2 microm diameter) with 4 coils occur at the anterior end of the spore. Prominent capsulogenic cell nuclei posterior to the polar capsules are evident in histological sections stained with hematoxylin and eosin. Regardless of the true nature of the valves (indistinguishable or absent), this myxozoan is morphologically distinct from all other described members of the phylum Myxozoa. Comparisons of small subunit rDNA sequences of PKX with other myxozoans demonstrated that it branches from all other members of the myxosporeans from fish examined thus far, including representatives of the phenotypically most closely related genera, Sphaerospora and Parvicapsula. Recent reports, based on rDNA comparisons, indicate that the alternate stage of PKX occurs in bryozoans, and that PKX clusters in a clade with Tetracapsula bryozoides. Our analyses and those of others, along with phenotypic observations, indicate that salmonids are the primary myxosporean hosts for PKX, that the cryptic spores of PKX in salmonids are the fully formed myxospores as they occur in the fish host, and that PKX represents distinct species that we previously place in the genus Tetracapsula in the family Saccosporidae. The latter 2 taxa were described based on stages from bryozoans, and the myxosporean stage in fish of the type species, T. bryozoides, has not been identified (if it exists). Thus, more complete resolution of the life cycle of both PKX and T. bryozoides, as well as more genetic data, are required to determine the precise relationship of these organisms.     

Ceratomyxa aegyptiaca n. sp. (Myxozoa: Myxosporea) from the gall-bladder of Solea aegyptiaca Chabanaud (Pleuronectiformes: Soleidae) in a Tunisian coastal lagoon

A new marine myxosporean species, Ceratomyxa aegyptiaca n. sp. is described from the gall-bladder of Solea aegyptiaca Chabanaud collected from the Ghar El Melh Lagoon in northeastern Tunisia. Mature spores are elongate and crescent-shaped, measuring 8-11?μm in length and 48-58?μm in width. The polar capsules are spherical, 3.2-4?μm in diameter and equal in size. Trophozoites are polysporous and float free in the bile or are attached on the epithelium of the gall-bladder. Morphological data and molecular analysis based on 18S rDNA sequences are provided. The 18S rDNA of C. aegyptiaca is readily distinguishable from that of other myxozoan species, as the genetically most similar myxozoan parasite, C. seriolae Yokoyama & Fukuda, 2001 (AB530265) collected from Seriola quinqueradiata Temminck & Schlegel in Japanese waters, shares with it only 67.5% identical nucleotides over a 1,680-bp long fragment of 18S rDNA.     

Cryptosporidium andersoni n. sp. (Apicomplexa: Cryptosporiidae) from cattle, Bos taurus

A new species of Cryptosporidium is described from the feces of domestic cattle, Bos taurus. Oocysts are structurally similar to those of Cryptosporidium muris described from mice but are larger than those of Cryptosporidium parvum. Oocysts of the new species are ellipsoidal, lack sporocysts, and measure 7.4 x 5.5 microm (range, 6.0-8.1 by 5.0-6.5 microm). The length to width ratio is 1.35 (range, 1.07-1.50). The colorless oocyst wall is < 1 microm thick, lacks a micropyle, and possesses a longitudinal suture at one pole. A polar granule is absent, whereas an oocyst residuum is present. Oocysts were passed fully sporulated and are not infectious to outbred, inbred immunocompetent or immunodeficient mice, chickens or goats. Recent molecular analyses of the rDNA 18S and ITS1 regions and heat-shock protein 70 (HSP-70) genes demonstrate this species to be distinct from C. muris infecting rodents. Based on transmission studies and molecular data, we consider the large form of Cryptosporidium infecting the abomasum of cattle to be a new species and have proposed the name Cryptosporidium andersoni n. sp. for this parasite.     

Myxobolus cuneus n. sp. (Myxosporea) infecting the connective tissue of Piaractus mesopotamicus (Pisces: Characidae) in Brazil: histopathology and ultrastructure

The characteristics of Myxobolus cuneus n. sp. and its relationship to the host Piaractus mesopotamicus are described based on light and electron microscopy and histological observations. Polysporic plasmodia measuring 20 microm to 2.1 mm in size were found in 63.3 % of the P. mesopotamicus examined. The parasite was found in the gall bladder, urinary bladder, gills, spleen, fins, head surface, liver and heart. Generative cells and disporoblastic pansporoblasts occurred along the periphery of the plasmodia, and mature spores were found in the internal region. The mature spores had a pear shaped body in frontal view, with a total length of 10.0 +/- 0.6 microm and a width of 5.1 +/- 0.3 microm (mean +/- SD). The spore wall was smooth with sutural folds. The polar capsules were elongated, were pear shaped, and equal in size (length 5.7 +/- 03 microm; width 1.7 +/- 0.2 microm), with the anterior ends close to each other. The polar filaments were tightly coiled in 8-9 turns perpendicular to the axis of the capsule. The plasmodia were always found in connective tissue (wall of the arterioles of the gill filaments, serous capsule of the gall bladder, middle layer and subepithelial connective tissue of the urinary bladder, connective tissue between the rays of the fins, subcutaneous tissue of the head surface and fibrous capsule spleen). The parasite caused important damage in the gills, where development occurred in the wall of gill filament arterioles; a mild macrophage infiltrate was also observed. In advanced developmental stages, the plasmodia caused deformation of the arteriole structure, with a reduction and, in some cases, obstruction of the lumen. The parasite was found throughout the period studied and its prevalence was unaffected by host size, season or water properties.     

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.     

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.     

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.     

Actinosporeans (Myxozoa) with four developing spores within a pansporocyst: Tetraspora discoidea n.g. n.sp. and Tetraspora rotundum n.sp.

Two species of marine actinosporeans with spores that develop in groups of four rather than eight within a pansporocyst are described. In other respects, including triradial symmetry, three polar capsules each enclosing a coiled polar filament, parasitic in invertebrates, they conform with other actinosporeans. Both new species were found in the coelom of tubificid oligochaetes collected from Moreton Bay, Queensland, Australia. Spores of Tetraspora discoidea n.g. n.sp. are disc-like, almost round in apical view and dorso-ventrally compressed in side view, whereas spores of Tetraspora rotundum n.sp. are spherical. The novel development of these two marine actinosporeans may signify other variations in the life-cycles of marine Myxozoa.     

A new parvicapsulid (Myxosporea) species in adult pink salmon, Oncorhynchus gorbuscha, from the Quinsam River, British Columbia, Canada

Myxospores consistent with species of Parvicapsula were observed in kidney of 15 of 95 (15.8%) adult pink salmon, Oncorhynchus gorbuscha, collected from the Quinsam River, British Columbia, Canada. The spores were elongate and curved with unequal valves, and 2 spherical-to-subspherical polar capsules within a highly refractile capsular region. The spores were unlike those of P. minibicornis found in nearby populations of Pacific salmon, Oncorhynchus spp. The spore dimensions were similar to those of Parvicapsula pseudobranchicola from Atlantic salmon, Salmo salar, in Norway, and the spores seemed similar to an undescribed Parvicapsula sp. from several Oncorhynchus spp. in Puget Sound, Washington. A sequence of 1,480 base pairs (bp) of the small subunit ribosomal RNA gene (SSU rDNA) of the parasite from pink salmon was most similar to, but distinct from, that of other Parvicapsula spp. The parasite is described as a new species, Parvicapsula kabatai n. sp. Polymerase chain reactions amplified a 158-bp sequence, unique to P. kabatai n. sp., from 22 of 93 (23.7%) adult pink salmon kidney samples, from 3 of 3 juvenile pink salmon collected in the ocean 125 km north of the Quinsam River, and from 2 of 5 archival coho salmon, Oncorhynchus kisutch, samples from Puget Sound. The parasite occurs within the lumen and epithelium of renal tubules and ducts, and within the renal interstitium. Concurrent infections with extrasporogonic stages of the myxosporean CKX, the microsporidian Loma salmonae, and a Myxidium sp. also were observed in the adult pink salmon.     

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.     

Phylogenetic position of Sphaerospora testicularis and Latyspora scomberomori n. gen. n. sp. (Myxozoa) within the marine urinary clade

An amendment of the family Sinuolineidae (Myxosporea) is proposed in order to include a newly described genus Latyspora n. gen. The type species Latyspora scomberomori n. gen. n. sp. is a coelozoic parasite in the kidney tubules of Scomberomorus guttatus. In addition to the morphological and molecular characterization of L. scomberomori n. gen. n. sp., we also present novel SSU rDNA data on Sphaerospora testicularis, a serious parasite of Dicentrarchus labrax. Performed phylogenetic analyses revealed that both species cluster within the marine urinary clade encompassing the representatives with a shared insertion within their V4 SSU rRNA region and grouping according to the shape of their spores' sutural line and their similar tissue tropism in the host. Sphaerospora testicularis is the closest relative to Parvicapsula minibicornis within the Parvicapsula subclade and L. scomberomori n. gen. n. sp. is the basal species of the Zschokkella subclade. The phylogenetic position of S. testicularis, outwith the basal Sphaerospora sensu stricto clade, and its morphology suggest it being a non-typical Sphaerospora. The sequence data provided on S. testicularis can help in future revisions of the strongly polyphyletic genus Sphaerospora. We recommend re-sequencing of several sphaerosporids as an essential step before such taxonomic changes are accomplished.