Synopsis of the species of Kudoa Meglitsch, 1947 (Myxozoa: Myxosporea: Multivalvulida)

A synopsis of the species of Kudoa Meglitsch, 1947 (Myxozoa, Myxosporea, Multivalvulida) is presented, including 95 nominal species. For each species the most relevant morphological and morphometric features are indicated in tabulated format. Included are data on the site of infection within the host, the type-host and type-locality, plus a full bibliography of the original records for these species. Molecular data (GenBank accession numbers) are also provided whenever possible.     

Synopsis of the species of Chloromyxum Mingazinni, 1890 (Myxozoa: Myxosporea: Chloromyxidae)

A synopsis of the species of Chloromyxum Mingazinni, 1890 (Myxozoa: Myxosporea: Chloromyxidae) is presented, including 140 nominal species. For each species the most relevant morphological and morphometric characteristics are indicated. Included are data on the site of infection within the host, the original host and the host locality, plus a full bibliography of the original records for these species. A diagrammatic illustration of a spore of each species is also provided.     

Supplemental diagnosis of Kudoa funduli (Myxozoa) parasitizing Fundulus heteroclitus (Cyprinodontidae) from coastal northeastern North America

The diagnosis of Kudoa funduli (Hahn, 1915) Meglitsch, 1948 (Myxozoa), is supplemented through study of new material collected from Fundulus heteroclitus (Cyprinodontidae) in coastal waters of Nova Scotia, Canada, and Connecticut. Plasmodia normally develop intracellularly in striated muscle of the flank and head, eventually rupturing and releasing spores. Spores disperse along adjacent epimysium, sometimes as far as the skin surface. Some plasmodia develop extracellularly within the bony cavities of vertebrae. Formalin-fixed spores viewed with a light microscope possess rounded edges, an inconspicuous apical region, thin sutural ridges, measure 6.6-7.4 microm wide, 4.3-5 microm thick, and 5.1-5.4 microm long, and have 4 equally sized polar capsules, 1.7-2.3 microm length by 1.4-1.7 microm width. Scanning electron microscopy revealed that spores are almost stellate, with inconspicuous uplifted tips, and that, within intracellular plasmodia, are embedded in an extensive honeycomb-like matrix. Prevalence of infection of K. funduli was 100% in host populations sampled in both Nova Scotia and Connecticut. Molecular sequence data of the 18S ribosomal DNA (737 base pairs) reveal that K. funduli is a valid species and a member of a clade that includes Kudoa dianae Dyková, Avila, and Fiala, 2002, Kudoa miniauriculata Whitaker, Kent, and Sakanari, 1996, and Kudoa paniformis Kabata and Whitaker, 1981.     

Relationships among members of the genus Myxobolus (Myxozoa: Bilvalvidae) based on small subunit ribosomal DNA sequences

Sequences representing approximately 1,700 base pairs of the 18S rRNA gene from 10 different species in the genus Myxobolus were found to group them into 3 clusters that showed little correlation with spore morphology and size or host specificity, criteria currently used for both higher and lower taxonomic placements in the Myxozoa. Of the phenotypic criteria examined, tissue tropism was most correlated with the rRNA groupings observed. Spores of similar size and shape (Myxobolus cerebralis vs. Myxobolus squamalis) were distantly related in some instances, whereas spores with divergent morphology and size were sometimes found to be closely related (M. cerebralis and Myxobolus insidiosus). These initial investigations into the phylogenetic relationships of putative members of the genus Myxobolus clearly indicate the potential limitations of groupings based on size and morphological properties of the spores and host species infected. We propose that 18S rRNA gene sequences, combined with information on tissue tropism, host species infected, and developmental cycles in the fish and alternate host (when and if known) be given greater consideration in taxonomic placements of myxosporeans.     

Two New Species of Myxozoa, Myxobolus inaequus sp. n. and Henneguya theca sp. n. from the Brain of a South American Knife Fish, Eigemannia virescens (V.)

Two new species of Myxozoa from the brain of the green knife fish Eigemannia virescens are described: Myxobolus inaequus sp. n. has an unusually large spore body and extremely unequal polar capsules, and Henneguya theca sp. n. has an attenuated spore encased in a sheath not previously described in other Myxozoa. Only spores of the two species were observed, and infections caused no obvious pathological changes in the brain.     

Two new species of Myxozoa, Myxobolus inaequus sp. n. and Henneguya theca sp. n. from the brain of a South American knife fish, Eigemannia virescens (V.)

Two new species of Myxozoa from the brain of the green knife fish Eigemannia virescens are described: Myxobolus inaequus sp. n. has an unusually large spore body and extremely unequal polar capsules, and Henneguya theca sp. n. has an attenuated spore encased in a sheath not previously described in other Myxozoa . Only spores of the two species were observed, and infections caused no obvious pathological changes in the brain.     

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.     

Replacement of the preoccupied name Davisia Laird 1953 and description of a new myxozoan species (Myxosporea: Sinuolineidae) from Sebastiscus marmoratus (Cuvier, 1829) in the East China Sea

The myxozoan genus Davisia Laird 1953 is preoccupied by Davisia Del Guercio 1909 (Insecta: Hemiptera). Here, Myxodavisia nomen novum is proposed to replace the preoccupied name, and a new species is described. Myxodavisia sebastisca n. sp. was found in the urinary bladder of Sebastiscus marmoratus, collected from coastal waters off Xiamen in the East China Sea. The parasite is characterized by a disporous trophozoite; spherical to subspherical spore, 13.1 +/- 0.3 (12.7-13.6) by 12.3 +/- 0.9 (10.9-13.5) microm in size; curved sutural line; 2 shell valves each with a long lateral appendage 119.4-335.2 microm in length; and 2 spherical or subspherical polar capsules, equal in size, 4.6 +/- 0.6 (3.2-4.6) microm in diameter. Traditionally, Myxodavisia is distinguished from Ceratomyxa, Sinuolinea, and Sphaerospora spp. by having spores that possess a distinct central chamber and lateral appendages. A review of the literature reveals that the presence or absence of a clear septum between these spore components is open to interpretation. Indeed, in immature spores of M. sebastisca n. sp., there was an indication of a demarcated appendage, but in some mature spores, no clear separation was apparent. Our findings suggest that future revision of this genus is warranted, particularly once DNA sequence data become available.     

Studies on Myxosoma cartilaginis n. sp. (Protozoa: Myxosporidea) of Centrarchid Fish and a Synopsis of the Myxosoma of North American Freshwater Fishes

SYNOPSIS. Myxosoma cartilaginis n. sp. is described from the cartilage of Lepomis macrochirus (bluegill), L. cyanellus (green sunfish) and Micropterus salmoides (largemouth black bass). The development of the parasite is described from naturally infected fish which were held in spore-free water after infection. The sporoplasm invades cartilage, and becomes a multi-nucleate trophozoite which forms pansporoblasts, each of which produces 2 to 4 spores. The first spores appear in 7 weeks.
The histopathology in the above fish consists at first of little cellular reaction, but after 4 to 5 months epithelioid granulomas appear around some of the spore masses. Cartilage liquefaction is present around the parasites for at least 5 weeks. Eosinophilic globules are present in cartilage cells adjacent to the lesions. Diffuse infiltration of the spores from the lesions is described.
Of 24 chemicals tested for polar filament extrusion, potassium hydroxide gave the best results.
An illustrated synopsis of the Myxosoma of North American fishes is given. Included is some additional information and illustrations of M. hoffmani Meglitsch, 1963. Also included is a table showing the hosts, site of infection, geographic location, spore and polar capsule sizes.     

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.     

Spore production and mycorrhizal development in various tropical crop hosts infected with Glomus clarum

Plant growth, mycorrhizal development and vesicular arbuscular spore production were examined in five tropical crop host species inoculated with Glomus clarum and grown in a glasshouse. In one of the two experiments, sequential harvests of maize, sorghum and chickpea were made in order to study spore production in relation to plant growth and mycorrhizal development. Spore numbers in each of these hosts increased at a fairly constant rate until maximum plant dry weight, when spore production ceased. Sorghum and maize produced considerably more spores than chickpea, with spore numbers being closely correlated with mycorrhizal root length. In the second experiment, Glomus clarum was cultured on each of maize, millet, sorghum, groundnut and chickpea for three consecutive generations before cross-inoculation of the spores from each host onto all five hosts. Sporulation with respect to host size was generally greatest when the inoculum used to infect a host had been produced on that host. The growth-promoting effects of the fungus were not influenced by the source of the inoculum. More spores were produced on the cereals than the legumes. Differences in spore numbers amongst hosts and plant generations were apparently influenced mainly by infected root length and by the growth period.     

A new myxozoan parasite from the Amazonian fish Metynnis argenteus (Teleostei, Characidae): light and electron microscope observations

Myxobolus metynnis n. sp. (Phylum Myxozoa) is described in the connective subcutaneous tissues of the orbicular region of the fish, Metynnis argenteus (Characidae), collected in the lower Amazon River, near the city of Peixe Boi, Pará State, Brazil. Polysporic, histozoic plasmodia were delimited by a double membrane with numerous microvilli on the peripheral cytoplasm. Several life-cycle stages, including mature spores, were observed. An envelope formed by numerous fine and anastomosed microfibrils was observed at the spore surface. The spore body presented an ellipsoidal shape and was about 13.1 microm long, 7.8 microm wide, and 3.9 microm thick. Elongated-pyriform polar capsules were of equal size, measuring 5.2 microm in length, 3.2 microm in width, and possessing a polar filament with 8-9 turns around the longitudinal axis. The binucleated sporoplasm contained a vacuole and numerous sporoplasmosomes. These were circular in cross-section, showing an adherent eccentric, dense structure, with a half-crescent section. Based on the morphological differences and host specificity, we propose that the parasite is a new species named Myxobolus metynnis n. sp.     

Synopsis of the species of Ceratomyxa Thélohan, 1892 (Myxozoa: Myxosporea: Ceratomyxidae)

A synopsis of the species of Ceratomyxa Thélohan, 1892 (Myxozoa: Myxosporea: Ceratomyxidae), including a total of 147 species, is presented. For each species the relevant morphological and morphometric data are indicated, as well as the site of infection within the host and the original hosts and locality. A diagrammatic illustration of the spores is also provided.     

Description of Myxobolus gayerae sp. n. and re-description of M. leuciscini infecting European chub from the Hungarian stretch of the river Danube

Myxobolus gayerae sp. n. and M. leuciscini González-Lanza & Alvarez-Pellitero, 1985 (Myxozoa: Myxobolidae) have been described and re-described from European chub Leuciscus cephalus L. from the Hungarian stretch of the river Danube. The ellipsoidal plasmodia of M. gayerae sp. n. were found in the mucosa of the intestinal wall, whereas the large, elongated plasmodia of M. leuciscini infected the afferent arteries of the gill filaments. The spores of M. gayerae sp. n. are relatively large, slightly oval and almost rectangular in shape. On the basis of spore morphology and 18S rDNA sequences, the most similar species was M. cycloides Gurley, 1893, but the 2 species differed in host and tissue tropism as well as in the size of the spores. The spores of M. leuciscini from L. cephalus, having no intercapsular appendix or occasionally a very small one, showed a high morphological similarity to spores collected from L. cephalus cabeda, Chondrostoma polylepis and Rutilus arcasi in Spain and described as M. leuciscini González-Lanza & Alvarez-Pellitero, 1985.     

Germination and infectivity of ectomycorrhizal fungal spores in relation to their ecological traits during primary succession

The spores of ectomycorrhizal fungi (EMF) play critical roles in the population and community development of EMF. Here, the germination and infectivity of EMF spores are examined with reference to the ecological traits of the EMF species. Spores were collected from 12 EMF species, whose successional patterns have been studied in the volcanic desert on Mount Fuji, Japan. Spore germination experiments were conducted with host plants (Salix reinii), with nonhost plants (Polygonum cuspidatum), and without plants. The mycorrhizal formation ability of spores was also examined in seven EMF using spore inoculation experiments. To determine the effects of the spore preservation period, both experiments were repeated up to 1 yr after spore collection. Spore germination was very low in the absence of host plants. In the presence of hosts, even 30 d after spore collection, spore germination was significantly enhanced in all pioneer EMF (c. 20%) but less so in late-stage EMF (< 5%), except in Hebeloma species. Mycorrhizal formation from spores was also greater in pioneer EMF but was significantly reduced by 1 yr of spore preservation. High spore germination and infectivity of pioneer EMF should enable these species to colonize disturbed and isolated areas in accordance with their ecological traits.     

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.     

Molecular and Morphometric Characteristics of Ceratomyxa hamour n. sp. (Myxosporea: Bivalvulida) Infecting the Gallbladder of the Orange‐spotted Grouper Epinephelus coioides from the Arabian Gulf,Saudi Arabia

Ceratomyxa hamour n. sp. was found to infect the gallbladder of the orange‐spotted grouper, Epinephelus coioides located off the Saudi Arabian coast of the Arabian Gulf. The infection was reported as a free‐floating spore in the bile, and pseudoplasmodia were not observed. Mature spores were crescent‐shaped and measured on average 7 μm in length and 16 μm in thickness. The polar capsule, meanwhile, had length to width measurements of 4 μm and 3 μm on average. A periodical survey was conducted throughout a sampling period between December 2012 and December 2013, with the results showing that the parasite was present throughout the year with a mean prevalence of 32.6%. The objective of this study was to characterize this new species based on its morphological and molecular differences from previously described species. Molecular analysis based on the partial sequence of the SSU rDNA gene, showed the highest similarity (97.8%) to Ceratomyxa buri, reported in the cultured yellow tail Seriola quinqueradiata in Japan. Indeed, C. buri and the new species described here formed an individual cluster with a high degree of bootstrap support. This is the first reported species of genus Ceratomyxa from the Arabian Gulf fishes off Saudi Arabia.     

Application of nested-PCR technique to resting spores from the Entomophthora muscae species complex: implications for analyses of host-pathogen population interactions

We developed new Entomophthora-specific primers for nested-PCR of the ITS II region to be used on in vivo material and combined it with RFLP. Resting spores from Scathophaga stercoraria (3 specimens), Delia radicum (9 specimens), Botanophila fugax (1 specimen), and two syrphid host species, Platycheirus peltatus and Melanostoma mellinum (one specimen of each) were characterized genetically after analysis of RFLP-profiles of the PCR-products. The genetic characterization of the resting spore isolates was compared with twenty isolates of known primary conidial morphology (in vitro and in vivo) from the E. muscae species complex. The analysis allowed for the first time a separation of resting spore isolates into the species level, which is not possible only using morphological characters (diameter). Isolates originating from different specimens of the same host taxa appeared to be strongly clonal even they were sampled at different localities in different years. Isolates morphologically belonging to E. muscae s. str. (e.g., including E. scatophagae) could be separated genetically further into sub-groups entirely depending on the host taxa; each fungal genotype, either present at the conidial stage or at the resting spore stage, is correlated with one host species. Furthermore, E. muscae s. str. originating from D. radicum proved to be much more closely related to E. scatophagae than to E. muscae s. str. originating from M. domestica. None of the resting spore isolates could be assigned to E. schizophorae. The nested-PCR approach accompanied by RFLP proved its usefulness for identification of resting spores and for more detailed studies clarifying host-pathogen specificity and interactions. It seems that different members of the E. muscae species complex are able to complete their life cycle in only one host species and, further, that each pathogen-host system is independent.     

Systematic implications of flavonoid pigments in the fern genus hemionitis (adiantiaceae)

The closely related fern generaHemionitis L. andGymnopteris Bernhardi are separated primarily on differences in leaf architecture and venation. Studies indicate that these characters are highly variable and unreliably diagnostic. Further, the type species of the two genera readily hybridize with each other. Spore morphology, as exhibited by SEM, does not support the traditional alignment of the species in these two genera: some species ofHemionitis andGymnopteris have the same rugose to papillate spores, while other species from both genera possess crested spores. The flavonoid chemistry of these taxa coincides with spore type, i.e., taxa from both genera which possess crested spores produce kaempferol and quercetin 3-0-glycosides, while species with tuberculate spores produce only quercetin 3,4′-0-glycosides. The spore and chemical data suggest a realignment of these taxa within a single genus, which would avoid the rather tenuous dependence on a single vegetative character for generic distinctions.