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2. Ceratomyxa drepanopsettae in the gallbladder of Atlantic halibut, Hippoglossus hippoglossus, from the northwest Atlantic Ocean
- Creator:
- Morrison, Carol M., Martell, D. John, Leggiadro, Cynthia, and O´Neil, David
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- Atlantic halibut, Hippoglossus hippoglossus, Myxosporea, Ceratomyxa drepanopsettae, trophozoites, sporoblast, sporogenesis, and spore
- Language:
- English
- Description:
- Trophozoites of Ceratomyxa drepanopsettae Averintsev, 1907 (Myxosporea: Ceratomyxidae) containing prominent refractile granules were found in the gallbladders of all but one of eight halibut, the exception being a single juvenile. They ranged in shape and size from globular forms 5-10 pm in diameter, to rounded structures with pseudopodia and one or more processes that were up to 500 pm in length and packed with refractile granules. Some trophozoites were free in the bile, while others were attached to the epithelium of the gallbladder wall by pseudopodia which extended between the microvilli. Many free trophozoites were attached to each other by septate junctions between their pseudopodia. There were small cylindrical papillae on the surface of the trophozoites, and the rounded portions contained two vegetative nuclei, generative cells (some attached by junctions) and, in many cases, feeding vacuoles. During sporogony, a binucleate sporoplasmic cell and the capsulogenic cells of some sporoblasts were engulfed by valvogenic cells before they began to differentiate; whereas other sporoblasts consisted of six cells attached to each other, two being capsulogenic cells containing external tubes, two sporoplasmic cells and two valvogenic cells. There was a septate junction around the opening of the rounded polar capsule of the spore, between the capsulogenic and valvogenic cell. Sporoplasmosomes appeared to form in smooth membraned vesicles, possibly part of the Golgi apparatus. Spores had a thin, delicate membrane, and elongate shell-valves, most of which were asymmetric, and bent or folded. A sporo-plasm extended on either side of the distinct, straight suture line, but did not penetrate into the valves.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
3. Infections of Unicauda clavicauda (Kudo, 1934) (Myxozoa) in the skin of Notropis hudsonius (Cyprinidae) from Montana, with a synopsis of the genus Unicauda Davis, 1944
- Creator:
- Cone, David K. and Melendy, Jason S.
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- Myxosporea, Unicauda clavicauda, and Notropis hudsonius
- Language:
- English
- Description:
- Infections of Unicauda clavicauda (Kudo, 1920) Davis, 1944 (Myxozoa) are described from Notropis hudsonius (Clinton) in Montana. Plasmodia form beneath scales of the body and produced spores within a loosely-defined matrix. Fixed spores are oval in front view, 11-14 pm long and 9-10.5 pm wide, and contain a posterior appendage that is up to 26 pm long. The polar capsules are 4-6 pm long and 2.5-4 pm wide. The study represents the first report of U. clavicauda since the original species description and a new host and geographical record. The taxonomic history of Unicauda Davis, 1944 is summarised and it is concluded the following 10 species are valid members of the genus: U. aristichthydis Zhao et Ma, 1995, U. brachyura (Ward, 1919), U. caudatus (Gogebashvili, 1965), U clavicauda, U. crassicauda (Kudo, 1934), U. lumae Rahemo, 1976, U. macrura (Gurley, 1893), U. magna Minchew, 1981, U. pelteobagrus Ma, 1998, and U. wuhanensis Xiao et Chen, 1993. All of these species have circular, subcircular, or oval spores in frontal view and all parasitise fish of the superorder Ostariophysi. As a group they are known from temperate freshwater locations in North America, Europe and Asia. A list of 16 species described or transferred to Unicauda at one time or another, but not recognised as members of the genus in the present study, is provided.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4. Myxosporeans infecting the gills of bigmouth buffalo (Ictiobus bubalus) in Illinois, USA
- Creator:
- Lom, Jiří and Cone, David
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- Myxosporea, Myxobolus, Ortholinea, and Ictiobus bubalus
- Language:
- English
- Description:
- Four myxosporean species were found on the gills of Ictiobus bubalus from Illinois (USA). Myxobolus endovasus (Davis, 1947) Grinham et Cone, 1990 is revised. Three new species are recorded. Myxobolus enoblei sp. n. has spores ovoid in frontal view, 14.3 x 13 pm in size. Myxobolus morrisonae sp. n. has spores subcircular in frontal view, 10 x 9.5 pm in size; the surface of shell valves appears hairy when studied by SEM. Triangula illinoisensis sp. n. has spores rounded semicircular in frontal view, 10.2 x 12.8 pm in size. Triangula illinoisensis is the fourth species of its genus to be described from fishes.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5. New species of the genera Zschokkella and Ortholinea (Myxozoa) from the Southeast Asian teleost fish, Tetraodon fluviatilis
- Creator:
- Lom, J. and Dyková, I.
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- Myxosporea, Zschokkella, Ortholinea, Kentmoseria, and Tetraodon fluviatilis
- Language:
- English
- Description:
- Three new myxosporean species are described from Tetraodon fluviatilis (Osteichthyes: Tetraodontidae) imported from Southeast Asia to the Czech Republic. Zschokkella tetrafluvi sp. n. lives in the gall bladder. Di- or monosporic plasmodia produce ellipsoidal spores averaging 11.3 x 7.2 pm. Zschokkella pleomorpha sp. n. infects renal tubules and renal corpuscles; mono- to polysporic plasmodia produce spores averaging 15.7 x 7.1 pm. In the process of maturation, immature subspherical spores assume elongated shape. In both species, extremely curved suture line does not bisect poles of the spore. Ortholinea tetrafluvi sp. n. occurs as a rule in mixed infections with Z. pleomorpha sp. n. in the renal tubules. Mono- to polysporic plasmodia produce spores with a wide anterior and a narrow posterior end, averaging 8.3 x 7.8 pm. Both Z. pleomorpha sp. n. and O. tetrafluvi sp. n. have also limited number of stages located within the renal tubule epithelium, where they can complete sporogony. In one of the fish specimens, a myxosporean tentatively identified with Sinuolinea tetraodoni El-Matbou)i et Hoffmann, 1994 was found. A new genus is proposed for Ortholinea alata Kent et Moser, 1990 - Kentmoseria gen. n., and its diagnosis is presented.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
6. Notes on the ultrastructure of two myxosporean (Myxozoa) species, Zschokkella pleomorpha and Ortholinea fluviatilis
- Creator:
- Lom, Jiří and Dyková, Iva
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- Myxosporea, ultrastructure, Zschokkella, and Ortholinea
- Language:
- English
- Description:
- Two myxosporean species, Zschokkella pleomorpha Lom et Dyková, 1995 (Zp) and Ortholinea fluviatilis Lom et Dyková, 1995 (Of) from the kidney of Tetraodon fluviatilis were studied by transmission electron microscope. Coelozoic sporogonie plasmodia of both species use pseudopodia-like projections for attachment to the epithelial cells of renal tubules. These projections either attach to host microvilli forming an interface reminiscent of septate junction (Zp) or are embedded into the epithelial cell surface (Of) or are inserted into gaps between epithelial cells (Zp, Of). Zp produces spores only by direct division of generative cells while in Of pansporoblasts prevail over direct division of generative cells. Sporogonie plasmodia of Zp greatly differ in size and in the variety of cytoplasmic constituents. A special feature in capsulogenesis is a transient envelope encasing the capsular primordium; there are fine fibres on the surface of the nascent filament spaced at 11 nm. In Of, vegetative nuclei of the plasmodium adhere to generative cells in a way reminding of sporoplasmic plasmodium of actinospores. In Of plasmodia, several unusual cytoplasmic structures were observed (membrane bound bodies with fuzzy radial contents or with a central dense inclusion, and endoplasmic reticulum cistemae forming a scalloped network). Of may also form intracellular coelozoic sporogonie plasmodia in the epithelial cells of renal tubules; these stages do not seem to constitute an important part of the life cycle.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
7. Review of Myxosporea of importance in salmonid fisheries and aquaculture in British Columbia
- Creator:
- Kent, M.L., Margolis, L., Whitaker, D.J., Hoskins, G.E., and McDonald, T.E.
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- Myxosporea, salmonids, fisheries, and fish pathology
- Language:
- English
- Description:
- everal myxosporean parasites are of importance in fisheries and aquaculture in British Columbia. The PKX organism and Ceratomyxa shasta Noble, 1950 cause disease and mortality, Kudoa thyrsiles (Gilchrist, 1924) and Henneguya salminicola Ward, 1919 are of importance because they infect somatic muscle, cause unsightly cysts and soft flesh, and thus reduce the market value of the fish. Myxobolus arcticus Pugachev et Khokhlov, 1979, an apparently non-pathogenic species, along with H. salminicola, is used as a biological tag in fishery management. Myxobolus arcticus has also been used in our laboratory as a model for the study of myxosporean life cycles. Other myxosporeans that have been found in salmonids in British Columbia include Myxobolus squamalis (Iverson, 1954), Myxobolus insidiosus Wyatt et Pratt, 1963, Myxidium truitae Léger, 1930, Myxidium salvelini Shuhnan et Konovalov, 1966, Chloromyxum sp., ľarvicapsula sp., and Sphaerospora sp.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
8. Taxonomic problems, seasonality and histopathology of Henneguya creplini (Myxosporea) infection of the pikeperch Stizostedion lucioperca in Lake Balaton
- Creator:
- Molnár, Kálmán
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- Henneguya creplini, Myxosporea, pikeperch, gills, development, and histopathology
- Language:
- English
- Description:
- Plasmodia of a Henneguya species measuring 70-900 pm and exhibiting season-dependent stages of development were detected throughout a three-year study on gill myxosporosis of Lake Balaton pikeperch (Stizostedion lucioperca (L.)). Sixty-five out of 160 fish (41%) examined in the period of study were infected by the parasite. Infection was the most prevalent (48%) among pikeperch specimens exceeding 40 cm in length. The highest prevalence of infection (58%) was recorded in 1995-1996 while the lowest (30%) in 1996-1997. The youngest plasmodia appeared in April, and started to develop within the capillaries of the secondary lamellae of the gill filaments. The round or ellipsoidal plasmodia which continued their gradual growth in the subsequent months of the year achieved a size of 800-900 pm by the late autumn months, but remained in intralamellar location throughout the developmental cycle. Mature spores developed in the plasmodia by the end of winter. On the basis of their shape and size, the spores were identified as Henneguya creplini (Gurley, 1894). However, because of the uncertain taxonomy of species assigned to the genus Henneguya the taxonomic position of the parasite requires further study. The host reaction consisting of epithelial proliferation and granulation tissue formation starts around the infected secondary lamella only after the maturation of spores and the disruption of plasmodia.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
9. Transmission experiments to determine the relationship between Sphaerospora sp. from Atlantic salmon, Salmo salar, and Sphaerospora truttae: a revised species description for S. truttae
- Creator:
- McGeorge, James, Sommerville, Christina, and Wootten, Rod
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- Myxosporea, Myxozoa, Sphaerospora, fish parasites, and salmonids
- Language:
- English
- Description:
- Extrasporogonic stages of Sphaerospora sp. from the kidneys of Atlantic salmon (Salmo salar L.) were successfully transmitted via intra-peritoneal injection to naive Atlantic salmon and brown trout (Salmo trutta L.). Rainbow trout (Oncorhynchus mykiss Walbaum) could not be infected in this way. Transmitted extrasporogonic stages continued their development to form sporogonie stages and mature spores in the kidney tubules. Extrasporogonic stages, sporogonie stages and mature spores of the parasite in both experimentally infected hosts were morphologically identical to the equivalent stage in naturally infected Atlantic salmon, although minor differences were seen in spore dimensions. A farm-based exposure experiment confirmed the susceptibility of brown trout to the salmon Sphaerospora, These results are consistent with the view that the salmon Sphaerospora is Sphaerospora truttae Fischer-Scherl, El-Matbouli et Hoffmann, 1986. The parasite is redescribed according to the guidelines of Lom and Arthur (1989) since details of extrasporogonie stages, the ultrastructure of extrasporogonic and sporogonie stage development, and of the parasite’s epidemiology are known from Atlantic salmon but not from other reports.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public