Cyst-like Plasmodia Research Articles

Morphological, histological, and molecular evidence of Myxobolusspinacurvatura(Cnidaria: Myxosporea) from Mugilcephalus in the Turkish Black Sea coast

In the present study, a total of 30 M. cephalus captured from the Samsun coast of the Black Sea, Turkey were examined for myxozoa infections. Different sizes of whitish and rounded cyst-like plasmodia were macroscopically detected in the liver and intestine wall of M. cephalus. Morphological and histological examinations were performed. The SSU rDNA was amplified using nested PCR and myxosporean-specific primers. The present Myxobolus species was identified as M. spinacurvatura based on the spore morphology and host/organ specificity. In the present study, morphological, histological, and molecular data on M. spinacurvatura were presented. Furthermore, BLASTn research showed that SSU rDNA sequences of M. spinacurvatura (accession number MH374629) were identical to that of the reference sequence of M. spinacurvatura (accession from AF378341) recorded previously. The current study includes the first record and molecular evidence of M. spinacurvatura infecting M. cephalus from the Turkish waters. To date, there is no report on comprehensive morphological, histopathological, and molecular data of M. spinacurvatura in M. cephalus as a typical host. Moreover, the new valid SSU rDNA sequence of M. spinacurvatura (accession number MH374629) was the second record in the GenBank. The present SSU rDNA sequence can also be used to construct a phylogenetic tree with other mugiliform-infecting Myxobolus species worldwide.

New data on wild grey mullet (mugil cephalus linnaeus, 1758) myxosporean (myxobolus episquamalis egusa et al., 1990) in the black sea

Flathead grey mullet, Mugil cephalus, with mass whitish cystlike plasmodia on their scales were collected at Kerchensky preglass of the Black Sea in 2015. The prevalence of infected fish varied from 15% in spring, reached 100% in summer, and declined to 2.5% in autumn. No fish mortality was detected. The spores were oval in frontal view, tapering to a blunt apex. Two unequal polar capsules were pyriform and extended over the anterior half of spore. Spores were 8.2±0.03 µm (7.9-8.4) long, 5.9±0.23 µm (5.2-7.3) wide, and 4.4±0.17 µm (4.0-4.7) thick. Two pyriform and unequal polar capsules were observed (4.0±0.07 µm (3.3-4.5) long, and 1.5±0.24 µm (1.1-1.8) wide). The investigation of nucleotide sequences of the 18S rDNA gene of the myxosporean spores from scales with universal primer А (5′-ACCTGGTTGATCCTGCCAGT-3′) and В (5′-TGATCCTTCTGCAGGTTCACCTAC-3′) showed 100% identity with episquamalis, and 99 % with M. bizerti, M. ichkeulensis, M. spinacurvata and Myxobolus sp. previously detected in mullets. The results obtained from the present study reveal that M. episquamalis, found on the scales of M. cephalus from Kerchensky preglass of the Black Sea, is new record for Russian waters.

Morphometric and molecular characterization of Thelohanellus catlae infecting the gills of Indian major carp catla, Catla catla (Hamilton, 1822) from West Bengal, India

The morphometric and molecular characterization of Thelohanellus catlae a new myxozoan belonging to genus Thelohanellus Kudo, 1933 (Myxosporea:Bivalvulida) infecting the gills of Catla catla were described in this study. The infection was observed as irregular, milky whitish, cyst-like plasmodia (up to 2.0-3.0 mm in diameter) attached to the gill filaments of the host fish. Each spore has a single pyriform polar capsule. Spores measured about 20.4±0.69 (19.3-21.4) × im long and 11.5± 0.63 (10.7-12.4) im wide. The polar capsule was 12.3±0.70 (10.7- 13.9) im long and 10.95± 0.28 (9.7-12.9) im wide. Sequencing of 18S rRNA gene of the new myxozoan revealed 98% sequence homology between the 18S rRNA gene of T.catlae. Phylogenetic analysis showed T. catlae within the clade of gill infecting myxosporeans and closed together with T. catlae. The importance of myxosporeans introduction to new locations along with infected cultured host is emphasized.

Morphological and molecular characterization of Myxobolus dibombensis sp. n. (Myxozoa: Myxobolidae), a parasite of the African carp Labeobarbus batesii (Teleostei: Cyprinidae) from Dibombe River, Cameroon.

Myxobolus dibombensis sp. n. (Cnidaria: Myxosporea: Bivalvulida) is described from the fins of the African carp, Labeobarbus batesii, based on morphological and molecular data. Prevalence of infection was 51.9% (67/129). Ovoid to spherical cyst-like plasmodia were found in the intrasegmental region and among the fin rays. No pathological changes were found in the fish host tissue surrounding the cyst-like plasmodia. Mature myxospores were ovoid in frontal view and lenticular in lateral view, with slightly truncated anterior and rounded posterior ends. Myxospores measured 16.8 (15.8-18.0) μm long and 11.4 (10.0-13.0) μm wide. There was a triangular intercapsular appendix measuring 3.8 (2.6-4.5) μm long. Polar capsules were ovoid and slightly unequal in size, occupying approximately one-third of the myxospore length. The larger polar capsule measured 7 (6-8) μm long and 3.6 (3-4) μm wide, while the smaller one measured 5.8 (4.8-7.0) μm long and 3 (2-4) μm wide. The larger polar capsule contained nine to 11 filament coils, whereas the smaller one contained seven to nine coils. SSU rDNA gene sequence of M. dibombensis sp. n. did not match any sequences available in the GenBank. The similarity with available Myxobolus spp. sequences ranged from 65 to 81%. The novel species clustered with M. algonquinensis, which infects the cyprinid Luxilus cornutus from Canada.

Myxobolus saladensis sp. nov., a new species of gill parasite of Mugil liza (Osteichthyes, Mugilidae) from Samborombón Bay, Buenos Aires, Argentina

Myxosporean Myxobolus saladensis sp. nov. in the gills of Mugil liza Valenciennes, 1836 from Samborombón Bay was described by light and electron microscopy studies. Spores were pyriform and binucleated, measuring 10.63±0.36 µm (n=20) long, 9.24±0.50 µm (n=20) wide and 4.13±0.36 µm (n=20) thick, included in polysporic cyst-like plasmodia. Elongated pyriform polar capsules were of equal size (3.84±0.27 µm long and 2.30±0.12 µm wide). The sporoplasm contained some sporoplasmosomes. Each PC contained a polar filament with 4-5 coils obliquely arranged in relation to the polar capsules axis. The PC wall was composed of two layers of different electron densities. Based on the morphological and ultrastructure differences of the spore to those of previously described species of Myxobolus, we describe a new species, Myxobolus saladensis sp. nov.

Supplementary studies and the first molecular data on Myxobolus scardinii Reuss, 1906 (Myxozoa: Myxosporea) infecting the gill filaments of rudd, Scardinius erythrophthalmus (L.).

Within the present study, we offer new information on the morphology, histopathology, and 18S ribosomal DNA (rDNA) sequence of Myxobolus scardinii to supplement and revise the original description of Reuss (Bull Acad Imp Sci St-Pétersbourg, V Serie, XXV, No. 3: 199-205, 1906). M. scardinii was found infecting the gills of 6 of 125 specimens (4.8%) of Scardinius erythrophthalmus from northern Turkey. Large mature plasmodia, whitish, spherical, or ellipsoidal, measuring 0.9-1.0 mm in diameter, macroscopically occurred in the gills. Histopathological examination indicated that development of the cyst-like plasmodia was intrafilamental-vascular type. Mature spores are oval or shortly ellipsoidal. The spores are 12.1 ± 0.2 (11.5-12.6) μm long, 8.9 ± 0.3 (8.4-9.2) μm wide, and 6.1 ± 0.3 (5.9-6.2) μm thick. The two polar capsules are equal in size, 4.8 ± 0.2 (4.7-5.1) μm long and 2.8 ± 0.2 (2.7-3.1) μm wide, and are long pyriform in shape. A well-developed intercapsular appendix was found in the fresh spores. In this study, a specific gill myxosporean of S. erythrophthalmus, M. scardinii the identity of which was confirmed by careful morphological and histopathological examination, was sequenced with its 18S rDNA sequence for the first time and submitted to Genbank database (accession number KJ562362). Phylogenetic analysis of the 18S rDNA gene revealed that M. scardinii had the closest similarity to M. muelleri and M. bramae. This is the first molecular data for the validity of M. scardinii in S. erythrophthalmus. This new valid genetic data (KJ562362) has been used to establish phylogenetic relationships with other similar gills Myxobolus species from Eurasia.

Myxobolus anatolicus sp. nov. (Myxozoa) infecting the gill of Anatolian khramulya Capoeta tinca (Cyprinidae) in Turkey.

This work is part of an ongoing investigation into the characteristics of myxozoan parasites of freshwater fish in Turkey and was carried out using morphology, histopathology and molecular analysis. A new species of the genus Myxobolus (M. anatolicus sp. nov.) was found infecting the gills of 3 of 34 specimens (8.8%) of Anatolian khramulya Capoeta tinca from the Samsun Province, Northern Turkey. Both morphology and 18S rDNA sequence data revealed that M. anatolicus sp. nov. was distinct from other Myxobolus species found in the gills of cyprinid fishes. The small, white and round-shaped plasmodia, measuring 0.2 to 1.4 mm in diameter, were observed macroscopically in the gills. Histological analysis revealed that the cyst-like plasmodia have an intralamellar-vascular type development. Mature spores of M. anatolicus sp. nov. were oval in both frontal and sutural views, and tapered at the anterior poles. The spores were 10.1 ± 0.41 (9.4 to 10.7) µm long, 6.9 ± 0.28 (6.6 to 7.2) µm wide, and 4.5 ± 0.36 (4.4 to 4.6) µm thick. The 2 polar capsules were pyriform, equal in size, 4.6 ± 0.45 (4.4 to 4.8) µm long and 2.1 ± 0.12 (2 to 2.3) µm wide. Polar filaments within the polar capsules were coiled with 5 or 6 turns. Phylogenetic analysis placed M. anatolicus sp. nov. in a clade of gill-infecting myxobolids. This is the first record of a Myxobolus species infecting Anatolian khramulya Capoeta tinca, and the first record of this species from Eurasia.

Morphologic and Genetic Evidence for Mixed Infection with Two Myxobolus Species (Myxozoa: Myxobolidae) in Gray Mullets, Mugil cephalus, from Korean Waters

The present study was performed to trace the decisive evidence for mixed infection of 2 Myxobolus species, M. episquamalis and Myxobolus sp., in the gray mullet, Mugil cephalus, from Korean waters. Mullets with whitish cyst-like plasmodia on their scales were collected near a sewage plant in Yeosu, southern part of Korea, in 2009. The cysts were mainly located on scales and also found in the intestine. The spores from scales were oval in a frontal view, tapering anteriorly to a blunt apex, and measured 7.2 µm (5.8-8.0) in length and 5.3 µm (4.7-6.1) in width. Two polar capsules were pyriform and extended over the anterior half of the spore, measuring 3.5 µm (2.3-4.8) in length and 2.0 µm (1.5-2.2) in width. In contrast, the spores from the intestine were ellipsoidal, 10.4 µm (9.0-11.9) in length and 8.4 µm (7.3-10.1) in width. The polar capsules were pyriform but did not extend over the anterior half of the spore, 3.7 µm (2.5-4.5) in length and 2.2 µm (1.8-2.9) in width. The nucleotide sequences of the 18S rDNA gene of the 2 myxosporean spores from scales and intestine showed 88.1% identity to each other and 100% identity with M. episquamalis and 94.5% identity with M. spinacurvatura from mullet, respectively. By the above findings, it is first confirmed that mullets from the Korean water are infected with 2 myxosporean species, M. episquamalis and Myxobolus sp.

Thelohanellus niloticus sp. nov. (Myxozoa: Myxosporea), a parasite of the Nile carp Labeo niloticus from the River Nile, Egypt

In the present study, the morphology and morphometric characterization of Thelohanellus niloticus sp. nov., a new myxozoan belonging to genus Thelohanellus Kudo, 1933 (Myxosporea, Bivalvulida) infecting the gills of Labeo niloticus (Osteichthyes, Cyprinidae), were described for the first time from the River Nile at El-Minia Governorate, Egypt. Forty-one out of 78 (52.6%) of the examined fish were infected. The infection was observed as irregular, milky whitish, cyst-like plasmodia (up to 0.8mm in diameter) attached to the gill filaments of the host fish. These plasmodia contained tear-shaped myxospores with slightly tapering anterior and rounded posterior ends. Each spore has a single pyriform polar capsule. Spores measured about 23.3 ± 0.3 (20.4-27.1) μm long and 13.4 ± 0.4 (11.5-14.2) μm wide. The polar capsule was 11.7 ± 0.3 (9.2-12.5) μm long and 4.7 ± 0.3 (3.5-6.2) μm wide, containing a polar filament coiled perpendicular to the longitudinal axis of the spore body making eight turns. Occasionally, an oblong, irregular-shaped mass of protoplasm with a slightly oval nucleus (1.4μm in diameter) and a small iodinophilous vacuole measured 0.85 ± 0.2μm (0.73-1.2μm) were observed in the spore. Due to the lack of the second polar capsule characterizing Myxobolus sp., the present parasite is placed within the genus Thelohanellus. Based on morphological differences (compared with other members of Thelohanellus Kudo, 1933) and the host specificity, this species is described as a new one of the genus Thelohanellus recorded for the first time in Egypt.

Infection of wild mullet (Mugil cephalus) with Myxobolus episquamalis in Korea

Wild mullet (Mugil cephalus) with white cysts on their scales were obtained from Yeosu on the south coast of Korea in 2009. Cyst-like plasmodia consisted of a large number of mature myxosporean spores and numerous sporogonic stages. Spores were oval-shaped in their front view, tapering anteriorly to a blunt apex, and lenticular in their lateral view. They measured 7.0μm (6.2-7.6) in length, 5.2μm (4.0-6.2) in width, and 4.9μm (3.8-6.0) in thickness. Polar capsules contained a polar filament with five to six turns and measured 3.5μm (2.5-4.5) in length and 2.0μm (1.6-2.3) in width. Nucleotide sequences of the 18S rRNA gene of the myxosporean parasites in our study showed 99.8% identity with Myxobolus episquamalis Egusa, Maeno and Sorimachi, 1990 from mullet in Tunisia. These results suggest that the Myxobolus sp. found on the scales of wild mullet is M. episquamalis. In the histopathological examination, spores were observed not only in the plasmodia on the scales, but also in the intestine, pancreas, heart, kidney, stomach, gill, skin, spleen, and liver, suggesting the possibility of the coinfection by different Myxobolus species.

Validity, impacts and seasonal prevalence of Henneguya species infecting catfish Clarias gariepinus from River Nile, Egypt

The validity, impacts and seasonal prevalence of Henneguya suprabranchiae infecting Clarias gariepinus from the River Nile were studied. The overall prevalence was 35% (84/240) with maximum rate of infection in spring and minimum rate of infection in summer. The development of the cyst-like plasmodia was "the intrafilamental type'. Henneguya suprabranchiae is a pathogenic species as the parasite showed high intensity of infection which led to deformation of the filament structure and complete disappearance of the gill lamellae. The validity of H. suprabranchiae compared to the other described species of the same host was discussed.

Light and electron microscopic studies on Myxobolus egyptica sp. nov. (Myxozoa, Myxosporea), infecting the hornlip mullet Oedalechilus labiosus from the Red Sea

AbstractA new myxosporean, Myxobolus egyptica sp. nov., was described from the gills of the hornlip mullet Oedalechilus labiosus, collected from the Red Sea at Al-Quseir city, Egypt. The prevalence of infection was 12/72 (16.66%). Myxobolus egyptica was identified on the basis of spore morphometry, histology and transmission electron microscopy. It was distinguished from all previously reported Myxobolus spp. by its shape, dimensions of the mature spore 10.0 ± 0.6 (9.5–10.5) μm in length, 8.5 ± 0.4 (8.0–9.0) μm in width and 8.7 ± 0.5 (8.4–9.2) μm in thickness, polar capsules, locality and host. The parasite formed intrafilamental cyst-like plasmodia. These plasmodia caused curling and atrophy of the gill lamellae. The ultrastructural analysis revealed a double-unit plasmodial membrane which was in direct contact with the host cells and had numerous vesicles. Some mitochondria were found below this membrane. The disporic pansporoblast was earliest recognizable stage of sporogenesis. Advanced developmental stages of spores and mature spores were reported.

Light and electron microscopical data on the spores of Thelohanellus rhabdalestus n. sp. (Myxozoa: Myxosporea), a parasite of a freshwater fish from the Kwanza River, Angola

The myxosporean Thelohanellus rhabdalestus n. sp. (Myxozoa: Bivalvulida), a parasite of the freshwater fish Rhabdalestes maunensis (Fower) collected from the Kwanza River, Angola, is described based on light and electron microscopical studies. The parasite occurs in irregular, milky-whitish, cyst-like plasmodia (up to 0.8mm in diameter) in close contact with the liver and heart. The spores are pyriform, with slight tapering anterior and round posterior ends, and measure 16.8±0.5μm (n=50) long, 10.2±0.6μm (n=50) wide and 5.6±0.8μm (n=25) thick. The spore wall is partly surrounded by a discontinuous, closely adhered, external coat of electron-dense material of variable thickness (up to c.35nm). A single flask-shaped polar capsule [7.2±0.3μm (n=50) long and 4.0±0.4μm (n=50) in diameter] lies close to the apex of the spores and contains a polar filament with six or seven (rarely eight) coils oblique to its longitudinal axis. Based on morphological and ultrastructural differences, compared with other members of Thelohanellus Kudo, 1933, and judging from the host-specificity of previously described species, we consider this species new to science. This is the first reported myxosporean from the Angolan fauna.

Light and electron microscopy of Myxobolus sciades n. sp. (Myxozoa), a parasite of the gills of the Brazilian fish Sciades herzbergii (Block, 1794) (Teleostei: Ariidae)

A myxosporean parasite in the gill lamellae of the freshwater teleost fish, Sciades herzbergii (Ariidae) (Block, 1794), from the Poti River (Northeast of Brazil) was described by light and electron microscopy studies. Polysporic histozoic cyst-like plasmodia containing several life-cycle stages, including mature spores, were observed. The spores were pyriform and uninucleate, measuring 9.15 +/- 0.39 microm (n = 50) long, 4.36 +/- 0.23 microm (n = 25) wide and 2.61 +/- 0.31 microm (n = 25) thick. Elongated pyriform polar capsules (PC) were of equal size (4.44 +/- 0.41 microm long and 1.41 +/- 0.42 microm in diameter) and each contained a polar filament with 9-10 coils obliquely arranged in relation to the axis of PC. The PC wall was composed of two layers of different electron densities. Histological analysis revealed the close contact of the cyst-like plasmodia with the basal portion of the epithelial gill layer, which exhibited some alterations in the capillary vessels. Based on the morphological and ultrastructural differences, the similarity of the spore features to those of the genus Myxobolus and the specificity of this host to previously described species, we describe a new species named Myxobolus sciades n. sp. in this study.

Light and Electron Microscopy of the Spore of Myxobolus heckelii n. sp. (Myxozoa), Parasite from the Brazilian Fish Centromochlus heckelii (Teleostei, Auchenipteridae)

A myxosporean parasitizing the gill filaments of the freshwater teleost fish Centromochlus heckelii collected in the Tocantins River (Lower Amazonian Region, Brazil) is described using light and electron microscopy. This parasite produces spherical to ellipsoidal cyst-like plasmodia up to 250 mum in diameter, with a thick wall strengthened by several stratified juxtaposed crossed collagen layers, whose thickness varies according to the number of the layers. Several compressed fibroblasts are observed among the collagen fibrils. Deposits of spherical dense material are scattered at the internal periphery of the cysts. Plasmodia and different developmental stages, including immature and mature spores, filled the central region of the cysts. The spore body is ellipsoidal in valvar view and biconvex in sutural view. It is formed by two equal-sized and symmetric valves measuring 12.7 microm long (12.2-13.1) (n=50), 6.6 microm wide (6.3-6.9) (n=25), and 4.0 microm (3.7-4.4) (n=20) thick. A thin layer formed by fine and anastomosed microfibrils is observed at the spore surface. Two equal, elongated pyriform polar capsules measure 2.9 microm (2.7-3.3) x 1.7 microm (1.4-2.0) (n=25), each containing four or five oblique polar filament coils. The binucleated sporoplasm contains numerous spherical sporoplasmosomes, glycogen particles, and a large vacuole with fine granular matrix. Based on the morphological and ultrastructural differences and specificity of the host, we describe this isolate as a new myxosporidian, Myxobolus heckelii n. sp. (Myxozoa, Myxosporea).

New data on Myxobolus longisporus (Myxozoa: Myxobolidae), a gill infecting parasite of carp, Cyprinus carpio haematopterus, from Chinese lakes.

The original description of Myxobolus longisporus Nie et Li, 1992, the species infecting gills of Cyprinus carpio haematopterus L., is supplemented with new data on the spore morphology and pathogenicity. Spores are elongate pyriform with pointed anterior end, 15.7 (15.5-16.5) microm long, 6.7 (6-8) microm wide and 5.5 microm thick. Sutural ridge is straight and narrow. Mucus envelope is lacking. Two equal-sized elongate pyriform polar capsules are 8.5 microm long and 2.5 microm wide with convergent long axes. Polar filament coiled perpendicularly to the long axis of the capsule makes 9 (8-10) turns. Posterior end of polar capsules exceeds mid-spore by 15-20%. Cyst-like plasmodia are localised in the gill secondary lamellae. The infection is described in adult big host specimens. Gross lesions manifested as dark red colouration of gill tissues were restricted to the ventral part of the first gill arches. Remarkable site specificity (apical part of secondary lamellae) was observed in the course of development of microscopic lesions. M. longisporus is characterised also on the molecular level using sequences of SSU rRNA gene. Phylogenetic analysis based on these sequences has allowed clearer phylogenetic relationships to be established with other species of the genus Myxobolus sequenced to date.

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.

Henneguya malabarica sp. nov. (Myxozoa, Myxobolidae) in the Amazonian fish Hoplias malabaricus.

Henneguya malabarica sp. nov. is described from the Amazonian teleost fish Hoplias malabaricus Boch, 1794, collected from the estuarine region of the Amazon river near Belém, Brazil. Plasmodia were represented by several vegetative nuclei, generative cells, and sporogony stages contained in cyst-like plasmodia. The spore body was ellipsoidal (12.6 microns in length and 4.8 x 3.6 microns in width) and each valve presented a tapering tail (17.1 microns in length). Thin valves surrounded the binucleate sporoplasm cell and two spherical polar capsules (3.7 x 1.8 microns) that contain five to six coils of the polar filament. The spore had an iodinophilous vacuole. The basal portion of the spore body of immature and mature spores and the whole surface of the tails were surrounded by a close homogeneous sheath. The prevalence of infection was 6.7% in the fish examined. The spores differed from those of previously described species of Henneguya in their shape, size, spore, and arrangement of the polar-filament coil. The taxonomic affinities of this parasite to other species are discussed.