RESUMEN
In the present study, we combined morphological and phylogenetic methods to characterize Myxobolus pseudonobilis n. sp. infecting Hypophthalmichthys molitrix Valenciennes, 1844 from Chongqing, China. The morphology and molecular characteristics of M. pseudonobilis n. sp. were distinct from those of other previously described Myxobolus species. Mature myxospores were ovoid in frontal view with spore dimensions of 10.0 ± 0.4 (9.3-10.9) µm in length and 8.5 ± 0.2 (7.9-9.0) µm in width. Two polar capsules occupying approximately half of the myxospore length were unequal in size. The larger polar capsule containing 6 to 7 filament coils measured 5.2 ± 0.3 (4.5-5.8) µm in length and 3.6 ± 0.2 (3.2-3.9) µm in width, while the smaller capsule with 4 to 5 filament coils measured 3.9 ± 0.3 (3.0-4.4) µm in length and 2.5 ± 0.3 (2.1-3.6) µm in width. The comparison of molecular characteristics demonstrated similarities and genetic distances of 18S rDNA sequences of 95.19% - 98.20% and 1.82% - 5.46%, respectively, between M. pseudonobilis n. sp. and its morphologically similar species, and secondary structures were also distinctly different. Moreover, phylogenetic analysis showed that M. pseudonobilis n. sp. was clustered with other myxobolids possessing spores with a blunt anterior end and branched independently. In addition, the morphology of myxosporeans as an important indicator was discussed.
Asunto(s)
Carpas , ADN Ribosómico/análisis , Enfermedades de los Peces/epidemiología , Myxobolus/clasificación , Enfermedades Parasitarias en Animales/epidemiología , Animales , Secuencia de Bases , China/epidemiología , Enfermedades de los Peces/parasitología , Branquias/parasitología , Myxobolus/citología , Myxobolus/genética , Myxobolus/aislamiento & purificación , Enfermedades Parasitarias en Animales/parasitología , Filogenia , Prevalencia , Alineación de Secuencia/veterinariaRESUMEN
A previously undescribed Myxobolus sp. was isolated from the cranial nerves and ganglia of the spotfin hatchetfish Thoracocharax stellatus (Kner) that exhibited neurologic signs following importation from Colombia. Associated plasmodia formed space-occupying masses within nerves, compressing neuronal cell bodies and causing axonal degeneration. Myxospores from these fish were morphologically and molecularly distinct from other myxobolids infecting the central nervous system of characins. In valvular view, spores are pyriform with a rounded posterior and tapering anterior aspect. Myxospore bodies are 17.0-19.4 (mean 18.4) µm long and 8.2-9.3 (mean 8.8) µm wide. Polar capsules are asymmetrical and pyriform with a neck-like projection at the apical end. The small polar capsule measures 4.3-5.9 × 2.2-3.1 (mean 5.0 × 2.6) µm, while the large polar capsule measures 9.1-10.7 × 4.9-6.3 (mean 9.9 × 5.4) µm wide. The sequence generated for the small subunit rRNA (18S) gene did not directly match any sequences available on GenBank, but demonstrated 92% nucleotide similarity to Myxobolus axelrodi Camus, Dill, Rosser, Pote & Griffin, 2017 infecting Paracheirodon axelrodi (Schultz). This study provides the first morphological, histological and molecular characterisation of Myxobolus stellatus n. sp. from the spotfin hatchetfish.
Asunto(s)
Characiformes/parasitología , Nervios Craneales/parasitología , Enfermedades de los Peces/parasitología , Ganglios/parasitología , Myxobolus/clasificación , Enfermedades Parasitarias en Animales/parasitología , Animales , Colombia , Myxobolus/citología , Myxobolus/genética , ARN Ribosómico 18S/genéticaRESUMEN
During a parasitological survey of Astyanax altiparanae captured in the Mogi Guaçú river, Pirassununga, state of São Paulo, Brazil, a new species of myxozoa was observed infecting the kidney of 30 of 42 specimens. Plasmodia of the new myxozoa, referred to herein as Unicauda whippsi n. sp. were spherical and varied from 450 to 1000 µm in length. The mature spore was elongated and measured 11 ± 1.2 (10-12) µm long by 5.4 ± 0.6 (4.7-7.2) µm wide. Polar capsules of unequal length with the filament coiled 7-9 times and a unique caudal process characteristic of the genus Unicauda, were recorded. Phylogenetic analysis demonstrated that U. whippsi n. sp. clustered with members of the genus Unicauda and Myxobolus, confirming it's placement within the family Myxobolidae. This is the first record of a species of Unicauda infecting characiform fish, as well as the first registered occurrence of species of this genus in South America.
Asunto(s)
Characidae/parasitología , Enfermedades de los Peces/parasitología , Myxozoa/clasificación , Enfermedades Parasitarias en Animales/parasitología , Animales , Brasil , Riñón/parasitología , Myxobolus/clasificación , Myxobolus/citología , Myxobolus/genética , Myxobolus/aislamiento & purificación , Myxozoa/citología , Myxozoa/genética , Myxozoa/aislamiento & purificación , Filogenia , Ríos/parasitología , EsporasRESUMEN
A new species of myxozoan, Myxobolus imparfinis n. sp. is described based on material from the gills of Imparfinis mirini (Haseman) (Heptapteridae). Mature myxospores are round, measuring 7.1-8.4 (7.9 ± 0.3) µm in length, 4.5-6.2 (5.5 ± 0.5) µm in width and 3.1-4.2 (3.7 ± 0.3) µm in thickness. The polar capsules are of unequal size, the larger polar capsule measuring 3.4-4.5 (3.9 ± 0.3) µm in length and 1.4-2.0 (1.7 ± 0.1) µm in width and the smaller capsule measuring 3.1-3.8 (3.4 ± 0.2) µm in length and 1.2-1.8 (1.5 ± 0.2) µm in width. The polar filament presents 6-7 coils. Spores had a prevalence of infection of 75% (6/8). In histological analyses we detected the development site of spores in primary filaments, in afferent branchial artery, thus classifying the type of infection to the filamental type and vascular subtype. The phylogenetic analyses of a dataset including species Myxobolus Bütschli, 1882 and Henneguya Thélohan, 1892 from South America recovered M. imparfinis n. sp. as a sister species of Myxobolus flavus Carriero, Adriano, Silva, Ceccarelli & Maia, 2013. To our knowledge, this is the first record of a myxozoan species parasitising I. mirini.
Asunto(s)
Bagres/parasitología , Myxobolus/clasificación , Myxobolus/citología , Filogenia , Animales , Brasil/epidemiología , Enfermedades de los Peces/epidemiología , Enfermedades de los Peces/parasitología , Branquias/parasitología , Enfermedades Parasitarias en Animales/epidemiología , Enfermedades Parasitarias en Animales/parasitología , Especificidad de la EspecieRESUMEN
The Indian major carp, Labeo rohita Hamilton, 1822 is a tropical freshwater cyprinid fish native to inland waters in Asia. Herein, we describe a novel myxozoan forming plasmodia in the gill lamellae of L. rohita from Ranjit Sagar Wetland in Punjab, India. Myxospores were consistent with the genus Myxobolus, round to elliptical in valvular view, lemon shaped in side view with a characteristic protrusion at the anterior end and a round posterior end; length 7.65 ± 0.07 µm, width 4.62 ± 0.09 µm. There were two polar capsules of equal length, pear shaped, length of polar capsule 2.54 ± 0.05 µm, width 1.60 ± 0.02 µm, with 5-6 turns of the polar filament. The 890 bp 18S rDNA sequence was up to 97% similar to M. catlae from other cyprinid fishes in India. In having, unique myxospore morphology and 18S rDNA sequence, we propose Myxobolus holzerae as new to science.
Asunto(s)
Cyprinidae/parasitología , Enfermedades de los Peces/parasitología , Branquias/parasitología , Myxobolus/clasificación , Myxobolus/aislamiento & purificación , Animales , ADN Ribosómico/genética , Branquias/patología , India , Myxobolus/citología , Myxobolus/genética , Enfermedades Parasitarias en Animales/parasitología , Filogenia , ARN Ribosómico 18S/genética , Análisis de Secuencia de ADN , Esporas , Virulencia , Agua , HumedalesRESUMEN
A parasitological survey of freshwater fishes in the Big Thicket National Preserve in southeast Texas revealed myxozoan infections in two species of sunfish, Lepomis marginatus Holbrook and Lepomis miniatus Jordan (Perciformes: Centrarchidae). Pseudocysts were elongate-oval, 988 × 485 µm (ex L. marginatus) and 800 × 606 µm (ex L. miniatus) and demonstrated a predilection to the edge of the primary gill lamellae. Myxospores consistent with the genus Myxobolus were oblong, 16.8-21.3 (19.0 ± 0.9) µm long, 7.0-8.8 (7.9 ± 0.5) µm wide and 5.3-6.1 (5.8 ± 0.3) µm thick (ex L. marginatus) and 17.2-20.3 (18.8 ± 0.7) µm long, 7.5-9.9 (8.7 ± 0.6) µm wide, and 6.8-7.2 (7.0 ± 0.2) µm thick (ex L. miniatus); with 2 pyriform polar capsules 8.3-9.8 (9.0 ± 0.5) µm long, 2.2-2.7 (2.5 ± 0.2) µm wide (ex L. marginatus) and 9.2-10.5 (10.0 ± 0.4) µm long, 2.2-3.0 (2.8 ± 0.2) µm wide (ex L. miniatus). Statistically, the measurements of spore body width, polar capsule length, and polar capsule width were significantly different between myxospores from L. marginatus and L. miniatus. However, intraspecific genetic variability between isolates at the 18S rRNA gene was negligible, with < 0.8% variability across > 2,000 bp of sequence. The isolates shared no significant sequence similarity with any myxozoan deposited in the GenBank nucleotide database. Phylogenetic analysis inferred from the 18S rRNA gene from both L. marginatus and L. miniatus placed the isolates within a clade of myxozoan parasites of perciform fishes. Based on shared tissue and host family tropism, overlapping morphological characters and high degrees of sequence conservation at the 18S rRNA gene, we propose these isolates as morphologically distinct, genetically conspecific representatives of M. lepomis n. sp. from the gills of L. marginatus and L. miniatus in the Big Thicket National Preserve in Texas, USA.
Asunto(s)
Branquias/parasitología , Myxobolus/clasificación , Perciformes/parasitología , Animales , Agua Dulce , Variación Genética , Myxobolus/citología , Myxobolus/genética , Filogenia , ARN Ribosómico 18S/genética , Especificidad de la Especie , TexasRESUMEN
The smallmouth buffalo Ictiobus bubalus Rafinesque (Catostomidae) is native to North American waterways and occasionally grown in pond aquaculture. Species of Myxobolus Bütschli, 1882 have been reported from the gills, integument, and intestinal tract of buffalo fish, although there is ambiguity in some host records. In the summer of 2013, thirteen adult smallmouth buffalo were seined from a 0.1-acre (0.04-hectare) experimental research pond at the Thad Cochran National Warmwater Aquaculture Center in Stoneville, Mississippi, USA, and examined for the presence of parasitic infection. Two previously unknown species of Myxobolus were observed parasitising the gills. Plasmodia of the two species differed from each other in both size and shape. Morphologically the two species were distinct from one another and from other Myxobolus spp. previously reported from buffalo fish. Myxospores of Myxobolus ictiobus n. sp. were spherical and measured 12.7-14.5 (13.9 ± 0.4) µm in length and 10.7-13.6 (12.5 ± 0.7) µm in width with a thickness of 10.3-14.8 (12.6 ± 2.3) µm. Polar capsules measured 5.6-7.4 (6.6 ± 0.4) µm in length and 3.7-4.9 (4.5 ± 0.8) µm in width and each contained a coiled polar filament with 5-6 turns. Myxospores of Myxobolus minutus n. sp. were circular in shape and measured 7.4-9.6 (8.6 ± 0.7) µm in length and 7.5-9.9 (8.8 ± 0.7) µm in width with a thickness of 6.5-7.3 (6.7 ± 0.3) µm. Polar capsules measured 3.6-4.9 (4.3 ± 0.3) µm in length and 2.8-3.8 (3.3 ± 0.3) µm and each contained a coiled polar filament with 5-6 turns. Supplemental 18S rRNA gene sequencing identified unique sequences for each isolate. Phylogenetic analysis of 18S rRNA sequences demonstrated a strong clustering of both isolates with other species of Myxobolus from cypriniform fish.
Asunto(s)
Cipriniformes/parasitología , Myxobolus/clasificación , Animales , Branquias/parasitología , Mississippi , Myxobolus/citología , Myxobolus/genética , Filogenia , ARN Ribosómico 18S/genética , Especificidad de la EspecieRESUMEN
Myxobolus niger n. sp. (Myxozoa) is described in the connective tissue of the serosa layer of the gill arch of Corydoras melini (Callichthyidae) captured from the Negro River, Amazonas State, Brazil. The prevalence of the parasite was 20% and the range intensity was 1-2 cysts per fish. The plasmodia were white and spherical to ellipsoidal, measuring 175 µm in diameter and were surrounded by a well-defined capsule of host connective tissue, with distinct delicate and interlaced collagen fibers. The myxospores body was ellipsoidal in frontal view and biconvex in sutural view. Spore dimensions were 11.3 ± 0.4 µm in length, 6.8 ± 0.2 µm in width and 4.1 ± 0.2 µm in thickness. The valves were symmetrical and smooth. The two polar capsules were elongated as pyriform and equal in size, measure 5.0 ± 0.3 µm in length and 2.0 ± 0.1 µm in width. The polar capsule had six to seven polar filament turns. Some aberrant spores were round in shape and had three polar capsules. The sporoplasm was binucleated and contained moderated number of sporoplasmosomes. The development of the plasmodia was asynchronic, with mature and immature spores. The plasmodium had moderated pynocitic channels. There were no projections, no invaginations and no microvilli in the plasmodial wall. This study is the first description of Myxobolus species in the fish of the Callichthyidae family.
Asunto(s)
Bagres/parasitología , Branquias/parasitología , Myxobolus/ultraestructura , Animales , Brasil , Enfermedades de los Peces/parasitología , Myxobolus/citologíaRESUMEN
The common nase Chondrostoma nasus (L.) is a frequent cyprinid fish in the River Danube. In a survey on its infection with myxosporeans, eight different Myxobolus spp. spore types were found in the gills, swim bladder, fins and intestinal wall. Of these, spore types representing three species were studied in detail by morphological and molecular methods. Based on the differences in 18S rDNA sequences, two new species of Myxobolus Bütschli, 1882 from the gills and one from the swim bladder are described: M. arrabonensis n. sp., M. szentendrensis n. sp. and M. paksensis n. sp. The new species resembled M. muelleri Bütschli, 1882, M. intimus Zaika, 1965 and M. cycloides Gurley, 1893, all parasitic in leuciscine cyprinids, in spore size and location in the host, but exhibited differences in partial 18S rDNA sequences as follows: M. arrabonensis - M. muelleri (1.4%), M. szentendrensis - M. intimus (2.8%), M. paksensis - M. cycloides (2.4%). Based on the significant differences in rDNA sequences, the three forms are considered to represent new, hitherto undescribed species in spite of their morphological similarities to some Myxobolus spp. forming spores in identical locations in genetically closely related cyprinids of the subfamily Leuciscinae.
Asunto(s)
Cyprinidae/parasitología , Myxobolus/clasificación , Animales , Datos de Secuencia Molecular , Myxobolus/citología , Myxobolus/genética , Filogenia , ARN Ribosómico 18S/genética , Ríos , Especificidad de la EspecieRESUMEN
Originally, Myxobolus fahmii was described from the gills of Barbus bynni collected from the Nile River, Egypt. The original study provided only mensural characteristics of the spores and referred to gill lamellae as the site for the infection. In this study, B. bynni were collected from almost the same locality, with a similar parasite being found. Our investigations enabled us to determine the precise infection site, which corresponded with the "filamental vascular type" and to provide, for the first time, information on pathogenicity and on the seasonal variation in the prevalence of M. fahmii in gills. The infection was recorded as whitish ellipsoidal plasmodia within the afferent artery of the gill filaments. Due to continuous growth of the plasmodia, gill lamellae were atrophied and obliterated at the plasmodium site. Spores were drop to ovoid shaped with a mean length of 11 µm and mean width of 8 µm. Polar capsules were pear shaped, measuring 7 µm in length × 3.0 µm, with 5-7 filament coils. The overall prevalence of infection was 32.9% (79/240). The highest prevalence was in autumn 63.3% (38/60) while the lowest was in winter 6.6% (4/60). The infection showed a significant difference in prevalence between all the seasons except autumn and spring and summer and winter.
Asunto(s)
Cyprinidae/parasitología , Enfermedades de los Peces/parasitología , Myxobolus/aislamiento & purificación , Enfermedades Parasitarias en Animales/parasitología , Animales , Egipto/epidemiología , Enfermedades de los Peces/epidemiología , Branquias/parasitología , Myxobolus/citología , Enfermedades Parasitarias en Animales/epidemiología , Prevalencia , Ríos , Estaciones del Año , Esporas ProtozoariasRESUMEN
Myxobolus balatonicus n. sp. was detected in the gill filaments of the common carp Cyprinus carpio L. collected in Lake Balaton, Hungary. Its oval plasmodia measuring 600-800 × 300-400 µm were located intravasally in the filamental arteries. The spores measured 11.2 ± 0.92 × 9.5 ± 0.41 × 7.4 ± 0.33 µm and had two equal polar capsules with six filamental turns. Both morphology and DNA sequence analysis revealed that M. balatonicus n. sp. is distinct from the ten species of Myxobolus Bütschli, 1882 described from the European common carp and the 21 species described from the Asian common carp subspecies. Phylogenetic analysis placed M. balatonicus n. sp. in a clade of gill-infecting myxobolids.
Asunto(s)
Carpas/parasitología , Myxobolus , Filogenia , Animales , Datos de Secuencia Molecular , Myxobolus/clasificación , Myxobolus/citología , Myxobolus/genética , ARN Ribosómico 18S/genética , Especificidad de la EspecieRESUMEN
Two Myxobolus spp. are described from the kidney of the Nile tilapia (Oreochromis niloticus) collected from the River Nile, Egypt. The prevalence of infection was 61 % (47/77), with the infected fish in each case parasitized by the two Myxobolus species simultaneously. The infection was exhibited as free spores in Bowman capsules and renal glomeruli, which makes their original structures difficult to discern. In some cases, the infection appeared as a fibrous plasmodia-like structure containing degenerated developmental stages and spores in the interstitium. The paper identifies each species based on the morphological characteristics of its spores and identifies the histological impacts of Myxobolus infection in this species of fish.
Asunto(s)
Cíclidos/parasitología , Enfermedades de los Peces/parasitología , Riñón/parasitología , Myxobolus/clasificación , Enfermedades Parasitarias en Animales/parasitología , Animales , Egipto/epidemiología , Enfermedades de los Peces/epidemiología , Enfermedades de los Peces/patología , Riñón/patología , Myxobolus/citología , Enfermedades Parasitarias en Animales/epidemiología , Enfermedades Parasitarias en Animales/patología , RíosRESUMEN
New myxosporean species are described from Indian fishes cultured in pond farms of Meerut, Uttar Pradesh (UP) state. Based upon plasmodia found in the Indian major carps (Catla catla, Cirrhinus cirrhosus, Labeo rohita and their hybrids), three new Myxobolus spp., Myxobolus basuhaldari sp. n., Myxobolus kalavatiae sp. n. and Myxobolus meerutensis sp. n., are described, and two species, Myxobolus catlae and Myxobolus bhadrensis, are redescribed. Plasmodia of M. basuhaldari sp. n., M. kalavatiae sp. n., M. meerutensis sp. n. and M. catlae developed in small cysts in the gill lamellae, while plasmodia and scattered spores of M. bhadrensis were found in the muscles and kidney, respectively. Plasmodia and spores found in these fishes differed from each other with respect to their morphology, tissue tropism and 18S ribosomal DNA (18S rDNA) sequence. No major pathological changes were found, but severe infections were observed.
Asunto(s)
Carpas/parasitología , Enfermedades de los Peces/parasitología , Myxobolus/clasificación , Enfermedades Parasitarias en Animales/epidemiología , Animales , Secuencia de Bases , ADN Ribosómico/química , ADN Ribosómico/genética , Enfermedades de los Peces/epidemiología , Branquias/parasitología , India/epidemiología , Datos de Secuencia Molecular , Myxobolus/citología , Myxobolus/aislamiento & purificación , Enfermedades Parasitarias en Animales/parasitología , Filogenia , Estanques , ARN Ribosómico 18S/genética , Análisis de Secuencia de ADN/veterinaria , Esporas , TropismoRESUMEN
Two new myxosporean species, Myxobolus marumotoi n. sp. and Cardimyxobolus japonensis n. sp. (Myxozoa: Myxosporea: Bivalvulida), are described from the dark sleeper, Odontobutis obscura, in Japan, based on their morphological and molecular characterizations. Plasmodia of M. marumotoi n. sp. (Myxobolidae) grew in the myofiber of trunk muscles, forming pseudocysts. The rounded spore was relatively large, measuring 13.3-15.0 µm (average 13.8) in length, 14.2-15.0 µm (14.6) in width, and 10.0-11.7 µm (10.8) in thickness, with two subspherical polar capsules of 7.9-9.6 µm (8.4) in length by 5.4-6.3 µm (5.9) in width (n = 15). The polar capsules were directed toward the apex of the spore, packing five to six spirals of the polar filament. Plasmodia of C. japonensis n. sp. (Ortholineidae) were surrounded by thin fibrous tissue, forming cysts in the lamina propria of the alimentary tract. The spore was ovoid, wider than long, in valvular view and spindle-shaped in sutural view. It measured 8.8-10.4 µm (9.4) in length, 11.3-12.5 µm (11.9) in width, and 5.2-6.7 µm (5.8) in thickness, with two ovoid polar capsules of 4.2-5.0 µm (4.7) in length by 2.9-3.8 µm (3.3) in width (n = 15). The shell valves of spores often showed a flattened anterior border and semicircular posterior border, and the two polar capsules were directed toward opposite lateral sides. In addition, the sporoplasm contained an iodinophilous vacuole. Almost complete small-subunit (SSU) rDNA sequences, except for primer flanking regions, were obtained for both species; 1,996 bp long for the former and 1,588 bp long for the latter. On phylogenetic trees based on the SSU rDNA sequences of representative species of Bivalvulida, M. marumotoi n. sp. and C. japonensis n. sp. formed a distinct branch in the Henneguya/Myxobolus clade or near but outside this clade, respectively. This study is the first report of the genetic characterization for the genus Cardimyxobolus.
Asunto(s)
Myxobolus/clasificación , Myxozoa/clasificación , Perciformes/parasitología , Animales , Secuencia de Bases , ADN Ribosómico/genética , Enfermedades de los Peces/parasitología , Japón , Músculos/parasitología , Myxobolus/citología , Myxobolus/aislamiento & purificación , Myxozoa/citología , Myxozoa/aislamiento & purificación , Filogenia , Esporas/citologíaRESUMEN
In the present study, we isolated three populations of Myxobolus ampullicapsulatus from the gills of crucian carp, Carassius auratus auratus, two from Yongchuan, Chongqing area and one from Poyang Lake, Jiangxi area, China, sequenced their complete small subunit ribosome RNA gene, analyzed their genetic distance and gene similarity, and explored their relationship based on Bayesian inference and maximum likelihood analyses of their small subunit ribosomal DNA. The results combined with their morphological characteristics suggest that M. ampullicapsulatus infecting the gills and pharynx of allogynogenetic gibel carp, Carassius auratus gibelio, should be Myxobolus honghuensis. This study highlights the importance of DNA sequence comparisons for distinguishing Myxobolus species and indicates that the intra-species identification for the two Myxobolus species mentioned in the present research should be less than ten variation sites. In morphology, M. honghuensis Liu et al. (2012) parasitic on the gills of C. auratus auratus (goldfish) was collected from Chongqing area, and its mature spore was 16.5-19.5 × 8.5-10.0 µm in size, polar capsule was 7.0-10.0 × 2.5-4.0 µm in size, and polar filament had 9-10 coils. M. honghuensis Liu et al. (2012) isolated from the pharynx of C. auratus gibelio was sampled in Hubei area, and its mature spore was 15.1-19.5 × 9.0-11.3 µm in size, polar capsule was 7.9-8.1 × 3.0-4.5 µm in size, and polar filament had 7-8 coils.
Asunto(s)
Variación Genética , Myxobolus/clasificación , Myxobolus/aislamiento & purificación , Animales , Carpas/parasitología , China , Análisis por Conglomerados , ADN Protozoario/química , ADN Protozoario/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Genes de ARNr , Branquias/parasitología , Datos de Secuencia Molecular , Myxobolus/citología , Myxobolus/genética , Filogenia , ARN Protozoario/genética , ARN Ribosómico 18S/genética , Análisis de Secuencia de ADNRESUMEN
OBJECTIVE: The aim of this study was to investigate the gill filaments of Labeo bata in India parasitologically and to describe the new Myxozoa parasite species, Myxobolus leafa sp. nov., which was determined. METHODS: Fish were collected alive from fish farms from Manipur (India). Sporogonic plasmodia were removed with sterile forceps and observed under phase contrast microscope. For permanent preparations, air dried smears were stained with Giemsa after fixation in acetone free absolute methanol. RESULTS: Mature spores of the new species appear as leaf-like structures in valvular or frontal view, tapering at both ends. The anterior end of the spore is broader than the posterior end. Spores measure 15.3-11.8 µm (16.91 ± 1.16) in length and 13.6-15.3 µm (14.15 ± 0.67) in breadth. CONCLUSION: The new gill parasite species, Myxobolus leafa sp. nov., was described from fish in India. The prevalence of the parasite was 3.3% and two stages (cyst and spore) of the parasite existed in its life cycle.
Asunto(s)
Cyprinidae/parasitología , Enfermedades de los Peces/parasitología , Branquias/parasitología , Myxobolus/clasificación , Myxobolus/aislamiento & purificación , Enfermedades Parasitarias en Animales/parasitología , Animales , India , Estadios del Ciclo de Vida , Microscopía , Myxobolus/citología , Esporas/citologíaRESUMEN
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 7.0 µm (6.2-7.6) in length, 5.2 µm (4.0-6.2) in width, and 4.9 µm (3.8-6.0) in thickness. Polar capsules contained a polar filament with five to six turns and measured 3.5 µm (2.5-4.5) in length and 2.0 µm (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.
Asunto(s)
Myxobolus/aislamiento & purificación , Enfermedades Parasitarias en Animales/parasitología , Smegmamorpha/parasitología , Estructuras Animales/parasitología , Estructuras Animales/patología , Animales , ADN Protozoario/química , ADN Protozoario/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Genes de ARNr , Histocitoquímica , Corea (Geográfico) , Microscopía , Datos de Secuencia Molecular , Myxobolus/clasificación , Myxobolus/citología , Myxobolus/genética , Enfermedades Parasitarias en Animales/patología , ARN Protozoario/genética , ARN Ribosómico 18S/genética , Análisis de Secuencia de ADNRESUMEN
During a survey of myxozoan parasites of common carp Cyprinus carpio in Honghu Lake, Hubei Province, China, a parasite was collected that was identified as Myxobolus dispar based on an earlier description from China. However, the small subunit ribosomal DNA of this species shared only 90 % similarity with M. dispar, instead matching M. musseliusae with 100 % identity. To resolve this apparent taxonomic conflict, the validity of M. dispar reported from China was investigated. The species encountered here and in the earlier report from China both bear spores that are notably smaller than those of M. dispar in Europe. In the present study, a mucous envelope was adhered to the posterior of many fresh spores and was observed to expand and surround the spore. This structure has never been reported from fresh spores of M. dispar. Histology showed extravascular plasmodia in the gill filaments in close contact with the cartilaginous ray of the filament, which contrasts with the plasmodia of M. dispar which develop in the arteries of the gill filaments. Phylogenetically, the current species is distinct from M. dispar, instead forming a sister group with M. musseliusae. The data presented here allow us to conclude that the species isolated is M. musseliusae and that prior reports of M. dispar in China are unsubstantiated.
Asunto(s)
Carpas/parasitología , Enfermedades de los Peces/parasitología , Branquias/parasitología , Myxobolus/clasificación , Myxobolus/aislamiento & purificación , Enfermedades Parasitarias en Animales/parasitología , Animales , China , Análisis por Conglomerados , ADN Protozoario/química , ADN Protozoario/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Enfermedades de los Peces/patología , Genes de ARNr , Histocitoquímica , Microscopía , Datos de Secuencia Molecular , Myxobolus/citología , Enfermedades Parasitarias en Animales/patología , Filogenia , ARN Protozoario/genética , ARN Ribosómico 18S/genética , Análisis de Secuencia de ADNRESUMEN
While studying Myxobolus gill infections of cyprinid fishes, the authors found large, segmented plasmodia in three species: ide (Leuciscus idus), asp (Aspius aspius) and white bream (Blicca bjoerkna). As regards their size and morphology, the spores from these plasmodia corresponded to those of M. dujardini described from chub (Leuciscus cephalus). However, the 18S rDNA sequences of spores from the three cyprinids differed from those of M. dujardini. Based on molecular differences, this paper describes two new species: M. alvarezae sp. nov. from ide and asp, and M. sitjae sp. nov. from white bream. The two new species and M. dujardini had a similar tissue tropism, and infected the multilayered epithelium of the gill filaments. Histological examination of the infected filaments demonstrated that the large plasmodia with multiple buddings were formed from amalgamating small plasmodia. Besides carrying infection in the filamental epithelium, the three above fish species were infected by small intralamellar plasmodia as well. These plasmodia were filled by spores that resembled the roach parasite M. intimus both in morphology and seasonal development. The 18S rDNA sequences of 'intimus-like' spores from ide and asp differed only in some base pairs from spores found in the type host roach, and were identified as belonging to M. intimus. The spores found in white bream, however, showed 3.6-5.0% difference in DNA sequence from those of M. intimus; therefore, they have been described as M. eirasianus sp. nov. The aim of this paper was to demonstrate the importance of using molecular methods for separating and identifying morphologically corresponding or closely similar Myxobolus spp.
Asunto(s)
Cyprinidae/parasitología , Enfermedades de los Peces/parasitología , Myxobolus/clasificación , Myxobolus/aislamiento & purificación , Enfermedades Parasitarias en Animales/parasitología , Animales , Análisis por Conglomerados , ADN Protozoario/química , ADN Protozoario/genética , ADN Ribosómico/química , ADN Ribosómico/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Genes de ARNr , Branquias/parasitología , Microscopía , Datos de Secuencia Molecular , Myxobolus/citología , Myxobolus/genética , Filogenia , ARN Protozoario/genética , ARN Ribosómico 18S/genética , Análisis de Secuencia de ADN , Esporas Protozoarias/citología , TropismoRESUMEN
Tor tambroides, a common and appreciated cyprinid fish of the Tasik Kenyir water reservoir in Malaysia, is one of the species selected for propagation. This fish was first successfully propagated in Malaysia by the Department of Agriculture, Sarawak, Malaysia, and the breeding program continued throughout the country. The gills were frequently infected by a Myxobolus species to be described as Myxobolus tambroides sp. n. The small, 50 to 70 µm, round plasmodia of this species is located intralamellarly. Plasmodia were filled with pyriform myxospores, 9.9 and 7.4 µm wide. In sutural view, the caudal end of the myxospores had a distinctive valvular groove, parallel with the suture. Plasmodia caused deformations on the affected and the neighbouring gill lamellae. The 18S rDNA sequence of M. tambroides sp.n. did not show a close relationship with any other Myxobolus spp., represented in the GenBank. This might be an emerging parasite likely to impact the propagation of this fish.