Synopsis of tailed Myxobolidae (Cnidaria, Myxozoa, Myxosporea) infecting Indian fishes.

A synopsis of 43 nominal species from five genera of tailed Myxobolidae infecting Indian freshwater and marine fishes is presented. The main characteristic of this group is the presence of at least one tail-like caudal process. For each species, relevant morphological and morphometric data are provided, such as the host(s), site(s) of infection within the host and sampling state. A key for the identification of 13 genera of tailed Myxobolidae is also included.

Evidence of the American Myxobolus dechtiari was introduced along with its host Lepomis gibbosus in Europe: Molecular and histological data.

The American pumpkinseed Lepomis gibbosus, was introduced to Europe more than one hundred years ago. Currently it is a common fish in European freshwaters but relatively few specific parasites infect this fish in this new habitat. In Europe only a single species, Myxobolus dechtiari seems to represent the American myxosporean fauna of centrarchid fishes. M. dechtiari was found in both Portugal and Hungary. This species forms plasmodia with elongated shape inside the cartilaginous rays of gill filaments. In the advanced stage of infection, after disruption of plasmodia, small groups of myxospores remain enclosed in the cartilaginous gill rays causing distortions in the filaments. Myxospores were ellipsoidal in frontal view and lemon-shape in sutural, length 12.5 ± 0.46 (12-13.4) µm, width 10 ± 0.37 (9.6-10.4) µm, and thickness 7.4 ± 0.37 (7-8) µm; the polar capsules were pyriform, equal in size, length 5.6 ± 0.21 (5.3-6) µm, width 3.2 ± 0.16 (3-3.6) µm; Seven to eight polar tube coils were arranged perpendicularly to the capsule length. There was a small, round, 0.4 ± 0.1 (0.3-05) (N = 50) intercapsular appendix in the spores. The small subunit ribosomal DNA (ssrDNA) of M. dechtiari differed from other myxozoans sequenced to date. Phylogenetic analysis of the ssrDNA gene sequence placed this species in a clade including actinospores and Myxobolus species: Raabeia type1, Triactinomyxon sp., and Myxobolus osburni infecting the same host fish. The focus of our study was to prove that the pumpkinseed, a fish originated from North-America introduced one of its myxosporean parasite to Europe. Emphasis was put on to demonstrate the unique feature of this parasite causing infection in the cartilaginous gill rays.

Fish-borne nematodiases in South America: neglected emerging diseases.

Fish-borne zoonotic nematodes may infect humans when fish or squid are ingested raw or inadequately cooked. Human infections may have serious consequences, including the unexpected deaths of infected people. This kind of disease is poorly known in general, and the characteristics of such infections in South American countries as a whole have never been assessed. In this paper the present status of fish-borne nematodiases in humans in South American countries is characterized. Potentially zoonotic nematode species are very common in both freshwater and marine fish in South America. Reports of human infections have only been found in some countries, and their incidence (especially with anisakids and Gnathostoma spp.) varies from country to country. Apparently they are more abundant in countries with strong traditions of eating raw fish, and are more frequent on the western coast of South America. So far fish-borne nematodes have been reported in Argentina, Brazil, Chile, Colombia, Ecuador and Peru. In recent years, cases of human infection have appeared in probably underestimated numbers. People need to be clearly informed about risky feeding habits, and physicians need to learn more about zoonotic diseases.

A note on the infection of Scomberomorus brasiliensis (Osteichthyes, Scombridae) by Kudoa sp. (Myxozoa: Multivalvulida).

The infection of Scomberomorus brasiliensis by the myxozoan Kudoa sp. is reported. The parasites formed plasmodiae inside the skeletal muscle fibres. The spores were quadrate in apical view and bell-like shaped in lateral view, containing four equally sized more or less rounded polar capsules. No detrimental effects were observed in the host, namely muscle liquefaction. The importance of these parasites is discussed.

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.

A checklist of new species of Henneguya Thélohan, 1892 (Myxozoa: Myxosporea, Myxobolidae) described between 2002 and 2012.

A checklist of the new species of Henneguya described since 2002 (43 species) is presented. Included are the main features of each species, the type-host, the type-locality and the original references. In addition, accession numbers to sequences in GenBank are indicated whenever possible.

Comparison of the Myxobolus fauna of common barbel from Hungary and Iberian barbel from Portugal.

We compared Myxobolus infection of common barbel Barbus barbus from the Danube River in Hungary with that in Iberian barbel Luciobarbus bocagei from the Este River in Portugal. In Hungary, we recorded 5 known Myxobolus species (M. branchialis, M. caudatus, M. musculi, M. squamae, and M. tauricus) and described M. branchilateralis sp. n. In Portugal we recorded 6 Myxobolus species (M. branchialis, M. branchilateralis sp. n., M. cutanei, M. musculi, M. pfeifferi, and M. tauricus). Species found in the 2 habitats had similar spore morphology and only slight differences were observed in spore shape or measurements. All species showed a specific tissue tropism and had a definite site selection. M. branchialis was recorded from the lamellae of the gills, large plasmodia of M. branchilateralis sp. n. developed at both sides of hemibranchia, M. squamae infected the scales, plasmodia of M. caudatus infected the scales and the fins, and M. tauricus were found in the fins and pin bones. In the muscle, 3 species, M. musculi, M. pfeifferi and M. tauricus were found; however they were found in distinct locations. Plasmodia of M. musculi developed intracellularly in muscle cells, plasmodia of M. tauricus were found in the dense connective tissue of the pin bones, whereas M. pfeifferi formed plasmodia in the connective tissue of the intramuscular septa. This latter species was often found in the cartilaginous gill arch as well. Comparative morphological and phylogenetic studies, as well as 18S rDNA sequences, revealed differences between the Myxobolus fauna of the 2 barbel species originating from different geographic regions.

Synopsis of the species of Myxidium Bütschli, 1882 (Myxozoa: Myxosporea: Bivalvulida).

A synopsis of the species of Myxidium Bütschli, 1882 (Myxozoa: Myxosporea: Bivalvulida) is presented. It includes a total of 232 nominal species, whose principal morphological and morphometric characteristics, site of infection within the host, and original hosts and locality are indicated in a tabulated format. A diagrammatic illustration of a spore of most of the species is also provided.

Henneguya corruscans n. sp. (Myxozoa, Myxosporea, Myxobolidae), a parasite of Pseudoplatystoma corruscans (Osteichthyes, Pimelodidae) from the Paraná River, Brazil: a morphological and morphometric study.

This paper describes the parasite Henneguya corruscans n. sp. which infects the gills of Pseudoplatystoma corruscans Spix and Agassiz, 1829 found in the Paraná River, Brazil. The parasites belong to the interlamellar-epithelial type as defined by Molnár (2002) [Molnár, K., 2002. Site preference of fish myxosporeans in the gills. Dis. Aquat. Org. 48, 197-207]. The spores examined had thin, smooth walls with symmetric valves; the total length of the spores was 27.6 (25-29)mum. The spore body was ellipsoidal in frontal view and biconvex in lateral view and they measured 14.3 (13-15)mum long by 5mum wide and 4mum in thickness. The polar capsules were small and elongated, equally sized, with a rounded posterior extremity and tapering anteriorly, and they corresponded more or less the half the length of the spore body; they were 6.8 (6-7)mum long by 2mum wide, and the polar filament formed 5-6 coils obliquely to the axis of the polar capsule. The tail was 13.7 (12-15)mum long and bifurcated shortly after the end of the spore body. The importance of the infection for the farming of P. corruscans is discussed.

Myxobolus sp. can cause in vivo myoliquefaction in the host Paralichthys orbignyanus (Osteichthyes, Paralichthydae).

We found intense myoliquefaction in vivo among specimens of wild and farmed South American flatfish Paralichthys orbignyanus Valenciennes, 1839. The soft flesh condition was attributed to Myxobolus sp. since the fish were not infected by myxosporeans which are usually associated with this condition (Kudoa spp.), and other causes (bacteria, fungi) were not found. The histopathology of the infection is described.

Myxobolus platanus n. sp. (Myxosporea, Myxobolidae), a parasite of Mugil platanus Günther, 1880 (Osteichthyes, Mugilidae) from Lagoa dos Patos, RS, Brazil

Myxobolus platanus n. sp. infecting the spleen of Mugil platanus Günther, 1880 (Osteichthyes, Mugilidae) from Lagoa dos Patos, Brazil is described The parasites formed round or slightly oval whitish plasmodia (about 0.05-0.1mm in diameter) on the surface of the organ. The spores were round in frontal view and oval in lateral view, 10.7µm (10-11) long, 10.8µm (10-11) wide and 5µm thick, and presented four sutural marks along the sutural edge. The polar capsules, equal in size, were prominent, surpassing the mid-length of the spore, and were oval with the posterior extremity rounded, and converging with their anteriorly tapered ends. They were 7.7µm (7-8) long and 3.8µm (3.5-4) wide. A small intercapsular appendix was present. The polar filament formed five to six coils obliquely placed to the axis of the polar capsule. No mucous envelope or distinct iodinophilous vacuole were found

Descreve-se Myxobolus platanus n. sp. infectando o baço de Mugil platanus Günther, 1880 (Osteichthyes, Mugilidae) da Lagoa dos Patos, Brasil. Os parasitas formavam plasmódios brancos redondos ou ligeiramente ovais (diâmetro de cerca de 0,05-0,1mm) à superfície do órgão. Os esporos eram circulares em observação frontal e ovais em obervação lateral, medindo, em média, 10,7µm (10-11) de comprimento, 10,8µm (10-11) de largura e 5µm de espessura, e tinham quatro marcas suturais ao longo da linha de sutura. As cápsulas polares eram grandes e do mesmo tamanho ultrapassando a zona média do esporo. Eram de forma oval, tendo a extremidade posterior arredondada, e convergiam pelas extremidades anteriores afiladas, medindo 7,7µm (7-8) de comprimento por 3,8µm (3,5-4) de largura. Um pequeno apêndice intercapsular estava presente. O filamento polar formava cinco a seis dobras colocadas obliquamente em relação ao eixo da cápsula. Não havia envelope mucígeno nem vacúolo iodofílico

Ecology of Clinostomum complanatum Rudolphi, 1814 (Trematoda: Clinostomidae) infecting fish from the floodplain of the high Paraná River, Brazil.

The prevalence of Clinostomum complanatum Rudolphi, 1814 (Digenea, Clinostomidae) in fishes Loricariichthys platymetopon, Parauchenipterus galeatus and Hoplosternum littorale, which are second intermediate hosts, was studied at the floodplain of the high Paraná River, Brazil. Season (alternation flood-drought), habitat (lentic and semi-lotic), and sex were not related to its prevalence. For L. platymetopon, the immature and smaller fish had the lowest prevalence, whilst the opposite was observed for P. galeatus and H. littorale. This suggests that the probability of being predated is unchanged by parasitism for L. platymetopon; thus, a cumulative effect of repeated infections is observed; for the two other species, the highest parasitised fish may have higher predation mortality rates. While H. littorale is the preferred item in birds' diet, L. platymetopon is the most abundant fish species and has the highest C. complanatum prevalence, which makes it the most likely path of transmission to the bird, the definitive hosts of C. complanatum.

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 a new synactinomyxon type from the River Sousa, Portugal.

Actinospore infection of oligochaetes collected from the mud of 2 freshwater biotopes in Portugal was studied. Using the 'cell-well plate method', a new synactinomyxon type was found in 2 specimens (1.3%) of the examined Tubifex tubifex oligochaetes from the River Sousa north of Porto, Portugal. In Criodrilus lacuum and Dero digitata specimens collected from the same river, no actinosporeans were released during the 12 wk observation period. Infected oligochaetes were only found immediately post-collection, and no further actinosporean release was recorded in Tubifex specimens kept alive for several weeks. Actinospore infection showed high intensity in oligochaetes in both positive cases. No actinosporean stages of myxosporeans have as yet been described from Portugal. On the basis of spore morphology and 18S rDNA sequence data, the synactinomyxon type presented in this paper differs from those already known and described in the literature.

Myxobolus insignis sp. n. (Myxozoa, Myxosporea, Myxobolidae), a parasite of the Amazonian teleost fish Semaprochilodus insignis (Osteichthyes, Prochilodontidae).

A new myxosporean species is described from the fish Semaprochilodus insignis captured from the Amazon River, near Manaus. Myxobolus insignis sp. n. was located in the gills of the host forming plasmodia inside the secondary gill lamellae. The spores had a thick wall (1.5-2 microm) all around their body, and the valves were symmetrical and smooth. The spores were a little longer than wide, with rounded extremities, in frontal view, and oval in lateral view. They were 14.5 (14-15) microm long by 11.3 (11-12) microm wide and 7.8 (7-8) microm thick. Some spores showed the presence of a triangular thickening of the internal face of the wall near the posterior end of the polar capsules. This thickening could occur in one of the sides of the spore or in both sides. The polar capsules were large and equal in size surpassing the midlength of the spore. They were oval with the posterior extremity rounded, and converging anteriorly with tapered ends. They were 7.6 (7-8) microm long by 4.2 (3-5) microm wide, and the polar filament formed 6 coils slightly obliquely to the axis of the polar capsule. An intercapsular appendix was present. There was no mucous envelope or distinct iodinophilous vacuole.

Synopsis of the species of Myxobolus Butschli, 1882 (Myxozoa: Myxosporea: Myxobolidae).

A synopsis of 744 nominal species of Myxobolus Butschli, 1882 (Myxozoa, Myxosporea, Myxobolidae) is presented. For each species, the relevant morphometric and morphological data are indicated, as well as the host(s), site(s) of infection within the host and type-locality.

Myxobolus insignis sp. n. (Myxozoa, Myxosporea, Myxobolidae), a parasite of the Amazonian teleost fish Semaprochilodus insignis (Osteichthyes, Prochilodontidae)

A new myxosporean species is described from the fish Semaprochilodus insignis captured from the Amazon River, near Manaus. Myxobolus insignis sp. n. was located in the gills of the host forming plasmodia inside the secondary gill lamellae. The spores had a thick wall (1.5-2 µm) all around their body, and the valves were symmetrical and smooth. The spores were a little longer than wide, with rounded extremities, in frontal view, and oval in lateral view. They were 14.5 (14-15) µm long by 11.3 (11-12) µm wide and 7.8 (7-8) µm thick. Some spores showed the presence of a triangular thickening of the internal face of the wall near the posterior end of the polar capsules. This thickening could occur in one of the sides of the spore or in both sides. The polar capsules were large and equal in size surpassing the midlength of the spore. They were oval with the posterior extremity rounded, and converging anteriorly with tapered ends. They were 7.6 (7-8) µm long by 4.2 (3-5) µm wide, and the polar filament formed 6 coils slightly obliquely to the axis of the polar capsule. An intercapsular appendix was present. There was no mucous envelope or distinct iodinophilous vacuole.

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

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

Henneguya schizodon n. sp. (Myxozoa, Myxobolidae), a parasite of the Amazonian teleost fish Schizodon fasciatus (Characiformes, Anostomidae).

A new histozoic species of myxosporean (Henneguya schizodon n. sp.) is described from the Amazon River teleost fish Schizodon fasciatus Spix & Agassiz, 1892 (Characiformes, Anostomidae). The plasmodia, which showed asynchronous development, were located in the kidney of the host. The spore body was ellipsoidal and was 13.1 (12-14) micron long by 3.3 (3-4) micron wide. The total length of the spore was 28.9 (27-30) micron, and each value had a caudal process measuring 16.3 (15-17) micron. The polar capsules were 5.4 (5-6) micron long by 1.3 (1-1.5) micron wide, and each had a polar filament with 8-10 coils. The characteristics of the species were compared with nearly all the species described so far, including all the species reported from South American fishes. This comparison allows to consider the materials as a new species, and the name Henneguya schizodon n. sp. is proposed.