Light and scanning electron microscopy of Myxobolus porofilus sp. n. (Myxosporea: Myxobolidae) infecting the visceral cavity of Prochilodus lineatus (Pisces: Characiformes: Prochilodontidae) cultivated in Brazil

Myxobolus porofilus sp. n. is described infecting the visceral cavity of Prochilodus lineatus (Valenciennes, 1836) cultivated in S?o Paulo State, Brazil. The plasmodial form of the parasite is 3-5 mm in length and appeared compressed between the wall of the visceral cavity and the pyloric caecum, reposing on this organ. The spores are small (length 5.7 +/- 0.3 microm, width 4.8 +/- 0.2 microm; mean +/- SD) and round to elliptical in frontal view. The valve surfaces are smooth and have sutural folds. The polar capsules are ovoid, small (length 1.6 +/- 0.1 microm, width 1.1 +/- 0.1 microm) and equal in size. The polar filaments have three turns aligned perpendicularly to the longitudinal axis of the capsule. A conspicuous polar filament pore is arranged at the anterior end of the spore. The only reaction observed upon histological analysis was the presence of a capsule of connective tissue surrounding the plasmodia. This is the first report of a myxosporean parasite in the Prochilodontidae.     

Myxobolus buckei sp. n. (Myxozoa), a new pathogenic parasite from the spinal column of three cyprinid fishes from the United Kingdom

Myxobolus buckei sp. n. is described from the spinal column of Leuciscus cephalus (L.), Rutilus rutilus (L.) and Abramis brama (L.) from freshwater rivers in the North of England. The plasmodia develop within the remnants of the embryonic notochord in the intervertebral spaces. The spores are large, measuring (in microm) 14.0 +/- 0.7 x 11.5 +/- 0.6 (mean +/- SD), smooth, round to ellipsoid in valvular view with several sutural edge markings. The polar capsules are pyriform and of equal size, measuring 7.5 +/- 0.5 x 4.2 +/- 0.2 (mean +/- SD), with 11-12 turns of the polar filament arranged perpendicularly to the longitudinal axis of the polar capsule. The parasite has a large intercapsular appendix and large iodinophorous vacuole. The parasite can be differentiated from all known species of Myxobolus Bütschli, 1882 by a combination of the morphological characters defined. Infected fish show marked longitudinal compression of the body compared to uninfected individuals of the same year class, a feature which is pathognomonic for the disease. Histologically, host responses ranged from mild hypertrophy of the zygapophyseal process and expansion of the intervertebral membrane to complete hypertrophy and fusion of the vertebrae. Prominent notochord is present in the intervertebral spaces of infected fish and sporogony of the parasite leads to a vigorous focal inflammatory response involving proliferating fibroblast and osteogenic cells. The parasite causes a radial expansion of the centra and extensive dorsal and ventral outgrowths of the vertebrae leading to compression of the spinal cord and blood vessels running through the neural and haemal spines respectively. The parasite is considered highly pathogenic to juvenile cyprinids.     

Ellipsomyxa gobii gen. et sp. n. (Myxozoa: Ceratomyxidae) in the common goby Pomatoschistus microps (Teleostei: Gobiidae) from Denmark

A new myxosporean species Ellipsomyxa gobii gen. et sp. n. is described from the common goby Pomatoschistus microps (Kr?yer) (Perciformes, Gobiidae). Plasmodia with long branched pseudopodia in the gallbladder develop to subspherical bisporous plasmodia. The myxospores were found in the gallbladder, and the hepatic and bile ducts. The new genus is characterised by the morphology of the myxospores. The myxospores have smooth thin valves elongated in the direction perpendicular to the plane of the straight central transverse indistinct sutural line. The two spherical polar capsules open some distance from the sutural line on opposite sides. The new genus thereby differs from Leptotheca Thélohan, 1895. Ellipsomyxa gobii is tentatively placed in the Ceratomyxidae.     

Phylogeny of Coccomyxa (Myxosporea: Myxidiidae) spp. with the description of a new species from Bathygobius cyclopterus (Gobiidae) in the northern Red Sea

Two species of Coccomyxa Léger et Hesse, 1907, one of the least studied myxosporean genera, are reported from shallow coastal waters in the Gulf of Eilat, Red Sea, Israel. A new species, Coccomyxajirilomi sp. n. is described from the spotted frillgoby Bathygobius cyclopterus (Valenciennes) (Gobiidae). It forms polysporous plasmodia that invade the liver and form packed clusters inside the bile ductules. Plasmodia also occur in the bile ducts and gall bladder of the host, attached to the epithelial lining or free floating in the bile. Infected hepatic bile ductules packed with plasmodia were partially occluded, with evidence of cholestasis, periductular fibrosis and pericholangitis. The mature spore is ellipsoid, has smooth valves and contains a single polar capsule with the polar filament arranged in 4-5 oblique coils. Spore dimensions are 9.0-11.3 x 5.0-7.0 microm. A second species, Coccomyxa sp., with smaller 7.6-9.6 x 4.2-5.2 microm and more delicate spores, was found in the gall bladder of the rippled rockskipper, Istiblennius edentulus (Forster et Schneider) (Blenniidae). The small subunit (SSU) rDNA sequence analysis of both Coccomyxa species suggests that they are closely related to members of the genera Myxidium, Zschokkella and Auerbachia, whose members infect the gall bladder of marine fish.     

Fine structure of Henneguya pilosa sp. n. (Myxozoa: Myxosporea), parasite of Serrasalmus altuvei (Characidae), in Brazil

Henneguya pilosa sp. n., a new species of myxosporean from the gill filaments of the white piranha, Serrasalmus altuvei Ramirez, 1965 (Characidae), a freshwater teleost fish collected in the Zoological Garden of the city of Teresina (Piauí), Brazil, is described from light and transmission electron microscope observations. This myxosporean produced small plasmodia (up to 0.2 mm in diameter), each one containing all life-cycle stages of the parasite, including numerous spores. The spores, laterally compressed, averaged 54.2 (52.3-56.0) microm in total length and consisted of two unequal valves adhering together along the suture line and two caudal processes. The spore body measured 21.1 (20.0-23.1) microm in length, 5.9 (5.5-6.3) microm in width, and 2.2 (1.9-2.6) microm in thickness. The two equal ellipsoidal polar capsules of 7.4 (7.1-7.6) microm long and 1.2 (1.0-1.3) microm wide possessed a polar filament with 11-12 (rarely 13) turns. All surfaces of the spores were covered with a tightly adherent complex network of numerous densely ramified granulo-fibrillar masses, the longest measuring 1.5 microm long, observed around the caudal processes. The prevalence of infection was 30%. The taxonomic affinities of this parasite with other of the same genus in freshwater South American fish species are discussed.     

In vitro culture of Bovicola limbata Gervais, 1844 (Mallophaga), study of its survival and life cycle

Bovicola limbata Gervais, 1844 has been cultured in vitro at 35 +/- 1.5 degrees and 75 +/- 5% R.H. using scrapings from goatskin and host hair as food. In these conditions its complete life cycle has been obtained. New data are given on the biology of this species: maximum, minimum and average number of eggs laid per female; reabsorbed, embryonal, hatched and unhatched eggs; percentage of specimens that reached the second, third and adult instars; mortality percentage in the first, second and third instars.     

Ultrastructural characteristics of Nematopsis sp. oocysts (Apicomplexa: Porosporidae), a parasite of the clam Meretrix meretrix (Veneridae) from the Arabian Gulf, Saudi Arabia

This paper describes the fine structure of oocysts of Nematopsis sp. (Apicomplexa, Porosporidae) found in the abductor muscles of seawater clams, Meretrix meretrix (Linnaeus, 1758) (Veneridae), collected near the city of Dammam (6 degrees 17'0"N, 50 degrees 12'0"E) in the Arabian Gulf off the coast of Saudi Arabia. Oocysts of an ellipsoidal shape were found among myofibrils of the abductor muscles of infected clams. Each oocyst is composed of an oocyst wall surrounding a single uninucleate vermiform sporozoite located in the lumen of the oocyst wall. The thin oocyst wall (0.70-0.85 microm thick) is composed of homogenous electron-lucent material formed by three layers of equal-thickness. The oocyst wall contains a plano-convex opercular-like structure about 2.5 microm in diameter and 0.75-0.90 microm thick, composed of a homogenous material with moderate electron density. The oocyst is of an ellipsoidal shape and is 15.6 +/- 0.6 microm long and 11.1 +/- 0.7 microm wide. Externally, the oocyst wall is surrounded by a complex dense network of numerous anastomosed microfibrils, which are attached to the oocyst wall, forming 2-3 layers and extending towards the periphery, at some points penetrating amongst the host cells. The myofibrils in some cases show evident aspects of lysis as a consequence of the appearance of lysosome-like vesicles. Lacking knowledge of a complete life cycle and/or molecular data precluded the conclusive identification of this species.     

Henneguya cynoscioni sp. n. (Myxosporea: Bivalvulida), an agent of severe cardiac lesions in the spotted seatrout, Cynoscion nebulosus (Teleostei: Sciaenidae)

A new myxosporean species, Henneguya cynoscioni sp. n., is described from the spotted seatrout, Cynoscion nebulosus (Cuvier) (Sciaenidae) as a causative agent of cardiac henneguyosis. This new myxosporean species is characterized by the morphology of spores and the sequence of SSU rDNA. Examination of 227 spotted seatrout from four South Carolina estuaries in 2008-2010 revealed a 33.5% total prevalence of H. cynoscioni. Henneguya cynoscioni produces lesions in the bulbus arteriosus, its specific site of infection. The severity of lesions and their impact on the bulbus arteriosus is proportional to the number of plasmodial stages developing in this segment of the heart, being most pronounced in host reaction directed against spores liberated from plasmodia.     

Redescription of Eimeria dorcadis Mantovani, 1966 (Apicomplexa: Eimeriidae) from the dorcas gazelle (Gazella dorcas) in Saudi Arabia

Eimeria dorcadis Mantovani, 1966 is redescribed from dorcas gazelle (Gazella dorcas (L.)) from Saudi Arabia. Oocysts were detected in 7 out of 22 faecal samples (32%) using floatation method. The sporulated oocysts are cylindrical, slightly flattened at the micropylar pole, measure in average 32 x 19 microm (27-36 x 16-24 microm), length/width ratio being 1.7 (1.5-2.1). Oocyst wall is 1.2 microm thick, smooth, double-layered; outer layer is slightly thicker, light blue in colour; inner layer brownish, with micropyle in the inner layer and apparently continual outer one, measures 2.2 microm, but lacks a micropylar cap. The sporocyst elongate-ellipsoidal, measures 14 x 8 microm (12-17 x 6-9 microm), length/width ratio being 1.8, with sporocyst residuum as circular compact, coarse, refractile granules. Stieda body is present, while substieda body is absent. Sporozoites banana-shaped, measure 11 x 2.5 microm, each with a large spheroidal refractile body at the wider pole. Sporulation time is 2-3 days at 25 +/- 2 degrees C.     

The endogenous development, described by light and electron microscopy, of Eimeria jamescooki sp. n. (Apicomplexa: Eimeriidae) from the skink Cryptoblepharus virgatus

Eimeria jamescooki sp. n. was recovered from the skink Cryptoblepharus virgatus (Garman) found on the grounds of James Cook University, Townsville (type locality), North Queensland, Australia. Oocysts were 17.5-25.0 (22.1 +/- 1.9) x 15-22.5 (17.7 +/- 1.6) microm and sporocysts 6.25-10.0 (7.9 +/- 1.15) x 3.75-6.25 (5.3 +/- 1.0) microm in size. Endogenous stages are described from histological material examined by light microscope and by transmission electron microscope. Both merogony stages and gamonts were found to develop in the cytoplasm of the anterior gut mucosal epithelium. Meront progeny were comprised of 10 to 21 merozoites. Premature macrogamonts were elongate; some host cells contained two elongate macrogamonts. Unique to the presently described species were the Golgi "plaques" and an enclosure of tubuli. Mature macrogamonts and young oocysts ranged in size from 14 x 7 to 21 x 11 microm and contained two types of wall-forming bodies, canaliculi and amylopectin granules. Differentiating microgamonts conformed in fine structure with that observed in other eimerians. Their sizes increased from 15.4 x 4.2 to 28 x 8.4 microm while dividing to over 70 nuclei, which formed a corresponding yield of microgametes.     

Caryospora varaniornati sp. n. (Apicomplexa: Eimeriidae) in the Nile monitor, Varanus (Polydaedalus) niloticus species complex

Parasitological examination of two ornate Nile monitors Varanus ornatus (Daudin, 1803) imported from Benin revealed the presence of a new species of Caryospora. Oocysts of Caryospora varaniornati sp. n. are spherical to slightly subspherical, 12.0 (11-12.5) x 11.5 (11-12) microm, without amicropyle and oocyst residuum, and occasionally possessing one small polar granule. Sporocysts are broadly ellipsoidal, 8.8 (8.5-9.5) x 6.7 (6.5-7) microm; a lentil-like Stieda body is present, ca. 0.5 x 1 microm; substieda body not visible. Experimental infection of a closely related host, Varanus niloticus (L.), did not lead to the oocyst excretion despite the fact that one of the experimentally inoculated monitors was immunosuppressed by dexamethasone. Histological examination did not reveal stages of coccidian development. Therefore, it is possible that C. varaniornati is strictly host specific.     

Myxobolus intrachondrealis sp. n. (Myxosporea: Myxobolidae), a parasite of the gill cartilage of the common carp, Cyprinus carpio

A species not identifiable with any of the about 23 Myxobolus species recorded from the common carp so far, was detected in the gills of one- and two-summer-old specimens of the common carp ((Cyprinus carpio L.) cultured in pond farms in Hungary. The strictly tissue-specific plasmodia of the parasite were located, surrounded by hyaline cartilage cells, in the chondrous substance of the terminal parts of the gill arches and in the cartilage structure ventrally connecting the gill arches. The spores of the parasite described as Myxobolus intrachondrealis sp. n. developed in globular or ellipsoidal plasmodia measuring 300-600 microm. By their elongated ellipsoidal shape and similarly elongated polar capsules the spores were well distinguishable from the hitherto described Myxobolus species parasitic in the common carp and also from the cartilage-parasitic Myxobolus species of other fishes.     

Natural infection with two genotypes of Cryptosporidium in red squirrels (Sciurus vulgaris) in Italy

We investigated the genotypes of Cryptosporidium infecting red squirrels (Sciurus vulgaris L.) in two areas of the Western Alps in Italy. Examination of 141 faecal samples from 70 red squirrels revealed oocysts of Cryptosporidium in 17 animals (24.3%). Based on 18S rRNA gene sequencing, two genotypes of Cryptosporidium species were found: 15 squirrels were positive for the Cryptosporidium ferret genotype and 2 for the Cryptosporidium chipmunk genotype I. The occurrence and intensity of Cryptosporidium infection did not differ between the study areas or sex. More than 85% of the positive animals were adults; however no difference was found between Cryptosporidium infection in the juvenile and adult age groups. Oocysts of the Cryptosporidium ferret genotype measured 5.5 +/- 0.3 x 5.2 +/- 0.2 microm (shape index 1.06) and the Cryptosporidium chipmunk genotype I 5.8 +/- 0.3 x 5.4 +/- 0.3 microm (shape index 1.07). Neonatal and adult CD1 and BABL/c mice inoculated with 1 x 10(3) fresh oocysts of both genotypes did not produce detectable infection.     

Studies on the development of the cestode Proteocephalus neglectus La Rue, 1911 (Cestoda: Proteocephalidae) under experimental conditions

A part of the life cycle of Proteocephalus neglectus La Rue, 1911, a parasite of trout, starting from release of eggs from mature parasites into water, to the early phase of development in the definitive host, was studied under experimental conditions. Special regard has been paid to development in the intermediate host, copepod Cyclops strenuus. Some oncospheres in eggs kept in water at 5 and 10 degrees C remained infective for 20-25 days. The percentage of infected copepods depended on the length of their contact with parasite eggs. Cestode larvae (cercoscoleces) were formed in the intermediate host on days 8-10 p.i. at the temperatures of 21-22 degrees C, on days 18-21 at 15 degrees C, on days 24-28 at 10 degrees C, and on days 59-65 at 6 degrees C. Most larvae, including infective cercoscoleces, were localized in the cephalothorax of the intermediate host, particularly in its first segment. This localization did not change during their development. The infectivity of cercoscoleces was verified by experimental infection of Salmo gairdneri fry. The development of the cestode in this definitive host was observed for 17 days after infection at 10 degrees C. The finding of P. neglectus cereoscoleces in fish of the families Cottidae and Cyprinidae on day 2 after experimental infection indicates that these larvae can survive for a short time in atypical fish hosts.     

Neoskrjabinolepis merkushevae sp. n. (Cyclophyllidea: Hymenolepididae), a new cestode from shrews from the Palaearctic region

Neoskrjabinolepis (Neoskrjabinolepidoides) merkushevae sp. n. is described from the shrew Sorex minutus L. (type host) from Belarus. The new species is characterised by rostellar hooks 35-37 microm long, provided with small epiphyseal thickening of the handle; short (35-40 microm) cirrus consisting of a basal part with claw-shaped spines, a parabasal part with thin needle-shaped spines and an unarmed distal part; cirrus-sac slightly passing into median field; and 12-16 eggs per gravid uterus. In addition to the type host and the type locality, the host range of the new species includes Sorex araneus L. and there are geographical records from Bulgaria, Lithuania and North-East Altay (Russia).     

Trilosporoides platessae gen. et sp. n. (Myxozoa: Multivalvulida) in the plaice Pleuronectes platessa (Teleostei: Pleuronectidae) from Denmark

A new myxosporean species, Trilosporoides platessae gen. et sp. n. (Multivalvulida), is described from the gallbladder of the plaice Pleuronectes platessa L. (Pleuronectidae) from Denmark. The myxospore of T. platessae is conical in side view, with a 24 microm long, pointed posterior projection. In apical view, the myxospore (diameter 9.4 microm) is round, trilobed and with three spherical polar capsules arranged peripherally, equidistant and opening peripherally through protruding tips. The polar capsules are of different sizes, one often larger than the others (diameter 3.3 microm vs. 2.5 microm). Apart from the long posterior projection, the myxospore of T. platessae differs from those of the three known species of Trilospora Noble, 1959 and from all genera within the order Multivalvulida Shulman, 1959 in the arrangement of the polar capsules. Trilosporoides platessae may temporarily be placed in the vicinity of the Trilosporidae.