Volume 56, Issue 3

Two new coccidian species (Protozoa, Apicomplexa, Eimeriidae) are reported from the saffron finch Sicalis flaveola Linnaeus, 1766, a very common species in South America. Isospora cetasiensis sp. nov. oocysts are subspherical to ellipsoidal, 23.1 × 21.6 μm, with smooth, bilayered wall, ∼1.0 μm. Micropyle, oocyst residuum and polar granule are absent. Sporocysts are ovoidal, 15.1 × 10.9 μm. Stieda body is knob-like and substieda body is rounded. Sporocyst residuum is composed of many scattered granules and spherules of different sizes. Sporozoites are vermiform with one refractile body and a nucleus. Isospora sicalisi sp. nov. oocysts are subspherical to ellipsoidal, 27.5 × 25.2 μm, with a smooth, bilayered wall, ∼1.1 μm. Micropyle, oocyst residuum and polar granule are absent. Sporocysts are ellipsoidal, 17.2 × 11.7 μm. Stieda body is knob-like and substieda body is trapezoidal. Sporocyst residuum is composed of scattered granules and spherules of different sizes. Sporozoites are vermiform with one refractile body and a nucleus.

Neospora caninum is transmitted from a cow to its foetus by vertical transmission and the timing of infection in gestation is an important factor in determining the disease outcome. Few studies have explored the role of the placenta in the outcome of N. caninum infection during pregnancy. Here, we described the N. caninum presence, parasite load, local immune response, and histopathological lesions at the materno-foetal interface after infection of BALB/c mice at early and late stages of gestation. In mice infected at early gestation, N. caninum DNA was detected in foetoplacentary units 7 days post-infection (PI) and in the placenta, but not in viable foetuses on day 14 PI, indicating that the parasite was multiplying primarily in the placental tissues without reaching the foetus. Moreover, parasite DNA was detected in resorptions, suggesting that foetal death could be a consequence of infection. An increase in IFN-γ, TNF-α and IL-10 expression was observed in N. caninum PCR-positive placentas, which could favour N. caninum foetal transmission and be harmful to both the placenta and the foetus. Histopathological analysis revealed necrosis affecting both the maternal and foetal sides of the placenta. At late gestation, transmission occurred rapidly following infection (day 3 PI), but parasite were rarely found. In addition, an increase in cytokine expression was observed in spleen and placental tissues from infected animals, while a downregulation in IL-4 expression was only observed in the spleen. Finally, necrosis in the placenta was limited to the maternal side, suggesting that the parasite is mainly multiplying in the placental tissue at this stage. Thus, the results of the present study indicate that the placenta may be actively involved in N. caninum pathogenesis.

A 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.

Of the 850 known Myxobolus spp., 89 named species have DNA (in most cases 18S rDNA) sequences deposited in the Genbank. Only a part of the deposited sequences represent well identified samples collected from adequate organs of the original hosts. Some of the samples were collected from additional hosts or from fishes genetically far standing from the type-host. In the paper, reliability of sequences of some best known Myxobolus spp., deposited in the Genbank from freshwater fishes of Eurasia’s Palaearctic Region, are surveyed. Genbank sequences are classified into three groups. Sequences obtained from morphologically well characterised Myxobolus spp., which were collected from the type hosts, compose the group of valid sequences. To the group of probable valid sequences belong samples from spores morphologically corresponding to the original description, but collected from fishes closely related to the type-host; while sequences obtained from hosts genetically far standing from the type-hosts represent the category of the un-valid group.

A new species of Kritskyia Kohn, 1990 (Monogenea, Dactylogyridae, Ancyrocephalinae) is described from the urinary bladder of Salminus brasiliensis (Cuvier, 1816) (Characiformes, Characidae) from the Cuiabá River, the Pantanal wetlands, Brazil. The male copulatory apparatus of the new species differs from those of other species of the genus by the presence of a bipartite accessory piece (distally and proximally linked), one part grooved, serving as guide for distal portion of the MCO. Moreover, the vagina of the new species differs from those of congeners by possessing distal digitiform processes.

Monocotyle was proposed by Taschenberg (1878) to accommodate M. myliobatis Taschenberg, 1878 from the gills of Myliobatis aquila (Linnaeus) caught at the Aquarium of the Zoological Station of Naples (Italy). There have been three descriptions of this species: the original one by Taschenberg (1878) and two which are incomplete by Perugia and Parona (1890) and Palombi (1942). Illustrations by these authors are poor and sometimes conflicting. We have rediscovered M. myliobatis on the gills of the type host Myliobatis aquila caught near Algiers, Tamentfoust (36°47′N, 3°12′E) (Algeria). We provide new illustrations of this monogenean, based on new specimens. We also redescribe the anatomy, with special attention to the male and female reproductive systems, and we provide additional data regarding the morphology, the number and arrangement of the septal sclerites of the haptor and the haptoral marginal papillae. We indicate the similarity between Monocotyle myliobatis and Monocotyle sp. Euzet et Maillard, 1967 collected from Pteromyleus bovinus, Geoffroy Saint Hillaire (Elasmobranchii, Myliobatidae) by J. Cadenat off Dakar (Senegal).

Pseudoleptobothrium christisoni sp. nov. is described from the dermal denticles of the dorsal skin surface of a single female Rhinobatos annulatus collected off Cape Agulhas, South Africa and destined for public exhibition at the Two Oceans Aquarium in Cape Town. This new species differs from the only other species in the genus, P. aptychotremae Young, 1967, primarily by the morphology of the male copulatory tract. The distal portion of the male copulatory tract is wide and bears muscular papillae internally and externally. In addition, the area of ventral tegument near the vaginal pore has several parallel ridges which appear to serve as the initial attachment site for a bipartite spermatophore. The formation of the spermatophore in P. christisoni is discussed. The generic diagnosis of Pseudoleptobothrium is revised to accommodate P. christisoni and a partial redescription of P. aptychotremae is provided to include characters originally not described or described incorrectly.

A new species Polylabris bengalensis (Monogenea, Microcotylidae) is described from the gills of the siganid fishes, Siganus javus and S. oramin from the coast of Visakhapatnam, Bay of Bengal, India. It most closely resembles P. mamaevi but differs in having unequal caeca terminating at different levels in the haptor, in the follicular testis forming a compact mass, in the presence of a thick layer of concentric muscles surrounding the genital atrium and in the terminal part of the male copulatory organ not recurved. The validity of various species of Polylabris recorded from siganids from different geographical regions is discussed.

We report a new species of Allopodocotyle Pritchard, 1966 from the intestine of two species of Serranidae, Cromileptes altivelis and Epinephelus fuscoguttatus, from the southern Great Barrier Reef. Despite the examination of eight other species of Epinephelus from the same region this species appears anomalous in its distribution in one species of Epinephelus and the single species of Cromileptes. Molecular phylogenetic studies of the Epinephelinae suggest, however, that these two species are closely related so that the host specificity demonstrated by this species is actually stenoxenic (phylogenetically related hosts) rather than euryxenic.

Hypocreadium caputvadum sp. nov. (Digenea, Lepocreadiidae) is described from the intestine of Balistes capriscus Gmelin collected from the Gulf of Gabès (Tunisia) in the southern Mediterranean Sea. This new species can be distinguished by a combination of characteristics shared by no other described species of Hypocreadium Ozaki, 1936. These characteristics include the presence of a distinct anterior notch, the follicular vitellarium confluent in the forebody, the presence of a muscular sphincter at the level of the anterior third of the metraterm and the size and the position of the cirrus-sac.

Neolepidapedoides subantarcticus sp. nov. (Digenea, Lepocreadiidae) is reported from the intestine, mainly the jejunum, of fishes in the eastern mouth of the Beagle Channel and in the harbour of Ushuaia in the Beagle Channel (Tierra del Fuego, Argentina) at a depth 7–30 m. The typical host is Patagonotothen longipes, other hosts are P. tessellata, P. brevicauda and Champsocephalus esox. The male terminal genitalia indicates that the new species belongs to the genus Neolepidapedoides (Lepocreadiidae, Lepocreadiinae). The most important taxonomic features are the presence of eye-spots, the spined tegument, the “Opechona-type” cirrus-sac, the external seminal vesicle free in the parenchyma, the gonads arranged in tandem, the vitelline follicles extending from the level of the oesophagus in the forebody to the posterior end of the body and an I-shaped excretory vesicle reaching to the intestinal bifurcation and the absence of a pseudoesophagus. Ten previously described species differ from the N. subantarcticus sp. nov. mainly in the extent of the vitelline fields and length of the excretory vesicle which reaches into forebody.

A new species of parasitic nematode, Hysterothylacium spirale sp. nov. (Ascaridoidea, Anisakidae), is described based on specimens collected from the intestine and pyloric caeca of the silvery john dory Zenopsis conchifer (Lowe) (Zeiformes, Zeidae), from the Argentinean Shelf (35°05′–40°46′S, 53°03′–58°07′W). Among the 66 valid species described so far in the genus, the new species most closely resembles H. zenis (Baylis, 1929). Both species, apparently specific for fishes of the family Zeidae, share the shape of the dorsal lip, the long expanded lateral alae originating from subventral interlabia and the ornamentation of the tail tip, as well as general morphometry. The combination of these shared features distinguishes both species from all congeners so far known. However, the new species is distinguishable from H. zenis by having shorter interlabia, and consequently the lateral alae originating more posteriorly, shorter spicules, a smaller number of postcloacal papillae and the presence of two pairs of double postcloacal papillae.

The acuarioid nematode Echinuria skrjabiniensis Efimov in Skryabin, Sobolev et Ivashkin, 1965 was found in Calidris bairdii and C. fuscicollis (Aves, Scolopacidae) examined from several locations from Patagonia, Argentina. These constitute new host records as well as the first record of this parasite species in South America. Using both light and scanning electron microscopies, new morphological details are provided, including the description of the left spicule and the number and the arrangement of male caudal papillae. The taxonomic history of the species is summarized, corroborating its correct spelling and valid name.

Information on parasites of vertebrates living in terrestrial ecosystems as monitoring tools for heavy metal environmental pollution is scarce. The present study evaluates the potential suitability of the models Rattus rattus/Moniliformis moniliformis and Mus domesticus/Rodentolepis microstoma as promising bioindicator systems for cadmium and lead pollutions under natural conditions. The highest level of cadmium was found in one specimen of M. moniliformis (335.2 ng g−1 wet weight) and the average concentration of Cd in the acanthocephalan was significantly higher than values found in R. rattus liver and kidney tissues. The maximum concentration of lead occurred in one specimen of R. microstoma (567.4 ng g−1 wet weight) and the average concentration of Pb in the cestode was significantly higher than values found in M. domesticus liver, kidney and muscle tissues. The present results allow proposing both models as promising biomonitoring systems to evaluate environmental cadmium pollution (mainly R. rattus/M. moniliformis) and lead contamination (especially M. domesticus/R. microstoma) in terrestrial nonurban habitats.

A new monobasic genus of parasitic mites, Phalarophilus fulicarius gen. nov., sp. nov. (Acariformes, Syringophilidae) is described from feather quills of Phalaropus fulicarius (Linnaeus) (Charadriiformes, Scolopacidae) from USA. Females of the new genus differs from those of the genus Bochkovia Skoracki et OConnor, by having the rounded posteriorly stylophore, edentate movable cheliceral digits, propodonotal setae arranged 2-1-1-2, thin and smooth dorsal setae of the idiosoma, smooth dorsal setae of legs I and II, and by the presence of setae vsI; males are distinguished by the presence of the propodonotal setae arranged 2-1-1-1-1. Additionally, two new syringophilid species recorded from aquatic birds in North America and three new host associations of these mites are recovered.