Expression of Hairpin-Enriched Mitochondrial DNA in Two Hairworm Species (Nematomorpha).

Nematomorpha (hairworms) is a phylum of parasitic ecdysozoans, best known for infecting arthropods and guiding their hosts toward water, where the parasite can complete its life cycle. Over 350 species of nematomorphs have been described, yet molecular data for the group remain scarce. The few available mitochondrial genomes of nematomorphs are enriched with long inverted repeats, which are embedded in the coding sequences of their genes-a remarkably unusual feature exclusive to this phylum. Here, we obtain and annotate the repeats in the mitochondrial genome of another nematomorph species-Parachordodes pustulosus. Using genomic and transcriptomic libraries, we investigate the impact of inverted repeats on the read coverage of the mitochondrial genome. Pronounced drops in the read coverage coincide with regions containing long inverted repeats, denoting the 'blind spots' of short-fragment sequencing libraries. Phylogenetic inference with the novel data reveals multiple disagreements between the traditional system of Nematomorpha and molecular data, rendering several genera paraphyletic, including Parachordodes.

A New Species of Gordionus (Nematomorpha: Gordiida) from the Rocky Mountains of New Mexico.

The 19 genera within the phylum Nematomorpha contain approximately 350 species. The cosmopolitan genus Gordionus Müller, 1926 contains about 58 species, 6 of which occur in the contiguous United States of America. Recently, 2 new Gordionus species were described from high-altitude streams within the southern Rocky Mountains, near Santa Fe, New Mexico. Here we describe another new Gordionus species, from a high-altitude stream in the southern Rocky Mountains, from near Taos, New Mexico. The sites consisted of temporary puddles and a small human-made stream at 3,175-3,250-m altitude in aspen/pine woodland. Gordionus lokeri n. sp. has 1 areole type, which varies in shape and size between and within body regions. Midbody areoles are elongated, polygonal, or triangular, shingled, with the raised side of the areole serrated. The interareolar space is narrow, containing few bristles. The male cloacal opening is surrounded inside and outside by narrow branching bristles that bifurcate or trifurcate deeply; the furcae then subdivide several times terminally. Adhesive warts are lacking. Genetic data, consisting of partial cytochrome c oxidase subunit I (COI) gene sequences, clearly separated G. lokeri n. sp. from other Nearctic species. This is the third Gordionus species described from high-elevation streams in the Rocky Mountains. It appears that this high-altitude habitat represents the preferential niche for numerous species of this genus, and thus future work should focus on describing gordiid diversity in other parts of the Rocky Mountains.

Gordius gonzalezi, a new species of horsehair worms (Nematomorpha) from Spain.

A new species, Gordius gonzalezi, is described from the Iberian Peninsula, from the Sierra de los Tormantos in Central Spain. Characteristic for the species is the presence of multiple short spines on the cuticle, not present in this form in any other Gordius species. Additionally, two further specimens are reported, which could not be determined to species level. One male of the genus Gordius is close to G. aquaticus and one female with regular areoles could belong either to the genus Gordius or to Gordionus.

Helminth parasites of the lesser great cormorant Phalacrocorax carbo sinensis from two nesting regions in the Czech Republic.

Parasitological examinations of 102 specimens of the lesser great cormorant Phalacrocorax carbo sinensis (Blumenbach) from two nesting regions in the Czech Republic (South Bohemia and South Moravia) were carried out at the Institute of Parasitology, Czech Academy of Sciences (previously the Czechoslovak Academy of Sciences) in the years 1987-1992. In them, a total of 19 species of helminth parasites was found, including Trematoda (11 species), Cestoda (2), Nematoda (4) and Acanthocephala (2), which can be divided into three main groups regarding their host specificity: parasites specific for cormorants (Phalacrocorax spp.) (37%), those parasitic mainly in cormorants (16%) and non-specific parasites (47%). Of the 19 species recorded, 100% were found in South Moravia, but only 47% of these 19 species in South Bohemia. The higher number of helminth species in cormorants from South Moravia and a higher proportion of non-specific species may be associated with the presence of the large Nové Mlýny water reservoir, in addition to better ecological and environmental conditions in this warmer region. Scanning electron microscopical examination of three common nematode species parasitising cormorants, Contracaecum rudolphii Hartwich, 1964, Desmidocercella incognita Solonitsin, 1932 and Syncuaria squamata (von Linstow, 1883), revealed some taxonomically important, previously unreported morphological features, such as the cephalic structures, numbers and distribution of male caudal papillae or the shapes of spicules.

[Cuticle ultrastructure of the fresh-water horsehair worm Gordionus alpestris (Villot, 1885) (Nematomorpha)].

The cuticular structure of the horsehair worm Gordionus alpestris (Villot, 1885) was studied under scanning and transmission electron microscopes. Adult worms were collected in the Syuk River near Nickel' Village in the Republic of Adygea (Russia) in June 2013. In the sampling area, the G. alpestris juveniles parasitize diplopods Pachyiulus krivolutskyi Golovatch, 1977. Similarities with other Nematomorpha species with the known cuticle ultrastucture are discussed.

Comparative descriptions of non-adult stages of four genera of Gordiids (Phylum: Nematomorpha).

Freshwater hairworms infect terrestrial arthropods as larvae but are free-living in aquatic habitats as adults. Estimates suggest that only 18% of hairworm species have been described globally and biodiversity studies on this group have been hindered by unreliable ways of collecting adult free living worms over large geographical areas. However, recent work indicates that non-adult cyst stages of hairworms may be the most commonly encountered stages of gordiids in the environment, and can be used for discovering the hidden diversity of this group. Unfortunately, little information is available on the morphological characteristics of non-adult stages of hairworms. To address this problem, we describe and compare morphological characteristics of non-adult stages for nine species of African and North American gordiids from four genera (Chordodes, Gordius, Paragordius, and Neochordodes). Observations were made on the oviposition behavior of adult worms and morphological characteristics were recorded for egg strings, larvae and cysts using light and differential interference contrast microscopy and/or scanning electron microscopy. Our study indicates that three distinct types of oviposition behaviors and three distinct morphological types of egg string, larva, and cysts were present among the four genera of gordiids. Although species identification based on cyst characteristics was not always possible among different species of gordiids, cyst morphology was conserved among some genera and all clades of gordiids. More importantly, our work indicates that gordiid larval morphology can be used for predicting cyst morphology among other gordiid genera. The capability to identify and predict gordiid genera and/or clades based on cyst morphology will be useful for culturing gordiids in the laboratory from field collected cysts and these new techniques will undoubtedly allow others to discover new species of gordiids from around the world.

Influence of site, season, silvering stage, and length on the parasites of the European eel Anguilla anguilla in two Mediterranean coastal lagoons of the island of Corsica, France using indicator species method.

The parasites of 425 European eels, Anguilla anguilla, were studied between 2009 and 2012 in two Mediterranean coastal lagoons of the island of Corsica, France. An indicator value (IndVal) method was used for analysis, which combines measures of fidelity and specificity. Because of its resilience to detect changes in abundance, IndVal is an effective ecological bioindicator. The IndVal method demonstrated that site, season, silvering stage, and length could influence the occurrence of parasite species in European eel. A randomization test identified ten parasite species as having a significant indicator value for site (lagoons differed principally in salinity: oligohaline to polyhaline for the Biguglia lagoon and polyhaline to euhaline for the Urbino lagoon; the digeneans Bucephalus anguillae and Lecithochirium musculus, the cestodes Bothriocephalus claviceps, Proteocephalus macrocephalus, and larvae of Myzophyllobothrium sp., the nematodes Anguillicoloides crassus, and encysted larvae of Contracaecum sp., the acanthocephalan Acanthocephaloides incrassatus, the monogenean Pseudodactyogyrus anguillae, and the copepod Ergasilus gibbus); one parasite species for the spring season (the acanthocephalan A. incrassatus); six parasite species for silvering stage (yellow, pre-silver, silver; the trematodes B. anguillae and Deropristis inflata, encysted larvae of the nematode Contracaecum sp., the acanthocephalan A. incrassatus, the monogenean P. anguillae, and the copepod E. gibbus); and three parasite species for some of the five length classes (the cestode P. macrocephalus, encysted larvae of the nematode Contracaecum sp., and the monogenean P. anguillae). Data for species composition and infection levels should help to improve the management of parasitism in the populations of European eels.

Endohelminth parasites of the blacktail comber Serranus atricauda (Pisces: Serranidae), from Madeira Archipelago (Atlantic Ocean).

Four different endohelminth parasite taxa were found in the viscera of the blacktail comber Serranus atricauda Günther, 1874 caught in the Madeira Archipelago. Nematodes were the dominant group, represented by 2 different taxa, Hysterothylacium spp. Ward & Magath, 1917 and Procamallanus (Spirocamallanus) halitrophus Fusco & Overstreet, 1978 comb. n. Plerocerci of the trypanorhynch Pseudogrillotia epinepheli (synonym: Grillotia epinepheli) Scholz, Garippa & Scala, 1993, and cystacanths of the acanthocephalan Bolbosoma vasculosum Rudolphi, 1819 were found in the visceral cavity. New host records for P. (S.) halitrophus and P. epinepheli and the extension of the geographic distribution of these 2 parasite species provide evidence of parasite transference between the Madeira Archipelago, the Mediterranean and the Gulf of Mexico. The paucity of the parasite fauna of blacktail comber reflect a combination of fish host selective feeding on particular dietary items and its territorial behaviour.

Gastrointestinal helminths of Gentoo penguins (Pygoscelis papua) from Stranger Point, 25 de Mayo/King George Island, Antarctica.

The aim of this work is to contribute to the knowledge of gastrointestinal parasites of the Gentoo penguin (Pygoscelis papua) from 25 de Mayo/King George Island (South Shetlands, Antarctica). Gastrointestinal tracts of 37 fresh dead individuals (21 chicks, 10 juveniles, and 6 adults) were collected from December 2006 to February 2012 and examined for macroparasites. Four adult parasite species were found: one Cestoda species (Parorchites zederi), two Nematoda species (Stegophorus macronectes and Tetrameres wetzeli), and one Acanthocephalan (Corynosoma shackletoni). Two species of immature acanthocephalans, Corynosoma hamanni and Corynosoma bullosum, were found in a single host. This is the first record of Tetrameres wetzeli in Gentoo penguins. The low parasite richness observed could be related to the stenophagic and pelagic diet of this host species which feeds almost exclusively on krill.

Novel techniques for biodiversity studies of gordiids and description of a new species of Chordodes (Gordiida, Nematomorpha) from Kenya, Africa.

We review recent advances in the use of non-adult gordiid cyst stages to locate gordiids over large geographical regions and new culturing techniques which can help overcome current difficulties in nematomorph biodiversity studies. Using these techniques, we collected a new species of gordiid as cysts in aquatic snails (Biomphalaria pfeifferi) from the Lake Victoria Basin, western Kenya, Africa and cultured them in the laboratory. We describe the adult free-living male and female worms using morphological (light and scanning electron microscopy) and molecular data as well as the life cycle, mating and oviposition behavior, egg strings, eggs, larvae, and cysts of this new species. Chordodes kenyaensis n. sp. belongs to a large group of African Chordodes in which simple areoles are smooth or superficially structured less so than "blackberry" areoles but contain filamentous projections. Present among the simple areoles are clusters of bulging areoles, crowned and circurmcluster areoles along with thorn and tubercle areoles. In the laboratory, worms developed and emerged within 53-78 days from three, species of laboratory-reared crickets exposed to cysts of this species. Adult male and female C. kenyaensis n. sp. initiated typical Gordian knots within hours to days of being placed together and males deposited masses of sperm on the cloacal region of females. Females began oviposition within a week of copulating and attached egg strings in a continuous zigzag pattern on small branches or air-hoses but never free in the water column. Larvae hatched within two to three weeks, and cysts developed in laboratory-reared and exposed snails within 14-24 days. Morphological characteristics of egg strings, eggs, larvae and cysts of C. kenyaensis were most similar to other gordiids in the genus Chordodes but differed morphologically from other gordiid genera for which similar information is available.

An anatomical description of a miniaturized acorn worm (hemichordata, enteropneusta) with asexual reproduction by paratomy.

The interstitial environment of marine sandy bottoms is a nutrient-rich, sheltered habitat whilst at the same time also often a turbulent, space-limited, and ecologically challenging environment dominated by meiofauna. The interstitial fauna is one of the most diverse on earth and accommodates miniaturized representatives from many macrofaunal groups as well as several exclusively meiofaunal phyla. The colonization process of this environment, with the restrictions imposed by limited space and low Reynolds numbers, has selected for great morphological and behavioral changes as well as new life history strategies.Here we describe a new enteropneust species inhabiting the interstices among sand grains in shallow tropical waters of the West Atlantic. With a maximum body length of 0.6 mm, it is the first microscopic adult enteropneust known, a group otherwise ranging from 2 cm to 250 cm in adult size. Asexual reproduction by paratomy has been observed in this new species, a reproductive mode not previously reported among enteropneusts. Morphologically, Meioglossus psammophilus gen. et sp. nov. shows closest resemblance to an early juvenile stage of the acorn worm family Harrimaniidae, a result congruent with its phylogenetic placement based on molecular data. Its position, clearly nested within the larger macrofaunal hemichordates, suggests that this represents an extreme case of miniaturization. The evolutionary pathway to this simple or juvenile appearance, as chiefly demonstrated by its small size, dense ciliation, and single pair of gill pores, may be explained by progenesis. The finding of M. psammophilus gen. et sp. nov. underscores the notion that meiofauna may constitute a rich source of undiscovered metazoan diversity, possibly disguised as juveniles of other species.

Helminths found in marmosets (Callithrix penicillata and Callithrixjacchus) introduced to the region of occurrence of golden lion tamarins (Leontopithecusrosalia) in Brazil.

The introduction of exotic species can increase the risk of extinction of native species through the introduction of new diseases, predation or resource competition. The marmosets Callithrix penicillata and Callithrix jacchus and hybrids of these two species have been introduced to privately owned forests in the lowland Atlantic forest of the Rio de Janeiro State in Brazil, the region of occurrence of the endangered golden lion tamarin, Leontopithecus rosalia. Because the ecology and biology of the marmosets and tamarins is similar, there is a reasonable risk that the marmosets would transmit pathogens such as endo parasites. The objective of this study was to identify the helminth fauna present in the introduced marmosets through an analysis of fecal samples of wild caught animals, and to evaluate the parasitological profile according to age, sex and geographical location. Eggs belonging to the Acanthocephala and Nematoda were found in the feces. One nematode egg type was identified as being Primasubulura jacchi. The ocurrence of nematodes was higher in males, acanthocephala were found in all age groups and sexes and P. jacchi was found with higher frequency in adult females. The geographic distribution analysis revealed that some of the forests had a higher predominance of parasites. Little is known about the pathology of parasites in free living Neotropical mammals, and this knowledge would be necessary to infer about the risk (form a parasitological standpoint) that the marmoset presence represents for the survival of the endangered golden lion tamarin.

Effect of Lysimachia ramosa (Primulaceae) on helminth parasites: motility, mortality and scanning electron microscopic observations on surface topography.

The alcoholic extract of Lysimachia ramosa Wall (Primulaceae) was tested in vitro against helminth parasites, Fasciolopsis buski and Ascaris suum, from porcine hosts and Raillietina echinobothrida from domestic fowl. The live adult parasites, collected from a freshly autopsied host, were exposed to different concentrations (5-50mg) of the test plant extract in physiological phosphate-buffered saline (PBS) having 0.1% dimethyl sulphoxide (DMSO) at 37+/-1 degrees C. The treated parasites revealed complete inactivation and flaccid paralysis that was followed by death at varying periods of time. A dose-dependent loss of motility and mortality was observed in all the treated parasites. Scanning electron microscopic observations revealed conspicuous deformity of the surface architecture in all the parasites exposed to the test plant extract. The general tegument in F. buski showed shrinkage and loss of scale-like spines; proglottides all along the strobilar length in R. echinobothrida appeared shrunken and deformed and the cuticular surface of A. suum appeared disorganised, having lost transverse striations. The botanicals of the test plant seem to be effective against all the three types of helminth parasites.

Morphology of larval Gordius dimorphus (Nematomorpha: Gordiida).

Scanning electron microscopy was used to analyze superficial features of Gordius dimorphus Poinar, 1991, larvae that might serve as generic or specific diagnostic characters. Three adults of G. dimorphus (2 males and 1 female) were maintained under laboratory conditions until oviposition, which occurred within long strings commonly referred to as egg strings. Larvae have a cylindrical body, annulated and divided into 2 sections, plus an anterior preseptum and a posterior postseptum. Three concentric rings with 6 spines each surround the proboscis. The proboscis is retractile, dorsoventrally flattened, with 1 pair of forceps-like projections on its distal-most portion. On the surface of each projection, 3 pairs of aculeiforms spines are aligned and lean toward the proboscis opening. One large spine is present on the posterior portion of the postseptum. Papillae were not observed. Gordius dimorphus larvae are similar to previous light microscope descriptions. This is the first record of G. dimorphus in Brazil.

Helminths parasitizing larval fish from Pantanal, Brazil.

Fish larvae of 'corvinas' (Pachyurus bonariensis and Plagioscion ternetzi) from Sinhá Mariana Lagoon, Mato Grosso State, were collected from March 2000 to March 2004, in order to determine the parasitic fauna of fishes. Larvae from the two species were parasitized by the same endoparasites: Contracaecum sp. Type 2 (larvae) (Nematoda: Anisakidae) in the mesentery and Neoechinorhynchus (Neoechinorhynchus) paraguayensis (Acanthocephala: Neoechinorhynchidae) in the stomach and the terminal portion of the intestine. Statistical analysis showed that there was a significant positive correlation between the standard length of hosts and the abundance of acanthocephalans and nematodes, and that the prevalence of nematodes presented a significant positive correlation with the standard length of the two species of hosts, indicating the presence of a cumulative process of infection. The present study constitutes the first record of nematodes and acanthocephalans parasitizing larval fish, as well as the first record of endoparasites in fish larvae in Brazil. In addition, it lists a new locality and two species of hosts for Contracaecum sp. Type 2 (larva) and N. (N.) paraguayensis.

In vitro anthelmintic effects of cysteine proteinases from plants against intestinal helminths of rodents.

Infections with gastrointestinal (GI) nematodes are amongst the most prevalent worldwide, especially in tropical climates. Control of these infections is primarily through treatment with anthelmintic drugs, but the rapid development of resistance to all the currently available classes of anthelmintic means that alternative treatments are urgently required. Cysteine proteinases from plants such as papaya, pineapple and fig are known to be substantially effective against three rodent GI nematodes, Heligmosomoides polygyrus, Trichuris muris and Protospirura muricola, both in vitro and in vivo. Here, based on in vitro motility assays and scanning electron microscopy, we extend these earlier reports, demonstrating the potency of this anthelmintic effect of plant cysteine proteinases against two GI helminths from different taxonomic groups - the canine hookworm, Ancylostoma ceylanicum, and the rodent cestode, Rodentolepis microstoma. In the case of hookworms, a mechanism of action targeting the surface layers of the cuticle indistinguishable from that reported earlier appears to be involved, and in the case of cestodes, the surface of the tegumental layers was also the principal location of damage. Hence, plant cysteine proteinases have a broad spectrum of activity against intestinal helminths (both nematodes and cestodes), a quality that reinforces their suitability for development as a much-needed novel treatment against GI helminths of humans and livestock.

Review on electron microscopy in taxonomy and biology of parasitic Nemathelminthes.

Electron microscopy (EM) proved a very helpful means that solved a lot of information in different scientific aspects. EM is a very good tool in the hospitals and research centers. It was aimed to pile up available information on the biology in the descriptive morphology of nematodes and their immature stages by scanning (SEM) and transmission (TEM) electron microscopy. Watson (1965a, b) studied Euchromadora vulgaris and Ascaris sp. by using TEM respectively. Lee (1969) investigated the ultra-structure of Nippostrongylus brasiliensis by SEM & TEM, as well as some nematodes by TEM (Lee, 1972). The topography of the adult Baylisascaris procyonis caudal end was illustrated by Snyder (1989). Male tail relatively long, smoothly attenuated, with a small button-like or mucronate termination. Pre-anal papillae situated ventrally in 2 slightly divergent and somewhat irregularly spaced rows. Anterior and posterior to anus 2 slightly raised roughened patches consisting of several rows of small spines. Just anterior to anus along outer margin of pre-anal roughened patch, a large double medio-ventral papilla. Five pairs of post-anal papillae with first pair just posterior to anus doubled and 4 pairs more closely associated in a group near tail end. Second pair with doubled papillae; but, in a few specimens fused as if 2 single closely associated papillae. Three pair single. Fourth pair of caudal papillae phasmids and in centers of each a ringed pore-like opening. Male spicules with a highly sculptured surface with a pincher-like terminal end.

Ultrastructure of the protonephridial system in Neodasys chaetonotoideus (Gastrotricha: Chaetonotida) and in the ground pattern of Gastrotricha.

The taxon Neodasys has a basal position within Gastrotricha. This makes it very interesting for phylogenetic considerations in this group. To complete the reconstruction of the nephridial system in the stem species of Gastrotricha started earlier, we have studied the whole protonephridial system of Neodasys chaetonotoideus by means of complete sets of ultrathin sections and TEM. In many characters, protonephridia of N. chaetonotoideus resemble those of macrodasyidan gastrotrich species. For example, each of the six protonephridia, arranged in three pairs, consists of three distinct cells that constitute the continuous protonephridial lumen. Especially, the terminal cell of the protonephridia of N. chaetonotoideus shows a striking pattern: The perforation of the filter region is a meandering cleft that is continuous with the seam of the enfolded lumen of that cell. With the results presented here and that of former TEM studies, we give a comprehensive idea of the excretory organs in the ground pattern of Gastrotricha. Moreover, we can elaborate on the hypothesized protonephridial system in the stem species of Bilateria. We suggest that a meandering filtration cleft is a feature of the ground pattern of the Bilateria.

Parasite survey of the eastern oyster Crassostrea virginica in coastal lagoons of the southern Gulf of Mexico.

A parasitological study of the eastern oyster Crassostrea virginica from 11 coastal lagoons in the southern Gulf of Mexico in dry and rainy seasons between late 1999 and early 2001 revealed the presence of 36 bacterial, 2 protozoan (Nematopsis prytherchi and Perkinsus marinus), and 4 helminth species (Urastoma cyprinae, Proctoeces maculatus, a Bucephalus sp., and a Tylocephalum sp.). The prevalence and mean abundances for the protozoa and helminths varied widely between locations but were generally below 50%. Nematopsis prytherchi and the Tylocephalum sp. were the most prevalent species (values were above 60% in most locations). Perkinsus marinus was present in oysters of eight of the coastal lagoons and had low prevalence (<30%) in almost all samples. All identified protozoa and helminths are widely distributed in the Gulf of Mexico and are common oyster parasites. Only P. marinus and the Bucephalus sp. were associated with damage to host tissues. In addition to these parasites, Rickettsia-like bacteria were found in the digestive gland and gills and viral gametocytic hypertrophy inclusions in the gonads by histological examination.