Phylogenetic position of Acanthobothrium cleofanus (Cestoda: Onchoproteocephalidea) using molecular evidence.

Despite the large number of species described to date for the onchoprotepcephalid genus Acanthobothrium (207), only 16 named species have a genetic sequence. With this background, specimens of adult cestodes of the stingray Hypanus longus were collected off San Blas, Nayarit, and onchoproteocephalid larvae in the carangid fish Trachinotus rhodopus from Puerto Ángel, Oaxaca, both located on the Pacific coast of Mexico. The objective of this work is to investigate the phylogenetic position of these adults and larvae using nuclear ribosomal markers (18S rDNA and 28S rDNA). Morphologically, adult specimens were identified as Acanthobothrium cleofanus; larvae were identified only to family level. The phylogenetic position of both taxa was investigated based on the information of two nuclear molecular markers analyzed under Parsimony (PA) and Bayesian Inference (BI) methods. The newly generated sequences of A. cleofanus from Nayarit are identical to the sequences of several samples of Acanthobothrium sp. collected in the Mexican Pacific, which sequence are available in GenBank; DNA sequences obtained from onchoproteocephalid larva clearly place this taxon within Acanthobothrium but representing an independent lineage. In the resulting phylogenetic trees, Uncibilocularis okei was found nested within Acanthobothrium with an unstable position depending on the optimality criteria, indicating the need for more molecular analyzes with a greater number of species of both genera prior to define its phylogenetic relationships.

Exploring parasites in extreme environments of high conservational importance: Artemia franciscana (Crustacea: Branchiopoda) as intermediate host of avian cestodes in Andean hypersaline lagoons from Salar de Atacama, Chile.

The hypersaline lagoons located in evaporation basins or salars (salt flats) in the Atacama Desert are extreme environments harbouring a specialised biota able to survive harsh conditions for life. The knowledge of the parasitic biodiversity of these extreme habitats is still scarce despite their functional importance in regulating relevant non-economic services like habitats of waterbirds. The present study is the first report on the cestode infection of Artemia franciscana Kellogg in Salar de Atacama lagoons in northern Chile. A total of 23 parasite larvae were isolated and identified as belonging to five cestode taxa of the order Cyclophyllidea: two species of the family Hymenolepididae, i.e. Flamingolepis sp. 1 and Flamingolepis sp. 2 (adults parasitic in flamingos); two species of Dilepididae, i.e. Fuhrmannolepis averini (adults parasitic in phalaropes) and Eurycestus avoceti (adult parasitic in charadriforms birds); and one species of Progynotaeniidae, i.e. Gynandrotaenia (?) stammeri (adult parasitic in flamingos). The cysticercoids of each species are described and figured. The study represents the first geographical record of the genera Eurycestus, Gynandrotaenia and Fuhrmannolepis in South America and the first report of Gynandrotaenia and Flamingolepis in A. franciscana in its native range. This survey also contributes to the knowledge of cestodes of Phoenicopteriformes and Charadriiformes and their life cycles in the Neotropical Region. A review of cestodes recorded in brine shrimps of the genus Artemia in the world is provided. Further studies on cestode fauna of aquatic birds and their intermediate hosts in hypersaline habitats of the Neotropical Region are needed to understand their functional role in such extreme and unique ecosystems.

Cestode strobilation: prediction of developmental genes and pathways.

BACKGROUND: Cestoda is a class of endoparasitic worms in the flatworm phylum (Platyhelminthes). During the course of their evolution cestodes have evolved some interesting aspects, such as their increased reproductive capacity. In this sense, they have serial repetition of their reproductive organs in the adult stage, which is often associated with external segmentation in a developmental process called strobilation. However, the molecular basis of strobilation is poorly understood. To assess this issue, an evolutionary comparative study among strobilated and non-strobilated flatworm species was conducted to identify genes and proteins related to the strobilation process. RESULTS: We compared the genomic content of 10 parasitic platyhelminth species; five from cestode species, representing strobilated parasitic platyhelminths, and five from trematode species, representing non-strobilated parasitic platyhelminths. This dataset was used to identify 1813 genes with orthologues that are present in all cestode (strobilated) species, but absent from at least one trematode (non-strobilated) species. Development-related genes, along with genes of unknown function (UF), were then selected based on their transcriptional profiles, resulting in a total of 34 genes that were differentially expressed between the larval (pre-strobilation) and adult (strobilated) stages in at least one cestode species. These 34 genes were then assumed to be strobilation related; they included 12 encoding proteins of known function, with 6 related to the Wnt, TGF-ß/BMP, or G-protein coupled receptor signaling pathways; and 22 encoding UF proteins. In order to assign function to at least some of the UF genes/proteins, a global gene co-expression analysis was performed for the cestode species Echinococcus multilocularis. This resulted in eight UF genes/proteins being predicted as related to developmental, reproductive, vesicle transport, or signaling processes. CONCLUSIONS: Overall, the described in silico data provided evidence of the involvement of 34 genes/proteins and at least 3 developmental pathways in the cestode strobilation process. These results highlight on the molecular mechanisms and evolution of the cestode strobilation process, and point to several interesting proteins as potential developmental markers and/or targets for the development of novel antihelminthic drugs.

Gill metazoan parasites of the spotted goatfish Pseudupeneus maculatus (Ostheichthyes: Mullidae) from the Coast of Pernambuco, northeastern Brazil / Metazoários parasitos de brânquias do saramunete Pseudupeneus maculatus (Ostheichthyes: Mullidae) da costa de Pernambuco, Nordeste do Brasil

Abstract This study evaluated the parasite fauna on the gills of spotted goatfish Pseudupeneus maculatus captured in the dry and rainy seasons in the coast of the State of Pernambuco, Brazil. Eight parasite species were identified belonging to the following taxa: Monogenea (Haliotrema caraïbensis, Haliotrema caballeroi and Haliotrema golvani); Crustacea (Rocinela signata, Hamaticolax scutigerulus and Caligidae gen. sp.) and Cestoda (Nybelinia indica and Pseudolacistorhynchus noodti). The most prevalent parasites were: Monogenea (100%), H. scutigerulus (35%), N. indica (11.7%), R. signata (8.3%), Caligidae gen. sp. (3.33%) and P. noodti (0.83%). Values of infestation are compared to other studies, and the uncommon occurrence of Trypanorhyncha on the gills suggests that the spotted goatfish could be an intermediate host for the parasite.

Resumo O presente estudo investigou a fauna parasitária das brânquias do peixe conhecido como saramunete Pseudupeneus maculatus, capturados nas estações seca e chuvosa na costa do estado de Pernambuco, Brasil. Oito espécies de parasitos foram identificadas, pertencentes aos seguintes táxons: Monogenea (Haliotrema caraïbensis, Haliotrema caballeroi e Haliotrema golvani); Crustacea (Rocinela signata, Hamaticolax scutigerulus e Caligidae gen. sp.) e Cestoda (Nybelinia indica e Pseudolacistorhynchus noodti). Os parasitos mais prevalentes foram: Monogenea (100%), H. scutigerulus (35%), N. indica (11,7%), R. signata (8,3%), Caligidae gen. sp. (3,33%) e P. noodti (0,83%). Os valores de infestação são comparados a outros estudos, e a ocorrência incomum de cestóides Trypanorhyncha sugere que o saramunete pode ser um hospedeiro intermediário para o parasito.

Unique pharmacological properties of serotoninergic G-protein coupled receptors from cestodes.

BACKGROUND: Cestodes are a diverse group of parasites, some of them being agents of neglected diseases. In cestodes, little is known about the functional properties of G protein coupled receptors (GPCRs) which have proved to be highly druggable targets in other organisms. Notably, serotoninergic G-protein coupled receptors (5-HT GPCRs) play major roles in key functions like movement, development and reproduction in parasites. METHODOLOGY/PRINCIPAL FINDINGS: Three 5-HT GPCRs from Echinococcus granulosus and Mesocestoides corti were cloned, sequenced, bioinformatically analyzed and functionally characterized. Multiple sequence alignment with other GPCRs showed the presence of seven transmembrane segments and conserved motifs but interesting differences were also observed. Phylogenetic analysis grouped these new sequences within the 5-HT7 clade of GPCRs. Molecular modeling showed a striking resemblance in the spatial localization of key residues with their mammalian counterparts. Expression analysis using available RNAseq data showed that both E. granulosus sequences are expressed in larval and adult stages. Localization studies performed in E. granulosus larvae with a fluorescent probe produced a punctiform pattern concentrated in suckers. E. granulosus and M. corti larvae showed an increase in motility in response to serotonin. Heterologous expression revealed elevated levels of cAMP production in response to 5-HT and two of the GPCRs showed extremely high sensitivity to 5-HT (picomolar range). While each of these GPCRs was activated by 5-HT, they exhibit distinct pharmacological properties (5-HT sensitivity, differential responsiveness to ligands). CONCLUSIONS/SIGNIFICANCE: These data provide the first functional report of GPCRs in parasitic cestodes. The serotoninergic GPCRs characterized here may represent novel druggable targets for antiparasitic intervention.

Gill metazoan parasites of the spotted goatfish Pseudupeneus maculatus (Ostheichthyes: Mullidae) from the Coast of Pernambuco, northeastern Brazil.

This study evaluated the parasite fauna on the gills of spotted goatfish Pseudupeneus maculatus captured in the dry and rainy seasons in the coast of the State of Pernambuco, Brazil. Eight parasite species were identified belonging to the following taxa: Monogenea (Haliotrema caraïbensis, Haliotrema caballeroi and Haliotrema golvani); Crustacea (Rocinela signata, Hamaticolax scutigerulus and Caligidae gen. sp.) and Cestoda (Nybelinia indica and Pseudolacistorhynchus noodti). The most prevalent parasites were: Monogenea (100%), H. scutigerulus (35%), N. indica (11.7%), R. signata (8.3%), Caligidae gen. sp. (3.33%) and P. noodti (0.83%). Values of infestation are compared to other studies, and the uncommon occurrence of Trypanorhyncha on the gills suggests that the spotted goatfish could be an intermediate host for the parasite.

Cestodes of the blue shark, Prionace glauca (Linnaeus 1758), (Carcharhiniformes: Carcharhinidae), off the west coast of Baja California Sur, Mexico.

The cestode species recovered from the spiral intestines of 27 blue sharks (Prionace glauca) (Linnaeus, 1758) are reported from the western coast of Baja California Sur (BCS). The sampling was undertaken on a monthly basis from January 2003 to January 2004. The helminthological examination indicated the presence of four species of cestodes: Platybothrium auriculatum Yamaguti, 1952; Prosobothrium japonicum Yamaguti, 1934; Anthobothrium caseyi (Yamaguti, 1934) Ruhnke & Caira, 2009; and Paraorygmatobothrium prionacis (Yamaguti, 1934) Ruhnke, 1994. Of all the 27 sharks examined, 88.8% were infected with at least one cestode species. The most frequent species was P. auriculatum infecting 85% of the spiral intestines examined. In contrast the species with the highest mean intensity was P. prionacis (80.4 200). The species richness of cestodes in P. glauca is very similar in other regions of the world despite its wide distribution; however, this richness is low compared with other species of sharks within the same family. The feeding and host-specific are important factors that influence the parameters of infection of cestodes in this shark. On the west coast of BCS, Prionace glauca feeds mainly on red crab Pleuroncodes planipes Stimpson, 1860; squids Gonatus californiensis Young, 1972, Ancistrocheirus lesueurii (D'Orbigny, 1842), Haliphron atlanticus Steenstrup, 1861, and low proportion of fish teleosts as Merluccius productus (Ayres, 1855), Sardinops sp. Hubbs, 1929 and Scomber japonicus Houttuyn, 1872. We speculate that these prey could be involved as the second intermediate hosts of these cestodes, as in other members of these genera, although the life cycles of none are known.

Tunga penetrans and further parasites in the giant anteater (Myrmecophaga tridactyla) from Minas Gerais, Brazil.

The Brazilian savannah-like area, the Cerrado region, covers large areas of the country and provides a habitat for a multitude of different animal species. The giant anteater (Myrmecophaga tridactyla) is geographically widespread and one of the typical inhabitants of the Cerrado. They are listed as vulnerable by the International Union for Conservation of Nature and Natural Resources. A population loss of at least 30 % over the past 10 years has been estimated based on local extinctions, habitat loss and deaths caused by fires, roadkills and hunting. Little is known about ecological and in particular parasitic conditions of this highly specialised insectivore species. During September and November 2010 we examined three roadkilled giant anteater for the presence of metazoan ecto- and endoparasites. Besides the cestode species Oochoristica tetragonocephala and the tick species Amblyomma nodosum, we found for the first time the flea Tunga penetrans. Beside morphological flea species identification, we compared a fragment of the 16S rRNA gene of eggs, a molecular method utilised for the first time in this combination. The identification of T. penetrans in M. tridactyla represents a new host record and expands the host and distribution range of the zoonotic flea species.

Description of plerocerci and adults of a new species of Grillotia (Cestoda: Trypanorhyncha) in teleosts and elasmobranchs from the Patagonian shelf off Argentina.

A new species of Grillotia was found from teleosts and elasmobranchs along the Patagonian shelf off Argentina. Grillotia patagonica n. sp. is described from plerocerci recovered from gadiform (Moridae) and perciform fish (Cheilodactylidae, Bovichtidae, and Nototheniidae) and adults from the smallthorn sand skate Psammobatis rudis (Rajiformes, Rajidae). Grillotia patagonica most closely resembles species in the Grillotia erinaceus species complex (viz., Grillotia borealis, Grillotia brayi, Grillotia dollfusi, G. erinaceus, and Grillotia musculara) in having 4 hooks per principal row and 2 or more intercalary rows in the metabasal region, a band of hooks on the external surface of the tentacle, numerous proglottids, a hermaphroditic sac, internal and external seminal vesicles, uterine pore, and attachment of the retractor muscle in the mid region of the tentacular bulb. Grillotia patagonica n. sp. is unique among all valid species in the genus by having the hooks on the first row reduced and of a different shape from the rest of the metabasal rows. Despite the diversity of elasmobranchs that are available as definitive hosts for species in Grillotia, most species (10/14) are oioxenous or mesostenoxenous. The specificity for the last intermediate host is variable among species of Grillotia, with most plerocerci being oioxenous (5/15) or euryxenous (8/15). Host specificity is higher for the adult stage in the definitive host (mean HS(S) = 4.07) than for the plerocerci (mean HS(S) = 7.30). All the species with oioxenous specificity (either larvae or adults) have limited geographic distributions. Some previous records of species of Grillotia from fishes caught off Argentina require reconsideration, i.e., G. erinaceus, Grillotia minuta (reported as Grillotia bothridiopunctata) and G. borealis . An updated host-parasite checklist for the valid species of Grillotia is also presented along with new host records for Grillotia carvajalregorum.

[Larvae of Anisakidae nematodes and Trypanorhyncha cestodes of public health importance in Aluterus monoceros (Linnaeus, 1758) in Rio de Janeiro State, Brazil]. / Nematoides anisaquídeos e cestoides Trypanorhyncha de importância em saúde pública em Aluterus monoceros (Linnaeus, 1758) no Estado do Rio de Janeiro, Brasil.

One hundred specimens of unicorn leatherjacket, Aluterus monoceros purchased from markets of municipalities of Niterói and Rio de Janeiro from May to August 2006. The fishes were measured, necropsied, fileted and analysed their organs. Sixteen fishes were parasitized by nematode Anisakidae: Anisakis spp. and Contracaecum sp. with respectively, 1 and 16% of prevalence, 2 and 3.31 of mean intensity, and 0.02 and 0.53 of mean abundance. Two larvae of Anisakis sp. were found in mesentery of one fish and Contracaecum sp. was found in liver and mesentery with 1 to 9 specimens of range of infection. Fifty-one fishes were parasitized on the liver and mesentery by metacestodes of Trypanorhyncha. The collected species were Floriceps saccatus and Callitetrarhynchus speciosus with respectively, 45 and 6% of prevalence, 3.17 and 2.83 of mean intensity, and 1.43 and 0.06 of mean abundance, the range of infection by F. saccatus was 1 to 20 and by C. speciosus was 1 to 5. Anisakis sp. and these two species of Trypanothyncha were reported in A. monoceros for the first time.

Nematoides anisaquídeos e cestoides Trypanorhyncha de importância em saúde pública em Aluterus monoceros (Linnaeus, 1758) no Estado do Rio de Janeiro, Brasil / Larvae of Anisakidae nematodes and Trypanorhyncha cestodes of public health importance in Aluterus monoceros (Linnaeus, 1758) in Rio de Janeiro State, Brazil

Entre maio e agosto de 2006, foram adquiridos 100 espécimes de peixe-porco, Aluterus monoceros em estabelecimentos de pescado nos municípios de Niterói e Rio de Janeiro. Os peixes foram medidos, necropsiados, filetados e seus órgãos analisados. Foram encontrados 16 peixes parasitados por larvas de nematoides anisaquídeos pertencentes às espécies Anisakis sp. e Contracaecum sp., com prevalência de 1 e 16 por cento, intensidade média de 2 e 3,31 e abundância média de 0,02 e 0,53, respectivamente. Duas larvas de Anisakis sp. foram encontradas no mesentério de um peixe; e de Contracaecum sp. no fígado e mesentério, com amplitude de variação da intensidade de infecção de 1 a 9. Cinquenta e um peixes mostravam-se parasitados no fígado e mesentério por cestoides da ordem Trypanorhyncha. As espécies colhidas foram Floriceps saccatus e a Callitetrarhynchus speciosus, com a prevalência de 45 e 6 por cento, intensidade média de 3,17 e 2,83, variando de 1 a 20 e 1 a 5, e abundância média de 1,43 e 0,06, respectivamente. Larvas de Anisakis sp. e essas duas espécies de Trypanorhyncha foram registradas pela primeira vez parasitando A. monoceros.

One hundred specimens of unicorn leatherjacket, Aluterus monoceros purchased from markets of municipalities of Niterói and Rio de Janeiro from May to August 2006. The fishes were measured, necropsied, fileted and analysed their organs. Sixteen fishes were parasitized by nematode Anisakidae: Anisakis spp. and Contracaecum sp. with respectively, 1 and 16 percent of prevalence, 2 and 3.31 of mean intensity, and 0.02 and 0.53 of mean abundance. Two larvae of Anisakis sp. were found in mesentery of one fish and Contracaecum sp. was found in liver and mesentery with 1 to 9 specimens of range of infection. Fifty-one fishes were parasitized on the liver and mesentery by metacestodes of Trypanorhyncha. The collected species were Floriceps saccatus and Callitetrarhynchus speciosus with respectively, 45 and 6 percent of prevalence, 3.17 and 2.83 of mean intensity, and 1.43 and 0.06 of mean abundance, the range of infection by F. saccatus was 1 to 20 and by C. speciosus was 1 to 5. Anisakis sp. and these two species of Trypanothyncha were reported in A. monoceros for the first time.

Metazoan parasite infracommunities of the toadfish Aphos porosus (Pisces: Batrachoidiformes) in central Chile: how variable are they over time?

The present study examines variation in parasite community characteristics of the toadfish Aphos porosus across sampling years. We analyzed and compared the species composition and numeric descriptors of the parasite infrapopulations and infracommunities in 101 fish collected during the springs of 1999, 2006, and 2007 from rocky intertidal ponds in El Tabo, central Chile. Parasites were found in 94.1% of specimens necropsied. In total 5,532 parasites were collected, representing 12 taxa, of which 7 were found in the 3 annual samples. The most prevalent and abundant parasites in the 3 sampling years were larval tetraphyllidean cestodes, followed by anisakid nematodes. The community descriptors of average richness and abundance varied significantly across the 3 yr, with the exception of parasite dominance. The parasite species composition and relative abundance showed low variability among years. A few parasite taxa (Anisakis sp., Pseudoterranova sp., tetraphyllideans, and Clestobothrium crassiceps) dominated the infracommunities of the toadfish; however, tetraphyllideans were the parasites that greatly varied over time. Consequently the parasite infracommunities of the toadfish were variable among years, with a low variation in parasite composition, but large differences in the aggregate descriptors.

Oribatid mites as intermediate hosts of Thysanosoma actinioides (Cestoda: Anoplocephalidae): a preliminary study.

Thysanosoma actinioides Diesing, 1834 (Cestoda: Anoplocephalidae) parasitizes domestic and wild herbivores, and its life cycle has not yet been completely elucidated. The aim of this study was to analyze the role of oribatid mites as intermediate hosts of T. actinioides. The work was carried out at a Merino sheep breeding farm situated in the Pre-Cordillera region near Bariloche City, Río Negro Province, Argentina. The proglottids of T. actinioides were obtained from feces of infected sheep. In the laboratory, they were placed in the plastic wells with oribatid mites. The species of oribatids used in this experimental trial were Zygoribatula striassima Hammer, 1962 (Family Oribatulidae) and Oribatella spp. Banks, 1895 (Family Oribatellidae). Both species became infected with larval stages of T. actinioides. However, the infective cysticercoid stage did not develop.

Metacestodes of the family Dilepididae (Cestoda: Cyclophyllidea) parasitising fishes in Mexico.

A survey of metacestodes of dilepidid tapeworms (Cyclophyllidea) occurring in fish from Mexico is presented. They belong to the following species (those first reported from Mexico marked with an asterisk): Cyclustera capito (Rudolphi, 1819); (*)Cyclustera cf. ralli (Underwood & Dronen, 1986); Dendrouterina pilherodiae Mahon, 1956; (*)Glossocercus auritus (Rudolphi, 1819); (*)G. caribaensis (Rysavy & Macko, 1973); (*)Paradilepis caballeroi Rysavy & Macko, 1973; (*)Paradilepis cf. urceus (Wedl, 1855); (*) Paradilepis sp.; Parvitaenia cochlearii Coil, 1955; (*)Parvitaenia macropeos (Wedl, 1855); (*)Valipora campylancristrota (Wedl, 1855); (*)V. mutabilis Linton, 1927; and (*)V. minuta (Coil, 1950). Metacestodes of Dendrouterina papillifera (Fuhrmann, 1908), previously reported from the gall-bladder of the pimelodid catfish Rhamdia guatemalensis from Mexico by Scholz et al. (1996), belong actually to V. minuta. Data on the morphology of metacestodes, their fish hosts and rate of infection, site and distribution in Mexico are provided.

Role of the calcareous corpuscles in cestode physiology: a review.

Cysticercosis is a parasitic disease caused by the larval stage or cysticercus of the cestode tapeworm Taenia solium. Cysticerci are able to survive in the host tissues for long periods in the presence of an immune response. Tissues of cestodes contain mineral concretions termed calcareous corpuscles. These corpuscles might serve for the focal deposition of exceeding amounts of calcium protecting the larvae against calcification. Studies on the morphology and composition of calcareous corpuscles in cestodes have resulted in a number of hypotheses on their origin and function. Calcareous corpuscles are believed to form either intracellularly or extracellularly and the cell type involved, the place of formation and the mechanism of mineral deposition seem to be also diverse. This review intends to provide an updated guide to the published literature on calcareous corpuscles in cestodes, giving emphasis on their role in larval physiology. Understanding biomineralization might lead to novel ways for the treatment of diseases caused by cestode larvae.

Studies on the new species tylocephalum chiralensis parasite from dasyatis uarnak from Chirala coast, Andra Pradesh in India

Se describe la nueva especie tylocephalum chiralensis, parásito del pez elasmobranquio dasyatis uarnak de la costa de Chirala, andra Pradesh. Difiere de otras especies conocidas del género tylocephalum en el mayor tamaño de su cuerpo, ausencia de cuello, número de testículos, número de proglótidas, distribución de los folículos vitelinos y aberturas genitales

The metazoan parasite community of migrating greater yellowlegs, Tringa melanoleuca, from the Rio Grande Valley, Texas and New Mexico.

Forty-eight migrant greater yellowlegs, Tringa melanoleuca, collected from southwestern Texas and southeastern New Mexico were examined for metazoan parasites. Nine helminth and 7 ectoparasite species were collected. Five new host records were recorded. The helminth fauna showed little diversity, little concentration for dominance, and no significant positive or negative associations between species were found. All species of helminths showed a contagious distribution. The component helminth community consisted of 2 core, 3 secondary, and 4 satellite species, and there was no host specialist. A checklist of metazoan parasites reported from greater yellowlegs in North America is included.

Population biology of the Pseudophyllidean cestode Bothriocephalus teleosts (Malhotra, 1984) in the Indian hill- stream teleosts: I. Influence of season and temperature

La infección por el cestode Bothriocephalus teleostei (Malhotra, 1984) en teleósteos de aguas corrientes montañosas se ha presentado como un fenómeno asociado a la temperatura acuática. El cestode fue más prevalente en las épocas de comienzos de primavera y verano que en la época invernal, durante el período de 24 meses que duró el estudio (1979-1981)