Clinostomum complanatum: Anthelmintic potential of curcumin on the infective progenetic metacercarial stage.

The emerging resistance against commonly used antiparasitic drugs has driven investigators to explore alternative approaches using plant-derived active ingredients. These compounds have been tested for antiviral, antibacterial, and anthelmintic properties, particularly against adult worms. However, their effects on larval forms have been neglected. Curcumin is a polyphenol that is a significant constituent of the rhizome of Curcuma longa and possesses various biological activities, including antioxidant, anti-inflammatory, anti-infectious, and anti-carcinogenic. In the present study, the anthelmintic potential of curcumin was tested in vitro for its efficacy against the zoonotically important larval form, the progenetic metacercariae of Clinostomum complanatum, which were procured from the forage fish, Trichogaster fasciatus. Curcumin produced time and concentration-dependent inhibition in the motility of treated metacercarial worms, with the maximum inhibition of motility reported at 60 µM along with a significant increase of (36-92%) in ROS and (57-112%) in GSH levels at the end of a period of 6 h. In contrast, curcumin at the highest concentration significantly inhibited the activities of the antioxidant and detoxification enzymes SOD (36%) and GST (16%), respectively, in addition to altering the polypeptide profile and inhibiting cysteine proteases. The tegumental surface appeared to be highly disrupted in curcumin-treated worms, exhibiting severe blebbing, shearing of the tegument, and spine erosion. Such changes would affect the tegumental functions and survival of worms in the hostile microenvironment. This would render worms more susceptible to host-mediated rejection responses. Based on the results of the present study, it is inferred that C. complanatum could serve as an excellent model for screening novel anthelmintic drugs against larval trematodes of great economic significance. Furthermore, we conclude that curcumin could be exploited as an excellent phytotherapeutic agent against the virulent larval form under investigation.

Description of Lutziella swatensis sp. n (Trematoda: Dicrocoelidae) from Rattus rattus in Swat, Pakistan / Descrição de Lutziella swatensis sp. n (Trematoda: Dicrocoelidae) de Rattus rattus em Swat, Paquistão

A new species of the genus Lutziella (Rohde, 1966) Yamaguti, 1971 is described here and named Lutziella swatensis sp.nov. from the liver of rat (Rattus rattus L.). The new species is characterized by having body flat, smooth, longer than broad with maximum width at the level of the ovary, oral sucker with weak musculature, pharynx small; eosophagus long; caeca of irregular shape which bifurcate on the anterior border of the ovary in to unequal portions, acetabulum weakly muscular, post-testicular, testes lobed, cirrus pouch somewhat median, small in size containing winding seminal vesicle, prostatic complex and short ejaculatory duct. Genital pore median. Ovary post testicular, submedian; seminal receptacle overlapping ovary, laurer’s canal present. Vitellaria follicular extending on each side from almost the level of testes to anterior portion of posterior half of the body. Uterus filled with eggs occupying most of the body, eggs oval rather small, numerous, brownish in colour, excretory vesicle tubular with terminal pore. Lutziella swatensis n. sp. is the second species of the genus known from Pakistan as well as the second species described from murid rodents in the world.

Uma nova espécie do gênero Lutziella (Rohde, 1966) Yamaguti, 1971 é descrita aqui e denominada Lutziella swatensis sp.nov. do fígado do rato (Rattus rattus L.). A nova espécie é caracterizada por ter corpo liso, liso, mais longo que largo com largura máxima ao nível do ovário, otário oral com musculatura débil, faringe pequena; eosôfago longo; ceco de forma irregular que se bifurca na borda anterior do ovário em porções desiguais, acetábulo fracamente muscular, pós-testicular, testículos lobados, bolsa cirrus um pouco mediana, pequeno em tamanho contendo vesícula seminal sinuosa, complexo prostático e ducto ejaculatório curto. Mediana dos poros genitais. Ovário pós testicular, submediano; ovário sobreposto do receptáculo seminal, canal de laurer presente. Vitellaria folicular que se estende de cada lado de quase o nível dos testículos para a porção anterior da metade posterior do corpo. Útero cheio de ovos que ocupam a maior parte do corpo, oval ovos bastante pequenos, numerosos, de cor acastanhada, vesícula excretor tubular com poro terminal. Lutziella swatensis n. sp. é a segunda espécie do gênero conhecida do Paquistão, bem como a segunda espécie descrita de roedores do mundo.

A new species of hemiuroidean trematode from Hatcheria macraei (Siluriformes, Trichomycteridae) and Heleobia hatcheri (Gastropoda, Cochliopidae) in a Patagonian River.

A new hemiuroidean species, Genarchella pichileufuensis n. sp. (Derogenidae: Halipeginae), was found in the stomach of the siluriform freshwater fish, Hatcheria macraei (Girard, 1855), in the Pichileufu River, Patagonia, Argentina. Its rediae with immature cystophorous cercariae were found in the snail Heleobia hatcheri (Pilsbry, 1911) in the same site. The present new species is morphologically featured by having a cyclocoel in the hindbody unlike the other species of the genus. The characteristics of this species allowed us to amend the diagnosis of the genus Genarchella as follows: cyclocoel present or absent; testes symmetrical to tandem; ootype pouch present. In the phylogenetic analysis, G. pichileufuensis forms a well-supported clade with Genarchella spp. recovered from Mexican freshwater fishes. This clade is included in the cluster of representatives of the subfamily Halipeginae. So far, three hemiuroidean species, Thometrema patagonica (Szidat, 1956), Derogenes lacustris Tsuchida, Flores, Viozzi, Rauque et Urabe, 2021 and G. pichileufuensis n. sp., have been reported from freshwater fishes in Argentinean Patagonia.

Leeches as the intermediate host for strigeid trematodes: genetic diversity and taxonomy of the genera Australapatemon Sudarikov, 1959 and Cotylurus Szidat, 1928.

BACKGROUND: Leeches (Hirudinida) play a significant role as intermediate hosts in the circulation of trematodes in the aquatic environment. However, species richness and the molecular diversity and phylogeny of larval stages of strigeid trematodes (tetracotyle) occurring in this group of aquatic invertebrates remain poorly understood. Here, we report our use of recently obtained sequences of several molecular markers to analyse some aspects of the ecology, taxonomy and phylogeny of the genera Australapatemon and Cotylurus, which utilise leeches as intermediate hosts. METHODS: From April 2017 to September 2018, 153 leeches were collected from several sampling stations in small rivers with slow-flowing waters and related drainage canals located in three regions of Poland. The distinctive forms of tetracotyle metacercariae collected from leeches supplemented with adult Strigeidae specimens sampled from a wide range of water birds were analysed using the 28S rDNA partial gene, the second internal transcribed spacer region (ITS2) region and the cytochrome c oxidase (COI) fragment. RESULTS: Among investigated leeches, metacercariae of the tetracotyle type were detected in the parenchyma and musculature of 62 specimens (prevalence 40.5%) with a mean intensity reaching 19.9 individuals. The taxonomic generic affiliation of metacercariae derived from the leeches revealed the occurrence of two strigeid genera: Australapatemon Sudarikov, 1959 and Cotylurus Szidat, 1928. Phylogenetic reconstructions based on the partial 28S rRNA gene, ITS2 region and partial COI gene confirmed the separation of the Australapatemon and Cotylurus clades. Taking currently available molecular data and our results into consideration, recently sequenced tetracotyle of Australapatemon represents most probably Au. minor; however, unclear phylogenetic relationships between Au. burti and Au. minor reduce the reliability of this conclusion. On the other hand, on the basis of the obtained sequences, supplemented with previously published data, the metacercariae of Cotylurus detected in leeches were identified as two species: C. strigeoides Dubois, 1958 and C. syrius Dubois, 1934. This is the first record of C. syrius from the intermediate host. CONCLUSIONS: The results of this study suggest the separation of ecological niches and life cycles between C. cornutus (Rudolphi, 1808) and C. strigeoides/C. syrius, with potential serious evolutionary consequences for a wide range of host-parasite relationships. Moreover, phylogenetic analyses corroborated the polyphyletic character of C. syrius, the unclear status of C. cornutus and the separate position of Cotylurus raabei Bezubik, 1958 within Cotylurus. The data demonstrate the inconsistent taxonomic status of the sequenced tetracotyle of Australapatemon, resulting, in our opinion, from the limited availability of fully reliable, comparative sequences of related taxa in GenBank.

Molecular communication between the monogenea and fish immune system.

Monogeneans parasitise mainly the outer structures of fish, such as the gills, fins, and skin, that is, tissues covered with a mucous layer. While attached by sclerotised structures to host's surface, monogeneans feed on its blood or epidermal cells and mucus. Besides being a rich source of nutrients, these tissues also contain humoral immune factors and immune cells, which are ready to launch defence mechanisms against the tegument or gastrointestinal tract of these invaders. The exploitation of hosts' resources by the Monogenea must, therefore, be accompanied by suppressive and immunomodulatory mechanisms which protect the parasites against attacks by host immune system. Elimination of hosts' cytotoxic molecules and evasion of host immune response is often mediated by proteins secreted by the parasites. The aim of this review is to summarise existing knowledge on fish immune responses against monogeneans. Results gleaned from experimental infections illustrate the various interactions between parasites and the innate and adaptive immune system of the fish. The involvement of monogenean molecules (mainly inhibitors of peptidases) in molecular communication with host immune system is discussed.

Strigea robusta causes polydactyly and severe forms of Rostand's anomaly P in water frogs.

BACKGROUND: Cases of polydactyly in natural populations of amphibians have attracted great interest from biologists. At the end of the 1940s, the French biologist Jean Rostand discovered a polymorphic syndrome in some water frog (Anura: Pelophylax) populations that included polydactyly and some severe morphological anomalies (he called it 'anomaly P'). The cause of this anomaly remains unknown for 70 years. In a previous study, we obtained anomaly P in the laboratory in tadpoles of water frogs that developed together with molluscs Planorbarius corneus (Mollusca: Gastropoda) collected in the field. We thus proposed the 'trematode hypothesis', according to which the infectious agent responsible for anomaly P is a trematode species. METHODS: Metacercariae from tadpoles with anomaly P were identified using ITS2 gene sequencing as Strigea robusta (Trematoda: Strigeidae). To verify teratogenic features of the species, cercariae of S. robusta were tested for the possibility to cause anomalies. Identification of cercariae species was made using morphological and molecular methods (sequencing of ITS2 and 28S rRNA). The tadpoles were exposed to parasites at four doses of cercariae (control, low, medium and high) and divided into two groups: "early" (at 25-27 Gosner stages) and "late" (at 29-34 Gosner stages) exposure. RESULTS: A total of 58 (72.5%) tadpoles survived until metamorphosis under the dose-dependent experiment with the trematode S. robusta. Differences in the survival rates were observed between the exposed and unexposed tadpoles both in the group of "early" tadpoles and "late" tadpoles. The exposure of tadpoles to the cercariae of S. robusta induced anomaly P in 82% of surviving tadpoles. The severe forms developed only in "early" stages under all doses of cercariae exposure. Polydactyly predominantly developed in the "late" stages; under a light exposure dose, polydactyly also developed in "early" tadpoles. Laboratory-hatched tadpoles reared together with infected snails had different rates of survival and complexity of deformations associated with the period of coexistence. CONCLUSIONS: The experiments with direct cercariae exposure provide compelling evidence that S. robusta leads to anomaly P in tadpoles of water frogs. The manifestation of anomaly P turned out to be dependent on the stage of development, cercariae dose, and the location of the cysts.

Missing link: California rock crabs serve as intermediate hosts for the parasite Helicometrina nimia.

Parasites can have strong effects on invertebrate host behaviour, fecundity and survival in marine ecosystems. However, parasites are often poorly documented and still rarely integrated into marine ecological modelling; comprehensive surveys of infection in marine invertebrates are sporadic at best. For example, rock crabs are an important part of Californian coastal ecosystems, both as regulators of mussel populations and non-native species, and as prey items for predators like sea otters, but their parasite communities and potential effects on crab population dynamics are seldom studied or understood. Here, we present the first report of infection by the trematode Helicometrina nimia in the economically and ecologically important red rock crab (Cancer productus) and Pacific rock crab (Romaleon antennarium). As intermediate hosts, they are a missing link for infection by H. nimia in Californian fish that was unreported until now. Based on these findings, we advocate for further research into parasite diversity and their potential effects on ecologically and commercially important species.

High diversity of fish ectoparasitic monogeneans (Dactylogyrus) in the Iberian Peninsula: a case of adaptive radiation?

The epicontinental fauna of the Iberian Peninsula is strongly influenced by its geographical history. As the possibilities for dispersion of organisms into and from this region were (and still are) limited, the local fauna consists almost exclusively of endemic species. Almost all Iberian freshwater fishes of the families Leuciscidae and Cyprinidae are endemic and on-going research on these taxa continually uncovers new species. Nevertheless, information on their host-specific parasites remains scarce. In this study, we investigate the diversity and phylogenetic relationships in monogeneans of the genus Dactylogyrus (gill ectoparasites specific to cyprinoid fish) in the Iberian Peninsula. Twenty-two species were collected and identified from 19 host species belonging to Cyprinidae and Leuciscidae. A high degree of endemism was observed, with 21 Dactylogyrus species reported from Iberia only and a single species, D. borealis, also reported from other European regions. Phylogenetic analysis split the endemic Iberian Dactylogyrus into two well-supported clades, the first encompassing Dactylogyrus parasitizing endemic Luciobarbus spp. only, and the second including all Dactylogyrus species of endemic leuciscids and four species of endemic cyprinids. Species delimitation analysis suggests a remarkable diversity and existence of a multitude of cryptic Dactylogyrus species parasitizing endemic leuciscids (Squalius spp. and representatives of Chondrostoma s.l.). These results suggest a rapid adaptive radiation of Dactylogyrus in this geographically isolated region, closely associated with their cyprinoid hosts. Moreover, phylogenetic analysis supports that Dactylogyrus parasites colonized the Iberian Peninsula through multiple dispersion events.

Haliotrema aurigae (Yamaguti, 1968) Plaisance, Bouamer & Morand, 2004, in ornamental reef fish imported into Brazil / Haliotrema aurigae (Yamaguti, 1968) Plaisance, Bouamer & Morand, 2004, em peixe ornamental de recife importado para o Brasil

Abstract More than 1.450 marine fish species are commercialized as ornamental fish and approximately 90% of these are wild-caught. Rainford's butterflyfish, Chaetodon rainfordi (McCulloch, 1923), is endemic to the western Pacific. This fish species belongs to one of the main ornamental fish families imported into Brazil. Haliotrema is a genus of the family Dactylogyridae. Species of this genus have very interesting host associations and geographic distributions. The aim of this study was to report on occurrences of exotic Haliotrema aurigae in diseased Rainford butterflyfish that were imported to Brazil. One Rainford's butterflyfish with suspected parasitic disease was euthanized and subjected to skin and gill scraping. The parasite specimens were mounted on semi-permanent slides with Hoyer's solution for morphological analysis of sclerotized structures. The hard-sclerotized structures of these specimens were compared and were identified as those of Haliotrema aurigae (Yamaguti, 1968). These results emphasize the importance of implementation of correct control measures at the country's borders, to avoid the introduction of exotic parasites. In addition, it can be emphasized that the easy adaptation of this parasite to new environments is a concern for ornamental fish farmers.

Resumo Mais de 1.450 espécies de peixes marinhos são comercializados como peixes ornamentais e, aproximadamente, 90% são extraídos na natureza. O peixe borboleta Rainford, Chaetodon rainfordi (McCulloch, 1923), é endêmico no Pacífico Ocidental. Esta espécie de peixe pertence a uma das principais famílias importadas para o Brasil. Haliotrema é um gênero da família Dactylogyridae. Espécies desse gênero têm associação com hospedeiros e distribuição geográfica. O objetivo deste estudo é relatar a ocorrência de Haliotrema aurigae exótico, em peixes-borboleta doentes, que foram importados para o Brasil. Um peixe-borboleta Rainford, suspeito de estar infectado com doença parasitária, foi eutanasiado e submetido à raspagem de pele e brânquias. As amostras foram montadas em lâminas semipermanentes com Hoyer, para análise morfológica de estruturas esclerotizadas. A morfologia e as estruturas esclerotizadas duras das amostras foram comparadas e identificadas como Haliotrema aurigae (Yamaguti, 1968). Esses resultados enfatizam a importância da implementação de medidas de controle pós-fronteira para evitar a introdução de parasitas exóticos no país. Além disso, pode-se enfatizar que a fácil adaptação do parasita a um novo ambiente é uma preocupação para os pscicultores ornamentais.

Xiphidiocercariae from naturally infected Lymnaea columella (Mollusca, Gastropoda) in urban area: morphology and ultrastructure of the larvae and histological changes in the mollusc host / Xifidiocercárias obtidas em Lymnaea columella (Mollusca, Gastropoda) naturalmente infectadas em área urbana: morfologia e ultraestrutura da larva e alterações histológicas do molusco hospedeiro

Abstract Urban agriculture is very common in the cities, as Rio de Janeiro and adjacencies, being important as economic activity. However, this practice can create appropriate conditions for establishment and maintenance of life cycle of many parasites. Lymneid snails can act as intermediate hosts of many trematodes species, including those that infect humans and wild and domestic. In the present study, the snail Lymnaea columella was collected from an urban watercress plantations and the morphology of cercariae released by them was analyzed by light and scanning electron microscopy. The specimens were identified as xiphidiocercariae, belonging to the Cercariae Ornatae group, of the order Plagiorchiiformes. Histological examination of the digestive gland of the infected snails revealed the presence of developing sporocysts, with hemocitary infiltration and metaplasia in the epithelial tissue.

Resumo Agricultura urbana é muito comum nas cidades, como Rio de Janeiro e adjacências, sendo uma importante atividade econômica de subsistência. No entanto, esta prática pode criar condições adequadas para o estabelecimento e manutenção do ciclo de vida de muitos parasitos. Os moluscos limneídeos podem atuar como hospedeiros intermédios de muitas espécies de trematódeos, incluindo aqueles que infectam humanos e animais selvagens e domésticos. No presente estudo, o molusco Lymnaea columella foi coletado de plantações urbanas de agrião e a morfologia das cercárias liberadas por eles foi analisada por microscopia eletrônica de varredura leve e de varredura. As larvas foram identificadas como xifidiocercárias, pertencentes ao grupo das Cercariae Ornatae, Ordem Plagiorchiiformes. Análises histológicas da glândula digestiva dos moluscos infectados evidenciaram esporocistos, com formação de granuloma e metaplasia do tecido epitelial.

Xiphidiocercariae from naturally infected Lymnaea columella (Mollusca, Gastropoda) in urban area: morphology and ultrastructure of the larvae and histological changes in the mollusc host.

Urban agriculture is very common in the cities, as Rio de Janeiro and adjacencies, being important as economic activity. However, this practice can create appropriate conditions for establishment and maintenance of life cycle of many parasites. Lymneid snails can act as intermediate hosts of many trematodes species, including those that infect humans and wild and domestic. In the present study, the snail Lymnaea columella was collected from an urban watercress plantations and the morphology of cercariae released by them was analyzed by light and scanning electron microscopy. The specimens were identified as xiphidiocercariae, belonging to the Cercariae Ornatae group, of the order Plagiorchiiformes. Histological examination of the digestive gland of the infected snails revealed the presence of developing sporocysts, with hemocitary infiltration and metaplasia in the epithelial tissue.

Intermediate host switches drive diversification among the largest trematode family: evidence from the Polypipapiliotrematinae n. subf. (Opecoelidae), parasites transmitted to butterflyfishes via predation of coral polyps.

Podocotyloides stenometra Pritchard, 1966 (Digenea: Opecoelidae) is the only trematode known to infect anthozoan corals. It causes disease in coral polyps of the genus Porites Link (Scleractinia: Poritidae) and its life-cycle depends on ingestion of these polyps by butterflyfishes (Perciformes: Chaetodontidae). This species has been reported throughout the Indo-Pacific, from the Seychelles to the Galápagos, but no study has investigated whether multiple species are involved. Here, we recollect P. stenometra from its type-host and type-locality, in Hawaiian waters, and describe four new species from examination of 768 butterflyfishes from French Polynesia. On the basis of morphology, phylogeny and life-history, we propose Polypipapiliotrema Martin, Cutmore & Cribb n. gen. and the Polypipapiliotrematinae Martin, Cutmore & Cribb n. subf., for P. stenometra (Pritchard) n. comb., P. citerovarium Martin, Cutmore & Cribb n. sp., P. hadrometra Martin, Cutmore & Cribb n. sp., P. heniochi Martin, Cutmore & Cribb n. sp., and P. ovatheculum Martin, Cutmore & Cribb n. sp. Given the diversity uncovered here and the ubiquity, abundance and diversity of butterflyfishes on coral reefs, we predict that Polypipapiliotrema will prove to comprise a rich complex of species causing disease in corals across the Indo-Pacific. The unique life-cycle of these taxa is consistent with phylogenetic distinction of the group and provides evidence for a broader basis of diversification among the family. We argue that life-cycle specialisation, in terms of adoption of disparate second intermediate host groups, has been a key driver of the diversification and richness of the Opecoelidae, the largest of all trematode families and the group most frequently encountered in coral reef fishes.

Experimental avian philophthalmosis: Evaluation of diagnosis and treatment of chickens infected with Philophthalmus gralli (Trematoda: Philophthalmidae).

The trematodes of the genus Philophthalmus are eye flukes that cause damage to ocular structures of animals and humans. Despite the increasing number of cases reported in birds, studies related to the diagnosis of subclinical philophthalmosis are lacking, and there are no effective therapeutic regimens available. In the present study, we evaluated the diagnosis and treatment of philophthalmosis in specific pathogen-free chickens (Gallus gallus domesticus) experimentally infected with Philophthalmus gralli. Four chickens were inoculated with metacercariae of P. gralli (20 per eye) obtained from cercariae emerged from naturally infected Melanoides tuberculata. From 90 days post-infection, the chickens were subjected to direct ophthalmic examination (DOE) and conjunctival sac lavage (CSL). The latter technique consisted of lavage of each eye with 200 µL sterile saline solution and subsequent microscopical examination of the collected fluid for the presence of eggs of P. gralli. The anthelminthic treatment protocols included praziquantel (PZQ) at 10, 50, or 100 mg/kg (single dose given intramuscularly), or fenbendazole (FBZ) at 50 mg/kg (three doses at 24 h-intervals given per os). The treatment protocols were performed at 14 day-intervals between each dosage of PZQ. Chickens developed a minimum of one to more than five adult P. gralli per eye, except for one chicken that had a single eye with one parasite. No ocular clinical signs or changes in behavior were noted in any chickens. DOE and CSL were considered techniques with similar sensitivity for the diagnosis of avian philophthalmosis. The data suggested that PZQ and FBZ, at the dosages and schedules employed, are not effective for the complete elimination of P. gralli. CSL is proposed as a complementary technique for the diagnosis and monitoring of philophthalmosis post-treatment, especially in subclinical cases. The evaluation of new protocols, routes of administration, and anthelmintic drugs are needed for successful pharmacological treatment of philophthalmosis.

Comparative immunological study of the snail Physella acuta (Hygrophila, Pulmonata) reveals shared and unique aspects of gastropod immunobiology.

The freshwater snail Physella acuta was selected to expand the perspective of comparative snail immunology. Analysis of Physella acuta, belonging to the Physidae, taxonomic sister family to Planorbidae, affords family-level comparison of immune features characterized from Biomphalaria glabrata, the model snail often used to interpret general gastropod immunity. To capture constitutive and induced immune sequences, transcriptomes of an individual Physella acuta snail, 12 h post injection with bacteria (Gram -/+) and one sham-exposed snail were recorded with 454 pyrosequencing. Assembly yielded a combined reference transcriptome containing 24,288 transcripts. Additionally, genomic Illumina reads were obtained (∼15-fold coverage). Recovery of transcripts for two macin-like antimicrobial peptides (AMPs), 12 aplysianins, four LBP/BPIs and three physalysins indicated that Physella acuta shares a similar organization of antimicrobial defenses with Biomphalaria glabrata, contrasting a modest AMP arsenal with a diverse set of antimicrobial proteins. The lack of predicted transmembrane domains in all seven Physella acuta PGRP transcripts supports the notion that gastropods do not employ cell-bound PGRP receptors, different from ecdysozoan invertebrates yet similar to mammals (vertebrate deuterostomes). The well-documented sequence diversification by Biomphalaria glabrata FREPs (immune lectins comprising immunoglobulin superfamily domains and fibrinogen domains), resulting from somatic mutations of a large FREP gene family is hypothesized to be unique to Planorbidae; Physella acuta revealed just two bonafide FREP genes and these were not diversified. Furthermore, the flatworm parasite Echinostoma paraensei, confirmed here to infect both snail species, did not evoke from Physella acuta the abundant expression of FREP proteins at 2, 4 and 8 days post exposure that was previously observed from Biomphalaria glabrata. The Physella acuta reference transcriptome also revealed 24 unique transcripts encoding proteins consisting of a single fibrinogen-related domain (FReDs), with a short N-terminal sequence encoding either a signal peptide, transmembrane domain or no predicted features. The Physella acuta FReDs are candidate immune genes based on implication of similar sequences in immunity of bivalve molluscs. Overall, comparative analysis of snails of sister families elucidated the potential for taxon-specific immune features and investigation of strategically selected species will provide a more comprehensive view of gastropod immunity.

A new genus and two new species of dactylogyrid monogeneans from gills of Neotropical catfishes (Siluriformes: Doradidae and Loricariidae).

A new genus of dactylogyrid monogeneans (Ancyrocephalinae), Paracosmetocleithrum n. gen., is erected to accommodate P. trachydorasi n. sp. from Trachydoras paraguayensis (Siluriformes: Doradidae) in the Upper Paraná River basin, Brazil. The new genus differs from Neotropical dactylogyrids in the presence of a well-developed ornamentation in the middle portion of the ventral bar, and a sclerotized patch on the surface of the dorsal bar with an inconspicuous medial process that possesses two submedial projections arising from the tapered ends of this patch. In addition, Demidospermus rhinelepisi n. sp. is described from Rhinelepis aspera (Siluriformes: Loricariidae). The new species, which is the fifth species of the genus described from loricariids, can be differentiated from congeners by the possession of a sclerotized patch attached to the middle portion of the ventral bar, and by morphology of the accessory piece, which presents broad ends, tapering in the centre, rounded proximal end, distal end folding on both sides with folds extending to approximately ¾ of the accessory piece length. Molecular data on both new species are also provided and species composition of Demidospermus, recently revealed as polyphyletic by molecular studies including the present one, is discussed.

Digenea parasites of Acestrorhynchus falcirostris (Osteichthyes, Acestrorhynchidae) in the state of Amazonas, Brazil / Digenea parasitos de Acestrorhynchus falcirostris (Osteichthyes, Acestrorhynchidae) no estado do Amazonas, Brasil

Abstract This study presents the helminthofauna of digenean parasites of Acestrorhynchus falcirostris in the state of Amazonas (Brazil). Eight species belonging to four families were recovered: Metacercariae of Austrodiplostomum compactum (Diplostomidae) and Clinostomum marginatum (Clinostomidae) and mature specimens of Bellumcorpus majus, Prosorhynchoides carvajali, Rhipidocotyle santanaensis (Bucephalidae); Prosthenhystera obesa (Callodistomidae); Genarchella genarchella (Derogenidae) and Phyllodistomum spatula (Gorgoderidae). Examining specimens belonging to the genus Bellumcorpus collected from A. falcirostris, were observed a great variation in the size and shape of testes, which also could be observed in the type specimens of Bellumcorpus majus and B. schubarti. Considering the similar morphology and morphometric characteristics of both species, in this paper B. schubarti is considered synonym of B. majus. Acestrorhynchus falcirostris is a new host records for all these species of digenean, except to A. compactum and C. marginatum. Prosorhynchoides carvajali is referred for the first time in Brazil.

Resumo Esse estudo apresenta a fauna helmintológica de Digenea parasitos de Acestrorhynchus falcirostris no estado do Amazonas. Oito espécies pertencentes a quatro famílias foram estudadas: Metacercarias de Austrodiplostomum compactum (Diplostomidae) e Clinostomum marginatum (Clinostomidae) e espécimes adultos de Bellumcorpus majus, Prosorhynchoides carvajali, Rhipidocotyle santanaensis (Bucephalidae); Prosthenhystera obesa (Callodistomidae); Genarchella genarchella (Derogenidae) e Phyllodistomum spatula (Gorgoderidae). Examinando espécimes pertencentes ao gênero Bellumcorpus coletados de A. falcirostris, foi observada uma grande variação no tamanho e forma dos testículos, que também pode ser observada nos espécimes tipo de Bellumcorpus majus e B. schubarti. Considerando a morfologia e características morfométricas similares de ambas as espécies, neste artigo, B. schubarti é considerado sinônimo de B. majus. Acestrorhynchus falcirostris representa um novo hospedeiro para todas essas espécies de Digenea, exceto para A. compactum e C. marginatum. Prosorhynchoides carvajali é referido pela primeira vez no Brasil.

Low virulence potential and in vivo transformation ability in the honey bee venom treated Clinostomum complanatum.

The helminth parasites possess great capabilities to adapt themselves within their hosts and also develop strategies to render the commonly used anthelmintics ineffective leading to the development of resistance against these drugs. Besides using anthelmintics the natural products have also been tested for their anti-parasitic effects. Therapeutic efficacy of honey bee venom (HBV) has been tested in various ailments including some protozoal infections but very little is known about its anthelmintic properties. To investigate the anthelmintic effect of HBV the excysted progenetic metacercariae of Clinostomum complanatum, a heamophagic, digenetic trematode with zoonotic potential, infecting a wide variety of hosts, were obtained from Trichogaster fasciatus, a forage fish, which serves as the intermediate host. The metacercarial worms were in vitro incubated in RPMI-1640 medium containing HBV along with the controls which were devoid of HBV for the analysis of worm motility, enzyme activity, polypeptide profile and surface topographical changes. The motility of the worms was significantly reduced in a time dependent manner with an increase in the concentration of HBV. Following incubation of worms the release of cysteine proteases was inhibited in the presence of HBV as revealed by gelatine substrate gel zymography. As well as the polypeptide profile was also significantly influenced, particularly intensity/expression of Mr 19.4 kDa, 24 kDa and 34 kDa was significantly reduced upon HBV treatment. The HBV treatment also inhibited antioxidant enzyme, superoxide dismutase (SOD) and Glutathione-S-transferase (GST) significantly (p < 0.05) in the worms. The scanning electron microscopy of the HBV treated worms revealed tegumental disruptions and erosion of papillae as well as spines showing vacuolation in the tegument. The HBV treated worms also showed a marked decline in the transformation rate when introduced into an experimental host which further reflect the anthelmintic potential of HBV.

An integrative taxonomic study of Pavanelliella spp. (Monogenoidea, Dactylogyridae) with the description of a new species from the nasal cavities of an Amazon pimelodid catfish.

The present study is an integrative taxonomic analysis of Pavanelliella spp. (Monogenoidea, Dactylogyridae), and describes a new species from the nasal cavities of the Amazonian pimelodid catfish Brachyplatystoma rousseauxii (Siluriformes Pimelodidae) from the Tapajós River (Amazon Basin, Pará state, Brazil). Pavanelliella jarii sp. n. is characterized by the presence of 3-4 rings in the male copulatory organ, the absence of rings around the vaginal atrium and by its sinuous vaginal canal, which sometimes forms 0.5-1 rings in the distal portion. The sequencing of the small subunit ribosomal DNA (ssrDNA) and internal transcribed spacer 1 (ITS-1) of three species of Pavanelliella, Vancleaveus cicinnus, and an undetermined dactylogyrid allowed the phylogenetic reconstruction of these dactylogyrids. The analysis indicated that P. jarii sp. n. is closely related to Pavanelliella takemotoi and Pavanelliella pavanellii, which formed a sister clade to ancylodiscoidines parasites of siluriform fish from the Oriental and Afrotropical regions. The analysis also corroborated the non-monophyly of Ancyrocephalinae, revealing that ancylodiscoidines arose between ancyrocephalines lineages, in a sister relationship to pseudodactylogyrines+marine ancyrocephalines+ancyrocephalines parasites of afrotropical perciforms+dactylogyrines. Cladistical analysis indicates that the haptoral anchor/bar complex has been lost several times in the evolutionary history of Dactylogyridae. The analysis also indicated that Dactylogyrus is polyphyletic, as Acolpenteron ureteroecetes and Dactylogyroides longicirrus arose between the three lineages formed by Dactylogyrus spp.

Tissue Lesions Due to Spirorchiid Eggs in a Loggerhead Turtle ( Caretta caretta Linnaeus 1758) from Brazil: First Report Outside of the United States.

Spirorchiids (family Spirorchiidae Stunkard 1921) are a group of flukes that inhabit the circulatory system of turtles. Infection by members of the family Spirorchiidae involves egg deposition in the host bloodstream and accumulation in tissues, which cause inflammatory reactions and embolisms, leading or contributing to the death of the host. Reports of spirorchiid egg lesions in loggerhead turtles ( Caretta caretta Linnaeus, 1758) have only been reported from U.S. hosts. In the present report a female loggerhead sea turtle was found dead on the beach in the north part of the State of Rio de Janeiro, Brazil. During gross necropsy, no parasite egg nodule was found. But the microscopic analysis revealed a mild granulomatous inflammatory process due to eggs from the family Spirorchiidae and both Langhans giant cells and foreign-body giant cells in the heart, kidneys, intestines, lungs, and spleen. The present note is the first record of tissue lesions due to spirorchiid eggs in a loggerhead sea turtle outside the United States.

European distribution for metacercariae of the North American digenean Posthodiplostomum cf. minimum centrarchi (Strigeiformes: Diplostomidae).

Metacercariae of a North American digenean Posthodiplostomum cf. minimum centrarchi (Strigeiformes: Diplostomidae), have been reported from seven localities in Europe, with cysts recorded in the mesentery and internal organs of two invasive non-indigenous fishes (Lepomis gibbosus and Micropterus salmoides) from sites in Bulgaria, the Czech Republic and Portugal. Analysis of rDNA locus ITS1-ITS2-28S confirmed a closer relationship to the American Posthodiplostomum species than the common European species P. cuticola or P. brevicaudatum. Our data indicate limited potential of this parasite for switch to local fish fauna and confirm the occurrence at distant sites across Europe, suggesting that birds as definitive parasite hosts may play an important role for parasite dispersal. Further detailed studies are needed to confirm the actual means of introduction to Europe.