Phylogenetic position of Ancyrocephalus (sensu lato) curtus Achmerov, 1952 (Monopisthocotylea, Dactylogyridae), a parasite of fish Perccottus glenii Dybowski, 1877(Gobiiformes: Odontobutidae).

The genus Ancyrocephalus sensu lato is a large assemblage of species of dactylogyrid monopisthocotyleans without clear taxonomic boundaries. Despite an urgent need for revision, only three representatives of this taxon have been molecularly characterised so far. We found specimens of Ancyrocephalus curtus, a previously non-genotyped species, in gills of Perccottus glenii caught in the River Syumnyur, Amur Basin, Russia. The aim of this study was to assess the phylogenetic position of this parasite using partial sequences of 28S rRNA gene. In the phylogenetic tree, A. curtus appeared as a sister taxon to the dactylogyrine genus Gobioecetes. The new molecular evidence supports the hypothesis about the non-monophyletic status of Ancyrocephalus sensu lato.

Two new Neotetraonchus species (Dactylogyridea, Dactylogyridae) parasitising the Peruvian sea catfish Galeichthys peruvianus (Siluriformes, Ariidae), including molecular data.

As part of a parasitological survey, several specimens of two new monopisthocotylean species, Neotetraonchus celsomanueli sp. nov. and N.peruvianus sp. nov. (Dactylogyridea, Dactylogyridae), were collected from the gill filaments of the Peruvian sea catfish Galeichthys peruvianus (Siluriformes, Ariidae) off Puerto Pizarro, Tumbes region, Peru. Neotetraonchus celsomanueli sp. nov. is characterised by an MCO with a T-shaped distal end and an accessory piece that is ribbed and expanded proximally with a worm-shaped termination. Neotetraonchus peruvianus sp. nov. is typified by its MCO, which has a sledgehammer-shaped distal end and an accessory piece with a claw-shaped distal end. Additionally, N.peruvianus sp. nov. is characterised by its jellyfish-shaped onchium. A partial 28S rDNA sequence was obtained from N.celsomanueli sp. nov., and a phylogenetic analysis was conducted. This analysis revealed the phylogenetic position of Neotetraonchus celsomanueli sp. nov. within a clade comprising monopisthocotylean parasites of diadromous and marine ariid catfishes, including Hamatopeduncularia spp., Chauhanellus spp., Thysanotohaptor Kritsky, Shameem, Kumari & Krishnaveni, , and Neocalceostomoides spinivaginalis Lim, 1995. This finding brings the number of known Neotetraonchus species to seven and represents the first described Neotetraonchus species infecting marine catfishes from Peru.

Description of two new species of dactylogirids (Monogenoidea: Dactylogyridae) from Mylossoma albiscopum (Cope, 1872) (Characiformes: Serrasalmidae) from the Peruvian Amazonia.

INTRODUCTION: Two new dactylogyrid monogeneans, Anacanthorus cultro n. sp. and Notozothecium palometae n. sp., are described based on specimens collected from the gill filaments of Mylossoma albiscopum (Cope, 1872) (Characiformes: Serrasalmidae), a pelagic and herbivore teleost collected in the Tigre river, Loreto, Peru. MATERIALS AND METHODS: Some monogeneans were stained with Gomori's trichrome and mounted in Canada Balsam to determine internal soft structures. Others were cleared in Hoyer's medium for the study of sclerotized structures. Drawings were made using a drawing tube and a microprojector. RESULTS: Anacanthorus cultro n. sp. is characterized by the presence of a rod-shaped male copulatory organ (MCO) lacking featherlike structures, and a knife-shaped accessory piece with a submedial knob. Notozothecium palometae n. sp. can be distinguished from all congeners by its MCO with a subbasal spur and an accessory piece with inverted hammer shaped. CONCLUSIONS: This is the first data on the parasites of M. albiscopum, a popular fish in local markets. Anacanthorus cultro n. sp. is the twenty-fifth documented species of the genus in Peru, while N. palometae n. sp. represents the seventh species of the genus known to infect freshwater fish species in Peru.

Monogenoidea Communities Differ Between Male Morphotypes of Bluegill Sunfish (Lepomis macrochirus).

PURPOSE: Bluegill sunfish (Lepomis macrochirus) are a North American sport fish that exhibit two different male morphotypes. Alpha-males are large, colorful, territorial, and have significant parental investment, while ß-males are small, drab, and have two reproductive phenotypes, neither of which involves parental investment. Due to the two different reproductive strategies, the level of interaction between congenerics varies, which may impact parasites that are spread via close contact, such as Monogenoidea that infect the gills. Monogeneans are ectoparasites on the gills and skin of fish hosts that may cause significant pathology in high numbers and be an indicator of host behavior and interaction between hosts. METHODS: In this study, 328 L. macrochirus (106 α-males, 92 ß-males, and 130 females) were necropsied from 8 lakes and ponds in northwestern Virginia to identify and enumerate monogenean parasites from the gills. RESULTS: Alpha-males had a significantly greater parasite abundance and species richness compared to ß-males. This may be due to the increased size and surface area of gills in α-males, increased interaction with females during mating, and stationary behavior when guarding nests, which enhanced the chances of α-males contracting the parasites. This also led to significant differences in the monogenean communities infecting the two morphotypes, which were also significantly influenced by the size of the hosts. CONCLUSIONS: It is important in future studies regarding parasitism that behavioral morphotypes within a sex, such as α-male and ß-male L. macrochirus in this study, be treated separately as behavioral and morphometric differences between them can potentially lead to differences in parasitism.

Species of Dactylogyridae (Monogenoidea, Polyonchoinea) from the gills of haemulid and lutjanid fishes (Perciformes) from the Pacific coast of Mexico.

Examination of the gill lamellae of the Panama grunt Rhencus panamensis (Steindachner) (Haemulidae), golden snapper Lutjanus inermis (Peters), and yellow snapper Lutjanus argentiventris (Peters) (Lutjanidae) (Perciformes) from the coast of the Guerrero State (eastern Tropical Pacific) of Mexico revealed 5 species of Monogenoidea: Euryhaliotrema disparum n. sp. on R. panamensis; Haliotrematoides uagroi n. sp. on L. inermis; and E. anecorhizion Kritsky & Mendoza-Franco, 2012, E. fastigatum (Zhukov, 1976) Kritsky & Boeger, 2002, and E. paracanthi (Zhukov, 1976) Kritsky & Boeger, 2002 on L. argentiventris. Specimens found on R. panamensis were assigned within Euryhaliotrema as a new species possessing the atypical morphology of the male copulatory organ (i.e., a coiled tube with clockwise rings). Haliotrematoides uagroi n. sp. differs from Haliotrematoides striatohamus (Zhukov, 1981) Mendoza-Franco, Reyes-Lizama & Gonzalez-Solis, 2009 from Haemulon spp. (Haemulidae) from the Caribbean Sea (Mexico) in having inner blades on the distal shafts of the ventral and dorsal anchors. The present paper represents the first finding of a species of Euryhaliotrema (E. disparum n. sp.) on a species of Rhencus and the second species on a haemulid host, and H. uagroi n. sp. as the first monogenoidean species described on L. inermis. Euryhaliotrema anecorhizion, E. fastigatum, and E. paracanthi on L. argentiventris in the Pacific coast of Mexico represent new geographical records.

Helminth and ectoparasitic faunas of the Harris's hawk, Parabuteo unicinctus (Accipitriformes: Accipitridae), in Chile: new data on host-parasite associations for Neotropical raptors / Helmintos e ectoparasitas do gavião-asa-de-telha (Accipitriformes: Parabuteo unicinctus) no Chile: novas associações parasita-hospedeiro para os rapinantes neotropicais

Abstract Birds of prey harbor a wide spectrum of various parasites, mostly with a heteroxenous life cycle. However, most reports on their parasites come from Europe. Although the Harris's hawk (Parabuteo unicinctus) is a widespread species in America, parasitological surveys on this hawk are mostly focused on coprological findings and ectoparasites, with poor attention paid to helminths. The aim of this study was to gather new and additional data on host-parasite associations for the Harris's hawk. Twenty-nine birds from central and southern Chile were necropsied. Further, nine birds from a rehabilitation center and 22 museum specimens were inspected for ectoparasites. Sixty-eight percent of birds hosted at least one parasite species. Four lice species, one mite species and eight helminth species (five nematodes, two platyhelminthes and one acanthocephalan) were recorded. Parasitic lice Colpocephalum nanum and Nosopon chanabense, and a nematode Cyathostoma (Hovorkonema) americana were recorded for the first time in raptors from the Neotropics. A feather mite, Pseudalloptinus sp., nematodes, Physaloptera alata and Microtetrameres sp., and a trematode Neodiplostomim travassosi, were recorded for the first time in Chile. The presence of diverse heteroxenous helminths reported here in the Harris's hawk could be explained by the generalist diet of this raptor.

Resumo As aves de rapina representam uma fonte importante de parasitas heteroxenos. Porém, a maioria dos relatos são da Europa. O gavião-asa-de-telha (Parabuteo unicinctus) é uma espécie amplamente distribuída no continente Americano, porém estudos parasitológicos nessas aves têm documentado achados coprológicos e ectoparasitas, com poucos relatos sobre endoparasitas como helmintos. Por essa razão, o objetivo deste estudo foi descrever novas associações parasita-hospedeiro para o gavião-asa-de-telha e rapinantes neotropicais. Vinte nove aves provenientes do centro e sul do Chile foram submetidas à necropsia. Por outro lado, nove aves de um centro de reabilitação e 22 espécimes de museu foram inspecionados em busca de ectoparasitas. Do total de aves, 68,3% foram identificadas como portadoras de pelo menos uma espécie de parasita. Quatro espécies de piolhos, um ácaro e oito helmintos (cinco nematoides, dois platelmintos e um acantocéfalo) foram registrados. Os piolhos Colpocephalum nanum, Nosopon chanabense e o nematóide Cyathostoma (Hovorkonema) americana são reportados pela primeira vez em rapinantes neotropicais. Colpocephalum nanum, N. chanabense, Pseudalloptinus sp., Physaloptera alata, Microtetrameres sp., C. (H.) americana e Neodiplostomim travassosi, são reportados pela primeira vez no Chile. A diversidade de helmintos heteróxenos, identificados neste trabalho, poderia ser explicada devido à dieta geralista do gavião-asa-de-telha.

Urocleidus sayani n. sp. (Monogenea: Dactylogyridae) from Gills of Pirate Perch (Aphredoderus sayanus).

Urocleidus sayani n. sp. is described from the gills of pirate perch (Aphredoderus sayanus) in the Wisconsin backwaters of the upper Mississippi River and was found in samples from the Southeastern United States. Urocleidus sayani n. sp. is the second monogenean described from the pirate perch and the first for this host within Dactylogyridae. The description includes a partial 18S rRNA gene sequence (623 bp), filling a void in sequence data from North American monogeneans.

First Record of a Polystome from Alligator Snapping Turtle, Macrochelys temminckii (Cryptodira: Chelydridae) or Mississippi; with Comments on "Neopolystoma orbiculare (Stunkard, 1916)" and Its Junior Subjective Synonyms.

Herein, we describe several newly-collected specimens of Neopolystoma cf. orbiculare from the urinary bladder of 2 alligator snapping turtles, Macrochelys temminckii (Troost in Harland, 1835) (Cryptodira: Chelydridae Gray, 1831) from Comet Lake (30°35'46.94″N, 88°36'3.12″W), Pascagoula River, Mississippi. Our specimens differed from all previous descriptions of N. orbiculare and its junior subjective synonyms by the combination of having intestinal ceca adorned with triangular pockets and that terminate dorsal to the haptor, distinctive hooklets each having a handle and guard of approximately equal length and having a much longer and curved blade, 16 genital coronet spines that each possess 1-2 flanges per spine, pre-testicular vaginal pores, and vaginal ducts that are anterior to the junction of the oviduct and genito-intestinal canal. Some of our specimens were enantiomorphic (4 and 3 had a dextral and sinistral ovary, respectively). Nucleotide sequences (large subunit ribosomal DNA [28S], small subunit ribosomal DNA [18S], and cytochrome oxidase subunit 1 mitochondrial gene [COI]) for our specimens were most similar to GenBank sequences ascribed to N. orbiculare. Single-gene and concatenated phylogenetic analyses confirmed that NeopolystomaPrice, 1939 is polyphyletic and that our isolates share a recent common ancestor with those ascribed to N. orbiculare. This is the first record of a polystomatid from Mississippi, from the Pascagoula River, and from the alligator snapping turtle (and only the second species of Neopolystoma reported from any snapping turtle).

On Temnocephala axenos Monticelli, 1898 (Platyhelminthes, Temnocephalida): taxonomic status and designation of a neotype.

Temnocephala axenos Monticelli, 1898 was described based on specimens from an unidentified host collected in Blumenau, Santa Catarina, Brazil. Information about type locality was imprecise and the host was later identified as Aegla laevis (Latreille, 1818). However, it is known that A. laevis is not present on the eastern side of the Andes. Also, only histological preparations from one specimen studied by Monticelli are currently available in the Museum für Naturkunde Berlin, but it showed none of the taxonomic characters needed for the characterization of the species. Although the updated description of the species based on Uruguayan specimens, neither the author nor the several previous studies about the species showed a search for the type material, a resolution for the misidentification of the type host or the imprecise type locality due to the subsequent geographical division of the municipality cited in the description. The Uruguayan specimens were not even geographically close to the type locality and a neotype was not designed to validate the species' taxonomic status again. Specimens from Santa Catarina and Paraná States, Brazil, were studied, as well as restudied Argentinean specimens. The new data were compared with the update description of the species. The historical background and the discussion about geographical origins and hosts of the species, as well as a designation of a neotype, allow comparative material of the type locality and type host to exist, eliminating doubts about the identification of T. axenos.

Eye to eye: classification of conjunctival sac polystomes (Monogenea: Polystomatidae) revisited with the description of three new genera Apaloneotrema n. g., Aussietrema n. g. and Fornixtrema n. g.

Polystomes (Monogenea: Polystomatidae) of freshwater turtles are currently represented by five genera, namely Neopolystoma, Polystomoides, Polystomoidella, Uropolystomoides and Uteropolystomoides. These parasites can infect the urinary, oral and/or the conjunctival sac systems of their hosts, showing strict site specificity. A recent phylogenetic study showed that the two most diverse genera within chelonian polystomes, i.e. Neopolystoma and Polystomoides, are not monophyletic. Furthermore, polystomes infecting the conjunctival sacs of their host, except for one species, formed a robust lineage. A fusiform egg shape has been reported for conjunctival sac polystomes and it was assumed that this characteristic could be a good character for the systematics of polystomes. Our objective in the present work was, therefore, to study more in depth the morphology of polystomes collected from the conjunctival sacs of chelonians to find characters defining a putative new genus. To achieve this objective, more specimens were collected in 2018 and 2019 from turtles sampled in North Carolina and Florida (USA) to extend taxon sampling for the phylogenetic analysis. Morphological characters of relevant polystome specimens were re-examined from several collections from Asia, Australia, Europe, South Africa, South America and North America. Based on a Bayesian tree inferred from the analysis of four concatenated genes, namely 12S, 18S, 28S and COI, polystomes found in the conjunctival sacs were grouped in three distinct lineages, the first one including a single species infecting an Australian pleurodire turtle; the second one including eleven species infecting cryptodire turtles of South America, North America and Asia; and the last one including a single species infecting a softshell cryptodire turtle of North America. Based on observations of live specimens by Dr. Sylvie Pichelin and our morphological analysis, the conjunctival sac polystomes from Australian turtles are small, cannot extend their body significantly, have a spherical ovary and egg, have a large genital bulb and possess latero-ventral vaginae at the level of the testis. Based on observations of live specimens and morphological analysis of whole mounted specimens, polystomes of the second lineage share the following morphological characteristics: the ability to stretch out and double their length, a long oval ovary, a separate egg-cell-maturation-chamber, fusiform to diamond-shaped eggs with acute tips, small genital bulb and vaginae peripheral on the side of the body at the level of the testis. The polystome species of the third lineage occupies a basal position, has the ability to stretch out and possess an elongated ovary, a large fusiform egg with rounded tips, a small genital bulb and small latero-ventral vaginae at the level of the ovary. These three distinct conjunctival sac polystome lineages are herein described as separate new genera, Aussietrema, Fornixtrema and Apaloneotrema, respectively.

Seven new species of Urocleidoides (Monogenea: Dactylogyridae) from Brazilian fishes supported by morphological and molecular data.

Seven new species of Urocleidoides from the gills and skin of nine Neotropical fish hosts (Anostomidae, Parodontidae, and Gymnotidae) are described: Urocleidoides digitabulum n. sp. on Leporinus friderici, Leporinus octofasciatus, and Megaleporinus elongatus (Anostomidae); Urocleidoides solarivaginatus n. sp. on L. friderici, L. octofasciatus, and Leporinus striatus (Anostomidae); Urocleidoides falxus n. sp. and Urocleidoides sapucaiensis n. sp. on M. elongatus; Urocleidoides tenuis n. sp. on Apareiodon piracicabae and Apareiodon affinis (Parodontidae); Urocleidoides sinus n. sp. on L. striatus, Schizodon nasutus, and Schizodon intermedius (Anostomidae); and Urocleidoides uncinus n. sp. on Gymnotus sylvius (Gymnotidae). Urocleidoides paradoxus was also found in this study on L. friderici and included in the phylogenetic analysis. Molecular data (partial 28S rDNA and mitochondrial cytochrome oxidase subunit I) were obtained for U. digitabulum n. sp., U. tenuis n. sp., U. sinus n. sp., and U. uncinus n. sp. The identification of Urocleidoides is amended herein to include all taxonomic modifications observed in this genus over time and add new characteristics observed in the species in the present study. Phylogenetic analysis revealed Urocleidoides digitabulum n. sp. and Urocleidoides sinus n. sp. (parasites of anostomids) closely related in the tree topologies. Furthermore, the new species described herein parasitized phylogenetically distant host species (Characiformes and Gymnotiformes), suggesting the effect of the dynamic process of ecological fitting.

A survey of gyrodactylid parasites on the fins of Homatula variegata in central China.

In this study, two parasites on the fins of Homatula variegata were recorded from March to September 2016. A dissection mirror was used to examine the distribution and quantity of the ectoparasitic Gyrodactylus sp. and Paragyrodactylus variegatus on the host Homatula variegata in different seasons. The present study explored possible explanations for the site specificity of gyrodactylid parasites in 442 Homatula variegata infected with 4307 Gyrodactylus sp. (species identification is incomplete, only characterized to the genus level) and 1712 Paragyrodactylus variegatus. These two gyrodactylid parasites were collected from fish fins, and the fish were harvested in China's Qinling Mountains.The results indicated that the highest number of Gyrodactylus sp., which was numerically the dominant species, appeared on the fish fins in April, while the highest number of Paragyrodactylus variegatus was found on the fish fins in March. The two parasite species appeared to be partitioned spatially, with Gyrodactylus sp. occurring more frequently on pectoral and pelvic fins, and P. variegatus occurring more frequently on caudal fins. However, Gyrodactylus sp. appeared to occur on fish of all lengths, while P. variegatus tended to occur more abundantly on shorter fish rather than on longer fish. At lower Gyrodactylus sp. infection levels (<100), the pelvic and pectoral fins were the main locations of attachment, followed by the dorsal fin. For infections of more than 100 parasites, more samples of Gyrodactylus sp. were located on the pectoral fin. For a low number of Paragyrodactylus variegatus infections (<100), the pelvic and pectoral fins were the preferred locations of attachment, followed by the caudal fin. Between April and September, there were many monogenean parasites on fish fins, and the fish size was within the range of 5-10 cm. However, when a fish was longer than 10 cm long, the number of parasites on its fins greatly decreased.

Dactylogyrus pisolabrae n. sp. (Monogenoidea: Dactylogyridae) Parasitizing the Pealip Redhorse, Moxostoma pisolabrum (Teleostei: Catostomidae), from Oklahoma, U.S.A.

A new species of monogenean, Dactylogyrus pisolabrae n. sp., was found parasitizing the gills of the Pealip Redhorse, Moxostoma pisolabrum, from Oklahoma. Dactylogyrus pisolabrae is morphologically similar to Dactylogyrus apos, Dactylogyrus atripinnei, Dactylogyrus duquesnei, and Dactylogyrus niger, all parasitizing other species of suckers, by possessing a robust, sickle-shaped male copulatory organ, but differs from these and all other species of North American Dactylogyrus by possessing 2 unique wing-like projections opposite each other on the proximal portion of the accessory piece. Dactylogyrus pisolabrae represents the first monogenean reported from the Pealip Redhorse.

Morphologic and molecular characterization of Gyrodactylus cyclopteri Scyborskaja, 1948, from Cyclopterus lumpus L., 1758.

Interest and use of the lumpfish Cyclopterus lumpus L., 1758, as a cleaner fish in salmon aquaculture has grown significantly over the past 10 years. This has resulted in an explosion of new hatcheries to supply juveniles to the salmon industry. Until recently, these hatcheries have utilized a significant amount of wild broodstock to source the eggs required. Importation of wild fish into aquaculture systems brings an inherent risk of introducing pathogens into the culture systems. Gyrodactylus cyclopteri Scyborskaja, 1948, was found on local wild collected lumpfish that were brought in to start a captive lumpfish aquaculture program in Maine. Little information on the identification or description of G. cyclopteri was available. A re-description of the parasite, supplemented with molecular data, was undertaken to facilitate future identification and support research on this parasite of an emerging, economically significant new aquaculture species.

Rhinoxenus (Dactylogyridae) parasitizing piranhas (Serrasalmidae) at its southernmost limit of distribution (Paraná River, Argentina), with the description of two new species.

Three piranha species, Serrasalmus maculatus, S. marginatus and Pygocentrus nattereri, living sympatrically in the lower Paraná River (Argentina) were examined searching for nasal monogeneans to know its diversity and distribution. Four species of monogeneans belonging to Rhinoxenus were found parasitizing the nasal cavities. Two new species are described, and new morphological data of 2 previously described species is provided. Rhinoxenus argentinensis n. sp. is characterized by having the male copulatory organ (MCO) as a coiled tube with a reel shaped-base; an elongated accessory piece articulated to base of MCO; a sinistral vagina with a sclerotized vestibule, and a sclerotized cap of the ventral anchor laterally modified forming a triangular expansion. Rhinoxenus paranaensis n. sp. is characterized by having a MCO as a coiled tube with a reel-shaped base; an accessory piece with an elongate proximal portion, a dilated distal portion with digitiform projections articulated to base of MCO; a sinistral vagina with 5-6 cuticular spine-shaped processes, and a sclerotized cap of the ventral anchor modified laterally forming a bilobate expansion. Additionally, multivariate discriminant analyses showed significant morphometric differences in the ventral anchors among Rhinoxenus species parasitizing 'piranhas '.

Diversity of Empruthotrema Johnston and Tiegs, 1992 parasitizing batoids (Chondrichthyes: Rajiformes and Myliobatiformes) from the Southwest Atlantic Ocean, with description of three new species.

During an extensive research project involving 519 specimens of batoids, including 13 species of Rajiformes and Myliobatiformes (Chondrichthyes) from the Argentine Sea, three new species of Empruthotrema were found and are described using morphologic characteristics and two molecular markers: LSU rDNA and COI mtDNA. The new species can be distinguished from their congeners by the number and distribution of the marginal loculi, the length and morphology of male copulatory organ, and the presence of eyespots. Additionally, multivariate analysis identified the dimensions of the pharynx and ejaculatory bulb as diagnostic features. Host specificity and previous records of the genus in the region are discussed. This is the first description of new species in this genus for the Southwestern Atlantic Ocean, as well as for arhynchobatid hosts.

Artyfechinostomum sufrartyfex Trematode Infections in Children, Bihar, India.

Eating raw or insufficiently cooked mollusks is a known risk factor for human echinostomiasis. We confirmed identification of Artyfechinostomum sufrartyfex trematodes as the causative agent of disease among 170 children in northern Bihar, India. We also identified the snail Pila globosa as a potential source of infections in the study area.

First record of Unibarra paranoplatensis Suriano & Incorvaia, 1995 (Dactylogyridae: Monogenea) on Sorubim lima (Siluriformes: Pimelodidae) from Brazil / Primeiro registro de Unibarra paranoplatensis Suriano & Incorvaia, 1995 (Dactylogyridae: Monogenea) em Sorubim lima (Siluriformes: Pimelodidae) do Brasil

Abstract The aim of this study was to report the first occurrence of Unibarra paranoplatensis Suriano & Incorvaia, 1995 on Sorubim lima Bloch & Schneider, 1801 from Brazil. On the gills of S. lima, U. paranoplatensis presented similar morphological and morphometric features to those described for conspecifics infesting Zungaro zungaro Humboldt, 1921 except the length, which was higher in the present study, as well as ventral bar shape that was V-shaped open, and with the upper and lower end of the rod relatively sinuous. This study expands the geographic distribution of U. paranoplatensis to Brazil, a parasite that has a wide occurrence across South America.

Resumo O objetivo deste estudo foi relatar a primeira ocorrência de Unibarra paranoplatensis Suriano & Incorvaia, 1995 em Sorubim lima Bloch & Schneider, 180 do Brasil. Nas brânquias de S. lima do Rio Acre, estado do Acre (Brasil), U. paranoplatensis apresentou características morfológicas e morfométricas similares àquelas descritas para Zungaro zungaro Humboldt, 1921; com exceção do comprimento que foi maior no presente estudo e formato da barra ventral que foi em forma de V aberto, com a extremidade superior e inferior da barra relativamente sinuosa. Este estudo amplia a distribuição geográfica de U. paranoplatensis para o Brasil, um parasito com distribuição na América do Sul.

First report of the metacestode Caulobothrium sp. in the Peruvian scallop Argopecten purpuratus from Sechura Bay, Piura, Peru.

In recent parasitological surveys performed on the Peruvian scallop, Argopecten purpuratus, from bottom cultures of Sechura Bay, Piura, Peru, free and encysted metacestodes were frequently found in their gonads. The objective of this study was to identify this metacestode, determine their prevalence and intensity and briefly assess the histopathological impact in the affected tissues. A parasitological study of 890 scallops over a 3-year period was performed in order to determine the parasite prevalence and intensity. Microscopical observation of details of the scolex and histopathological study of the affected host tissues were performed as well as molecular characterization of the parasite based on 18S and 28S rDNA sequences. The prevalence of the metacestode was 82.2% in August of 2013, 90.4% in November of 2014, and 83.1% and 85.6% in April and September of 2015, respectively. The highest average intensity (218.4) was found in spring of 2014. The histopathological study showed that plerocercoids reduced the gonadal space where the ovules develop. The molecular characterization and phylogenetic analysis revealed that the metacestodes belong to the genus Caulobothrium having high sequence similarity to Caulobothrium opisthorchis. This study constitutes the first report of Caulobothrium metacestodes in the scallop A. purpuratus.

First record of Unibarra paranoplatensis Suriano & Incorvaia, 1995 (Dactylogyridae: Monogenea) on Sorubim lima (Siluriformes: Pimelodidae) from Brazil.

The aim of this study was to report the first occurrence of Unibarra paranoplatensis Suriano & Incorvaia, 1995 on Sorubim lima Bloch & Schneider, 1801 from Brazil. On the gills of S. lima, U. paranoplatensis presented similar morphological and morphometric features to those described for conspecifics infesting Zungaro zungaro Humboldt, 1921 except the length, which was higher in the present study, as well as ventral bar shape that was V-shaped open, and with the upper and lower end of the rod relatively sinuous. This study expands the geographic distribution of U. paranoplatensis to Brazil, a parasite that has a wide occurrence across South America.