New species of Polystomoides (Monogenoidea: Polystomatidae) parasitizing the urinary bladder of a freshwater turtle in Brazil / Nova espécie de Polystomoides (Monogenoidea: Polystomatidae) parasitando a bexiga urinária de uma tartaruga de água doce no Brasil

Trachemys dorbigni is the most abundant freshwater turtle species in Rio Grande do Sul, southern Brazil. Chelonians are known to host a wide variety of pathogens, including viruses, bacteria, hemoparasites and helminths. Among these, nine genera of polystomatid flatworms (Monogenoidea; Polystomatidae) infect freshwater turtles: Apaloneotrema, Aussietrema, Fornixtrema, Manotrema, Pleurodirotrema, Polystomoidella, Polystomoides, Uropolystomoides and Uteropolystomoides. However, little is known about the biology of these parasites in the Neotropical Realm. Through investigative cystoscopy, specimens of Polystomatidae were located inside the urinary bladder of the host T. dorbigni. Retrieved specimens were fixed and stained whole mounts prepared for taxonomic identification. In the present paper, a new species of Polystomoides (Monogenoidea: Polystomatidae) parasitizing the urinary bladder of a freshwater turtle of the species T. dorbigni in Brazil is described. Polystomoides santamariensis n. sp. differs from the congeneric species on the length of the genital spines, which are longer. Given the enormous diversity of freshwater turtles around the world, it is likely that a large number of chelonian polystomatids are still unknown.(AU)

Trachemys dorbigni é a espécie de tartaruga de água doce mais abundante do Rio Grande do Sul, no Sul do Brasil. Sabe-se que os quelônios são hospedeiros de uma grande variedade de patógenos, incluindo vírus, bactérias, hemoparasitos e helmintos. Dentre estes, oito gêneros de Polystomatidae (Platyhelminthes: Monogenoidea) infectam tartarugas de água doce: Apaloneotrema, Aussietrema, Fornixtrema, Manotrema, Pleurodirotrema, Polystomoidella, Polystomoides, Uropolystomoides e Uteropolystomoides. No entanto, pouco ainda se sabe sobre a biologia destes parasitos na Região Neotropical. Durante uma citoscopia investigativa, foram observados espécimes de Polystomatidae localizados no interior da bexiga urinária de T. dorbigni. Os espécimes coletados foram fixados e corados para identificação taxonômica. No presente artigo, uma nova espécie de Polystomoides (Monogenoidea: Polystomatidae) parasitando a bexiga urinária de tartaruga de água doce da espécie T. dorbigni no Brasil é descrita. Polystomoides santamariensis n. sp. difere das demais espécies no tamanho dos espinhos genitais, que são maiores. Devido a enorme diversidade de tartarugas de água doce ao redor do mundo, é provável que um grande número de polistomatídeos de quelônios ainda seja desconhecido.(AU)

New records of Monogenoidea (Platyhelminthes) from three marine fish species from the coast of Angra dos Reis, Rio de Janeiro, Brazil

During a survey of helminth parasites, five monogenoid species were reported from marine fishes from the coast of Angra dos Reis, littoral of Rio de Janeiro State, Atlantic Ocean. A total of 810 monogenoids were collected: Pseudotagia pomadasys Hernández-Vale, Bunkley-Williams & Williams Jr, 2016, Pseudoeurysorchis travassosi Caballero & Bravo-Hollis, 1962 in Haemulopsis corvinaeformis (Steindachner, 1868) (=Pomadasys corvinaeformis), Neodiplectanum mexicanum (Mendoza-Franco, Roche & Torchin, 2008) Domingues, Diamanka & Pariselle, 2011 and Aristocleidus hastatus Mueller, 1936 in Diapterus rhombeus (Cuvier, 1829) and Acanthocercodes bullardi Kritsky & Diggles, 2015 in Polydactylus virginicus (Linnaeus, 1758). The presence of P. pomadasys, P. travassosi and A. hastatus in the Southwest Atlantic Ocean represents a new geographical distribution for these species. Haemulopsis corvinaeformis represents a new host record for P. travassosi and A. bullardi is reported in the present paper for the first time parasitizing the gills of a polynemid in South Atlantic Ocean. The findings show that they belong to species previously recorded from the same or congeneric hosts from Central America and Mexico, representing new data on hosts and geographical records.(AU)

Helminths assemblage of Trachemys dorbigni (Testudines: Emydidae) in southern Brazil: implications of anthropogenic environments and hosts genders

ABSTRACT The assemblage of helminths of Trachemys dorbigni was analyzed according two environments (rural and urban) and according to hosts gender. Thus, the helminths found were: Spiroxys contortus (Rudolphi, 1819), Falcaustra affinis (Leidy, 1856), Camallanus emydidius Mascarenhas & Müller, 2017, Dioctophyme renale (Goeze, 1782) (larvae), Eustrongylides sp. (larvae) (Nematoda), Telorchis corti (Stunkard, 1915), Telorchis achavali Mañé-Garzón & Holcman-Spector, 1973, Telorchis spp. (Digenea), Polystomoides rohdei Mañé-Garzón & Holcman-Spector,1968 and Neopolystoma sp. (Monogenoidea). Parasitological indices suggests that S. contortus, F. affinis, C. emydidius, T. corti and P. rohdei are species common in helminth assemblage of T. dorbigni in southern Brazil. Infection by Dioctophyme renale is typical of the urban area and suggest relation with eutrophication process and feedback of parasitic cycle in the freshwater urban environment. Parasitological indices of Neopolystoma sp. and T. achavali suggest to be occasional infections; whereas infection by Eustrongylides sp. could be considered accidental. About Telorchiidae, there was no co-occurrence of the species of this group for the examined hosts. In relation to hosts gender, it was observed that infections by S. contortus, F. affinis, C. emydidius and T. corti had higher rates in females, showing a more intimate association with the females of T. dorbigni. The results suggest that human impact on the environment could affect the infrapopulacional dynamics of parasite species influencing the presence and rates of infection of helminths or exacerbating heterogeneities related to hosts gender.

RESUMO A assembleia de helmintos de Trachemys dorbigni foi analizada de acordo com dois ambientes (rural e urbano) e de acordo com o gênero sexual dos hospedeiros. Os helmintos encontrados foram: Spiroxys contortus (Rudolphi, 1819), Falcaustra affinis (Leidy, 1856), Camallanus emydidius Mascarenhas & Müller, 2017, Dioctophyme renale (Goeze, 1782) (larva), Eustrongylides sp. (larva) (Nematoda), Telorchis corti (Stunkard, 1915), Telorchis achavali Mañé-Garzón & Holcman-Spector, 1973, Telorchis spp. (Digenea), Polystomoides rohdei Mañé-Garzón & Holcman-Spector,1968 and Neopolystoma sp. (Monogenoidea). Os indices parasitológicos sugerem que S. contortus, F. affinis, C. emydidius, T. corti e P. rohdei são espécies comuns da assembleia de helmintos de T. dorbigni no extremo sul do Brasil. A infecção por Dioctophyme renale é tipica da area urbana e sugere estar relacionada com os processos de eutrofização e a retroalimentação do ciclo parasitário no ambiente aquático urbano. Os indices parasitológicos de Neopolystoma sp. e T. achavali sugerem que a infecção por estes seja occasional; a infecção por Eustrongylides sp. pode ser considerada acidental. Não houve co-ocorrência entre as espécies de Telorchiidae. Em relação ao gênero sexual, observou-se que as infecções por S. contortus, F. affinis, C. emydidius e T. corti apresentaram taxas mais elevadas nas fêmeas, mostrando uma associação mais íntima com as fêmeas de T. dorbigni. Os resultados sugerem que o impacto humano sobre o ambiente pode afetar a dinâmica das infrapopulações dos helmintos parasitos, influenciando a presença e os índices de infecção de helmintos ou exacerbando heterogeneidades relacionadas ao gênero sexual dos hospedeiros.

Three new species of Urocleidoides (Monogenoidea: Dactylogyridae) parasitizing characiforms (Actinopterygii: Characiformes) in Tocantins River, states of Tocantins and Maranhão, and new record for U. triangulus in Guandu River, state of Rio de Janeiro, Brazil

ABSTRACT Three new species of Urocleidoides Mizelle & Price, 1964 are described from the gills of characiform fishes in the Tocantins River and its tributaries. Urocleidoides boulengerellae sp. nov. is described from Boulengerella cuvieri (Spix & Agassiz, 1829) and differs from all its congeners by the dorsal bar with a long posteromedial projection; male copulatory organ with 2-3 counterclockwise rings and a base with a flange; an accessory piece comprising a robust Y-shaped unit and a sheath-like unit; and a highly sclerotized vaginal canal. Urocleidoides paratriangulus sp. nov., described from Psectrogaster amazonica Eigenmann & Eigenmann, 1889, Cyphocharax gouldingi Vari, 1992, Caenotropus labyrinthicus (Kner, 1858) and Mylesinus paucisquamatus Jégu & Santos, 1988, is most similar to Urocleidoides triangulus (Suriano, 1981) Rossin & Timi, 2016 based on the shape of the anchors and bars but differs from U. triangulus in the morphology of the projection of the dorsal bar, the number of rings of male copulatory organ, and by the smaller size of members of hook pairs 1 and 5 compared with those of the remaining pairs. Urocleidoides tocantinensis sp. nov. is easily distinguished from all other species of the genus by the morphology of the vagina, which present a vaginal vestibule with a membranous cap. Urocleidoides triangulus is reported from its type host in the Guandu River, state of Rio de Janeiro. The present study increases the number of Urocleidoides species to 37 recognized species that fit all the generic characters.

Helminths assemblage of Trachemys dorbigni (Testudines: Emydidae) in southern Brazil: implications of anthropogenic environments and hosts genders / Assembleia de helmintos de Trachemys dorbigni (Testudines: Emydidae) no sul do Brasil: implicações dos ambientes antrópicos e do gênero sexual dos hospedeiros

The assemblage of helminths of Trachemys dorbigni was analyzed according two environments (rural and urban) and according to hosts gender. Thus, the helminths found were: Spiroxys contortus (Rudolphi, 1819), Falcaustra affinis (Leidy, 1856), Camallanus emydidius Mascarenhas & Müller, 2017, Dioctophyme renale (Goeze, 1782) (larvae), Eustrongylides sp. (larvae) (Nematoda), Telorchis corti (Stunkard, 1915), Telorchis achavali Mañé-Garzón & Holcman-Spector, 1973, Telorchis spp. (Digenea), Polystomoides rohdei Mañé-Garzón & Holcman-Spector,1968 and Neopolystoma sp. (Monogenoidea). Parasitological indices suggests that S. contortus, F. affinis, C. emydidius, T. corti and P. rohdei are species common in helminth assemblage of T. dorbigni in southern Brazil. Infection by Dioctophyme renale is typical of the urban area and suggest relation with eutrophication process and feedback of parasitic cycle in the freshwater urban environment. Parasitological indices of Neopolystoma sp. and T. achavali suggest to be occasional infections; whereas infection by Eustrongylides sp. could be considered accidental. About Telorchiidae, there was no co-occurrence of the species of this group for the examined hosts. In relation to hosts gender, it was observed that infections by S. contortus, F. affinis, C. emydidius and T. corti had higher rates in females, showing a more intimate association with the females of T. dorbigni. The results suggest that human impact on the environment could affect the infrapopulacional dynamics of parasite species influencing the presence and rates of infection of helminths or exacerbating heterogeneities related to hosts gender.(AU)

A assembleia de helmintos de Trachemys dorbigni foi analizada de acordo com dois ambientes (rural e urbano) e de acordo com o gênero sexual dos hospedeiros. Os helmintos encontrados foram: Spiroxys contortus (Rudolphi, 1819), Falcaustra affinis (Leidy, 1856), Camallanus emydidius Mascarenhas & Müller, 2017, Dioctophyme renale (Goeze, 1782) (larva), Eustrongylides sp. (larva) (Nematoda), Telorchis corti (Stunkard, 1915), Telorchis achavali Mañé-Garzón & Holcman-Spector, 1973, Telorchis spp. (Digenea), Polystomoides rohdei Mañé-Garzón & Holcman-Spector,1968 and Neopolystoma sp. (Monogenoidea). Os indices parasitológicos sugerem que S. contortus, F. affinis, C. emydidius, T. corti e P. rohdei são espécies comuns da assembleia de helmintos de T. dorbigni no extremo sul do Brasil. A infecção por Dioctophyme renale é tipica da area urbana e sugere estar relacionada com os processos de eutrofização e a retroalimentação do ciclo parasitário no ambiente aquático urbano. Os indices parasitológicos de Neopolystoma sp. e T. achavali sugerem que a infecção por estes seja occasional; a infecção por Eustrongylides sp. pode ser considerada acidental. Não houve co-ocorrência entre as espécies de Telorchiidae. Em relação ao gênero sexual, observou-se que as infecções por S. contortus, F. affinis, C. emydidius e T. corti apresentaram taxas mais elevadas nas fêmeas, mostrando uma associação mais íntima com as fêmeas de T. dorbigni. Os resultados sugerem que o impacto humano sobre o ambiente pode afetar a dinâmica das infrapopulações dos helmintos parasitos, influenciando a presença e os índices de infecção de helmintos ou exacerbando heterogeneidades relacionadas ao gênero sexual dos hospedeiros.(AU)

Helminth’s assemblage of Trachemys dorbigni (Testudines: Emydidae) in southern Brazil: implications of anthropogenic environments and host’s genders / Assembleia de helmintos de Trachemys dorbigni (Testudines: Emydidae) no sul do Brasil: implicações dos ambientes antrópicos e do gênero sexual dos hospedeiros

The assemblage of helminths of Trachemys dorbigni was analyzed according two environments (rural and urban) and according to host’s gender. Thus, the helminths found were: Spiroxys contortus (Rudolphi, 1819), Falcaustra affinis (Leidy, 1856), Camallanus emydidius Mascarenhas & Müller, 2017, Dioctophyme renale (Goeze, 1782) (larvae), Eustrongylides sp. (larvae) (Nematoda), Telorchis corti (Stunkard, 1915), Telorchis achavali Mañé-Garzón & Holcman-Spector, 1973, Telorchis spp. (Digenea), Polystomoides rohdei Mañé-Garzón & Holcman-Spector,1968 and Neopolystoma sp. (Monogenoidea). Parasitological indices suggests that S. contortus, F. affinis, C. emydidius, T. corti and P. rohdei are species common in helminth assemblage of T. dorbigni in southern Brazil. Infection by Dioctophyme renale is typical of the urban area and suggest relation with eutrophication process and feedback of parasitic cycle in the freshwater urban environment. Parasitological indices of Neopolystoma sp. and T. achavali suggest to be occasional infections; whereas infection by Eustrongylides sp. could be considered accidental. About Telorchiidae, there was no co-occurrence of the species of this group for the examined hosts. In relation to host’s gender, it was observed that infections by S. contortus, F. affinis, C. emydidius and T. corti had higher rates in females, showing a more intimate association with the females of T. dorbigni. The results suggest that human impact on the environment could affect the infrapopulacional dynamics of parasite species influencing the presence and rates of infection of helminths or exacerbating heterogeneities related to host’s gender.

A assembleia de helmintos de Trachemys dorbigni foi analizada de acordo com dois ambientes (rural e urbano) e de acordo com o gênero sexual dos hospedeiros. Os helmintos encontrados foram: Spiroxys contortus (Rudolphi, 1819), Falcaustra affinis (Leidy, 1856), Camallanus emydidius Mascarenhas & Müller, 2017, Dioctophyme renale (Goeze, 1782) (larva), Eustrongylides sp. (larva) (Nematoda), Telorchis corti (Stunkard, 1915), Telorchis achavali Mañé-Garzón & Holcman-Spector, 1973, Telorchis spp. (Digenea), Polystomoides rohdei Mañé-Garzón & Holcman-Spector,1968 and Neopolystoma sp. (Monogenoidea). Os indices parasitológicos sugerem que S. contortus, F. affinis, C. emydidius, T. corti e P. rohdei são espécies comuns da assembleia de helmintos de T. dorbigni no extremo sul do Brasil. A infecção por Dioctophyme renale é tipica da area urbana e sugere estar relacionada com os processos de eutrofização e a retroalimentação do ciclo parasitário no ambiente aquático urbano. Os indices parasitológicos de Neopolystoma sp. e T. achavali sugerem que a infecção por estes seja occasional; a infecção por Eustrongylides sp. pode ser considerada acidental. Não houve co-ocorrência entre as espécies de Telorchiidae. Em relação ao gênero sexual, observou-se que as infecções por S. contortus, F. affinis, C. emydidius e T. corti apresentaram taxas mais elevadas nas fêmeas, mostrando uma associação mais íntima com as fêmeas de T. dorbigni. Os resultados sugerem que o impacto humano sobre o ambiente pode afetar a dinâmica das infrapopulações dos helmintos parasitos, influenciando a presença e os índices de infecção de helmintos ou exacerbando heterogeneidades relacionadas ao gênero sexual dos hospedeiros.

Two new species of monogenoidean parasites (Platyhelminthes: Neodermata) of ornamental fish of Loricariidae (Siluriformes) from the Xingu River, Brazilian Amazon

ABSTRACT Two new monogenoidean species of Unilatus Mizelle & Kritsky, 1967 found in the gills of loricariids in the Lower Xingu-Iriri rivers are described: Unilatus humboldtii sp. nov. from Baryancistrus niveatus (Castelnau, 1855), Panaque armbrusteri Lujan, Hidalgo & Stewart, 2010, Pseudacanthicus sp. (type-host), and Scobinancistrus aureatus Burgess, 1994; and Unilatus luciarappae sp. nov. from P. armbrusteri. Unilatus humboldtii sp. nov. is distinguished from other congeneric species due to its anterior anchor with well-developed superficial root with depressed or truncated distal portion, and inconspicuous or reduced deep root; anterior bar with posteromedial projection; hooks of pair 1 with dilated shaft comprising 2/3 of the hook length; spiraled male copulatory organ with approximately 16-18 counterclockwise loops. Unilatus luciarappae sp. nov. is characterized by having anterior anchor with well-developed superficial root and reduced deep root, slightly curved shaft, elongated, slightly curved, and tapered point; spiraled MCO with approximately 18-19 counterclockwise loops, with median distal bulbous portion and remaining portion tapered and elongated, comprising 1/4 of the body length; and accessory piece comprising approximately 2/3 of the MCO length. More than fifty years after the description of the type species of Unilatus from an artificial environment (U.S. aquaria), this study represents the first formal record and description of Unilatus species from hosts collected in natural habitats in the Xingu River. Considering the impact of the Belo Monte dam on the formerly pristine conditions of the study region and the importance of loricariids for the ornamental fish trade, we recommend monitoring monogenoidean diversity, parasite-host interaction, as well as the dispersion patterns and pathogenicity of these parasites.

Three new species of Urocleidoides (Monogenoidea: Dactylogyridae) parasitizing characiforms (Actinopterygii: Characiformes) in Tocantins River, states of Tocantins and Maranhão, and new record for U. triangulus in Guandu River, state of Rio de Janeiro, Brazil

Three new species of Urocleidoides Mizelle & Price, 1964 are described from the gills of characiform fishes in the Tocantins River and its tributaries. Urocleidoides boulengerellae sp. nov. is described from Boulengerella cuvieri (Spix & Agassiz, 1829) and differs from all its congeners by the dorsal bar with a long posteromedial projection; male copulatory organ with 2-3 counterclockwise rings and a base with a flange; an accessory piece comprising a robust Y-shaped unit and a sheath-like unit; and a highly sclerotized vaginal canal. Urocleidoides paratriangulus sp. nov., described from Psectrogaster amazonica Eigenmann & Eigenmann, 1889, Cyphocharax gouldingi Vari, 1992, Caenotropus labyrinthicus (Kner, 1858) and Mylesinus paucisquamatus Jégu & Santos, 1988, is most similar to Urocleidoides triangulus (Suriano, 1981) Rossin & Timi, 2016 based on the shape of the anchors and bars but differs from U. triangulus in the morphology of the projection of the dorsal bar, the number of rings of male copulatory organ, and by the smaller size of members of hook pairs 1 and 5 compared with those of the remaining pairs. Urocleidoides tocantinensis sp. nov. is easily distinguished from all other species of the genus by the morphology of the vagina, which present a vaginal vestibule with a membranous cap. Urocleidoides triangulus is reported from its type host in the Guandu River, state of Rio de Janeiro. The present study increases the number of Urocleidoides species to 37 recognized species that fit all the generic characters.

Three new species of Urocleidoides (Monogenoidea: Dactylogyridae) parasitizing characiforms (Actinopterygii: Characiformes) in Tocantins River, states of Tocantins and Maranhão, and new record for U. triangulus in Guandu River, state of Rio de Janeiro, Brazil

Three new species of Urocleidoides Mizelle & Price, 1964 are described from the gills of characiform fishes in the Tocantins River and its tributaries. Urocleidoides boulengerellae sp. nov. is described from Boulengerella cuvieri (Spix & Agassiz, 1829) and differs from all its congeners by the dorsal bar with a long posteromedial projection; male copulatory organ with 2-3 counterclockwise rings and a base with a flange; an accessory piece comprising a robust Y-shaped unit and a sheath-like unit; and a highly sclerotized vaginal canal. Urocleidoides paratriangulus sp. nov., described from Psectrogaster amazonica Eigenmann & Eigenmann, 1889, Cyphocharax gouldingi Vari, 1992, Caenotropus labyrinthicus (Kner, 1858) and Mylesinus paucisquamatus Jégu & Santos, 1988, is most similar to Urocleidoides triangulus (Suriano, 1981) Rossin & Timi, 2016 based on the shape of the anchors and bars but differs from U. triangulus in the morphology of the projection of the dorsal bar, the number of rings of male copulatory organ, and by the smaller size of members of hook pairs 1 and 5 compared with those of the remaining pairs. Urocleidoides tocantinensis sp. nov. is easily distinguished from all other species of the genus by the morphology of the vagina, which present a vaginal vestibule with a membranous cap. Urocleidoides triangulus is reported from its type host in the Guandu River, state of Rio de Janeiro. The present study increases the number of Urocleidoides species to 37 recognized species that fit all the generic characters.(AU)

Two new species of monogenoidean parasites (Platyhelminthes: Neodermata) of ornamental fish of Loricariidae (Siluriformes) from the Xingu River, Brazilian Amazon

Two new monogenoidean species of Unilatus Mizelle & Kritsky, 1967 found in the gills of loricariids in the Lower Xingu-Iriri rivers are described: Unilatus humboldtii sp. nov. from Baryancistrus niveatus (Castelnau, 1855), Panaque armbrusteri Lujan, Hidalgo & Stewart, 2010, Pseudacanthicus sp. (type-host), and Scobinancistrus aureatus Burgess, 1994; and Unilatus luciarappae sp. nov. from P. armbrusteri. Unilatus humboldtii sp. nov. is distinguished from other congeneric species due to its anterior anchor with well-developed superficial root with depressed or truncated distal portion, and inconspicuous or reduced deep root; anterior bar with posteromedial projection; hooks of pair 1 with dilated shaft comprising 2/3 of the hook length; spiraled male copulatory organ with approximately 16-18 counterclockwise loops. Unilatus luciarappae sp. nov. is characterized by having anterior anchor with well-developed superficial root and reduced deep root, slightly curved shaft, elongated, slightly curved, and tapered point; spiraled MCO with approximately 18-19 counterclockwise loops, with median distal bulbous portion and remaining portion tapered and elongated, comprising 1/4 of the body length; and accessory piece comprising approximately 2/3 of the MCO length. More than fifty years after the description of the type species of Unilatus from an artificial environment (U.S. aquaria), this study represents the first formal record and description of Unilatus species from hosts collected in natural habitats in the Xingu River. Considering the impact of the Belo Monte dam on the formerly pristine conditions of the study region and the importance of loricariids for the ornamental fish trade, we recommend monitoring monogenoidean diversity, parasite-host interaction, as well as the dispersion patterns and pathogenicity of these parasites.(AU)

Two new species of monogenoidean parasites (Platyhelminthes: Neodermata) of ornamental fish of Loricariidae (Siluriformes) from the Xingu River, Brazilian Amazon

Two new monogenoidean species of Unilatus Mizelle & Kritsky, 1967 found in the gills of loricariids in the Lower Xingu-Iriri rivers are described: Unilatus humboldtii sp. nov. from Baryancistrus niveatus (Castelnau, 1855), Panaque armbrusteri Lujan, Hidalgo & Stewart, 2010, Pseudacanthicus sp. (type-host), and Scobinancistrus aureatus Burgess, 1994; and Unilatus luciarappae sp. nov. from P. armbrusteri. Unilatus humboldtii sp. nov. is distinguished from other congeneric species due to its anterior anchor with well-developed superficial root with depressed or truncated distal portion, and inconspicuous or reduced deep root; anterior bar with posteromedial projection; hooks of pair 1 with dilated shaft comprising 2/3 of the hook length; spiraled male copulatory organ with approximately 16-18 counterclockwise loops. Unilatus luciarappae sp. nov. is characterized by having anterior anchor with well-developed superficial root and reduced deep root, slightly curved shaft, elongated, slightly curved, and tapered point; spiraled MCO with approximately 18-19 counterclockwise loops, with median distal bulbous portion and remaining portion tapered and elongated, comprising 1/4 of the body length; and accessory piece comprising approximately 2/3 of the MCO length. More than fifty years after the description of the type species of Unilatus from an artificial environment (U.S. aquaria), this study represents the first formal record and description of Unilatus species from hosts collected in natural habitats in the Xingu River. Considering the impact of the Belo Monte dam on the formerly pristine conditions of the study region and the importance of loricariids for the ornamental fish trade, we recommend monitoring monogenoidean diversity, parasite-host interaction, as well as the dispersion patterns and pathogenicity of these parasites.(AU)

Monogenoidea parasites of Oreochromis niloticus submitted to ractopamine supplemented diet from cultivated system / [Monogenoidea parasitos de Oreochromis niloticus provenientes de sistema de cultivo submetidos a uma dieta suplementada com ractopamina]

Oreochromis niloticus (Linnaeus) (Perciformes: Cichlidae), commonly named "tilapia", is the second most cultivated species in the world. Among the diseases that affect tilapia are parasitic diseases caused by parasites of the class Monogenoidea. The aim of the present study was to analyze parasitism rates among specimens of O. niloticus in farming systems, after dietary supplementation with ractopamine, a growth promoter that is used for fattening fish. The action of this substance on the quantitative parameters of infestation by Monogenoidea was evaluated. Samples of O. niloticus were obtained from a fish farm in Brasília, Federal District, Brazil. Their gills were removed and fixed. Four species of monogenoideans were collected: Cichlidogyrus halli, C. sclerosus, C. thurstonae and Scutogyrus longicornis. The results from this study indicate that the monogenoidean parasites of tilapias examined here presented different behaviors in relation to the ractopamine concentrations that were added to the food. The parasitological indexes did not present significant reductions through using ractopamine, thus leading to the conclusion that administration of ractopamine is not efficient as a method for controlling infestations of monogenoidean parasites.(AU)

Oreochromis niloticus (Linnaeus) (Perciformes: Cichlidae), tilápia, é a segunda espécie mais cultivada no mundo. Entre outras doenças que afetam a tilápia, estão as doenças provocadas por parasitos da classe Monogenoidea. O presente estudo teve como objetivo analisar os índices de parasitismo em espécies de O. niloticus provenientes de sistemas de cultivo, submetidos a uma dieta com suplementação de ractopamina, usada como promotor de crescimento no estágio de engorda dos peixes, para avaliar as ações dessa substância nos parâmetros quantitativos da infestação por Monogenoidea. Exemplares de O. niloticus obtidos na piscicultura "Agropecuária do Buriti Perdido", em Brasília, Distrito Federal, Brasil, foram examinados; as brânquias foram removidas e fixadas. Quatro espécies foram coletadas: Cichlidogyrus halli, C. sclerosus, C. thurstonae e Scutogyrus longicornis. Os resultados obtidos no presente estudo indicaram que as espécies de Monogenoidea parasitos de tilápia examinadas apresentam diferentes comportamentos relacionados à concentração de ractopamina adicionada ao alimento. Os índices parasitológicos não apresentaram redução significativa pelo uso da ractopamina, levando à conclusão de que a ractopamina não é eficiente como método de controle parasitário em infestações por Monogenoidea.(AU)

New records of helminths in Chelidae freshwater turtles (Testudines) in South America / Novos registros de helmintos em tartarugas de água doce Chelidae (Testudines) na América do Sul

. Estudos helmintológicos com tartarugas de água doce Chelidae na América do Sul foram conduzidos na Argentina, Uruguai e Brasil, onde foram relatados nematoides, digenéticos e monogenéticos. Nesse contexto, o objetivo do estudo é registrar novas ocorrências de helmintos gastrintestinais associados a Acanthochelys spixii, Hydromedusa tectifera e Phrynops hilarii. Foram examinados 65 hospedeiros, provenientes da região sul do Rio Grande do Sul, Brasil. Sete taxa pertencentes a Nematoda, Digenea e Monogenoidea são reportados em novos hospedeiros na América do Sul bem como, um Nematoda e dois Digenea tem novo registro de hospedeiro para o Brasil. Assim, o estudo amplia o conhecimento sobre a diversidade de helmintos e a distribuição geográfica dos taxa encontrados parasitando tartarugas Chelidae.

Helminthological studies with Chelidae freshwater turtles in South America were conducted in Argentina, Uruguay and Brazil, where nematodes, digeneans and monogeneans were reported. In this context, the study aims to report new cases of gastrointestinal helminth parasites of Acanthochelys spixii, Hydromedusa tectifera, and Phrynops hilarii. A total of 65 hosts from the southern region of Rio Grande do Sul, Brazil, were examined. Seven taxa belonging to Nematoda, Digenea, and Monogenoidea have new cases on hosts Chelidae in South America, as well as a Nematoda and two Digenea have new host cases for Brazil. Thus, the study expands the knowledge about the diversity of helminths and the geographic distribution of taxa associated with Chelidae turtles.

New records of helminths in Chelidae freshwater turtles (Testudines) in South America / Novos registros de helmintos em tartarugas de água doce Chelidae (Testudines) na América do Sul

. Estudos helmintológicos com tartarugas de água doce Chelidae na América do Sul foram conduzidos na Argentina, Uruguai e Brasil, onde foram relatados nematoides, digenéticos e monogenéticos. Nesse contexto, o objetivo do estudo é registrar novas ocorrências de helmintos gastrintestinais associados a Acanthochelys spixii, Hydromedusa tectifera e Phrynops hilarii. Foram examinados 65 hospedeiros, provenientes da região sul do Rio Grande do Sul, Brasil. Sete taxa pertencentes a Nematoda, Digenea e Monogenoidea são reportados em novos hospedeiros na América do Sul bem como, um Nematoda e dois Digenea tem novo registro de hospedeiro para o Brasil. Assim, o estudo amplia o conhecimento sobre a diversidade de helmintos e a distribuição geográfica dos taxa encontrados parasitando tartarugas Chelidae.(AU)

Helminthological studies with Chelidae freshwater turtles in South America were conducted in Argentina, Uruguay and Brazil, where nematodes, digeneans and monogeneans were reported. In this context, the study aims to report new cases of gastrointestinal helminth parasites of Acanthochelys spixii, Hydromedusa tectifera, and Phrynops hilarii. A total of 65 hosts from the southern region of Rio Grande do Sul, Brazil, were examined. Seven taxa belonging to Nematoda, Digenea, and Monogenoidea have new cases on hosts Chelidae in South America, as well as a Nematoda and two Digenea have new host cases for Brazil. Thus, the study expands the knowledge about the diversity of helminths and the geographic distribution of taxa associated with Chelidae turtles.(AU)

Parasitological assessment in hybrids Serrasalmidae fish farmed in Brazil / Avaliação parasitológica em híbridos de peixes Serrasalmidae cultivados no Brasil

This study evaluated the parasitic fauna of hybrids tambacu (Colossoma macropomum × Piaractus mesopotamicus) and patinga (P. mesopotamicus × Piaractus brachypomus) and their host-parasite-environment interaction during the warm and cold seasons in two fish farms located in the State of Mato Grosso do Sul, Brazil, South America. A total of 120 fish, being 60 fish for species (30 in the warm season and 30 in the cold season) were examined. Water quality was measured weekly to evaluate the interaction between environmental conditions and parasitism. Fifteen species of parasites were found: Ichthyophthirius multifiliis, Chilodonella hexasticha e Trichodina sp. (Protozoa), Henneguya piaractus, Myxobolus colossomatis and Myxobolus cuneus (Myxozoa); Anacanthorus penilabiatus, Mymarothecium boegeri, Mymarothecium viatorum, and Notozothecium janauachensis (Monogenoidea), Goezia spinulosa and Goezia sp. (Nematoda), Echinorhynchus jucundus (Acanthocephala), and Dolops carvalhoi, Lernaea cyprinacea (Crustacea). The ciliate protozoan I. multifiliis and monogenoids were the most prevalent parasites in the cold and warm seasons for both hybrids in the different culture systems intensive production and sportive fishing. It was observed that the serrasalmid hybrids are more susceptible to parasites and harbor high diversity of parasites in relation to the parental species C. macropomum, P. mesopotamicus and P. brachypomus, with a predominance of ectoparasites.(AU)

Este estudo avaliou a fauna parasitária de híbridos tambacu (Colossoma macropomum × Piaractus mesopotamicus) e patinga (P. mesopotamicus × Piaractus brachypomus) e a interação hospedeiro-parasito-ambiente durante as estações quente e fria em duas pisciculturas localizadas no estado de Mato Grosso do Sul, Brasil, América do Sul. Foram examinados um total de 120 peixes, sendo 60 peixes por espécie. A qualidade da água foi mensurada semanalmente para avaliar a interação entre condições ambientais e parasitismo. Foram encontradas quinze espécies de parasitos: Ichthyophthirius multifiliis, Chilodonella hexasticha e Trichodina sp. (Protozoa); Henneguya piaractus, Myxobolus colossomatis e Myxobolus cuneus (Myxozoa), Anacanthorus penilabiatus, Mymarothecium boegeri, Mymarothecium viatorum e Notozothecium janauachensis (Monogenoidea), Goezia spinulosa e Goezia sp. (Nematoda), Echinorhynchus jucundus (Acanthocephala), Dolops carvalhoi eLernaea cyprinacea (Crustacea). O protozoário ciliado I. multifiliis e helmintos monogenoides foram os parasitos mais prevalentes nas estações fria e quente para ambos os híbridos nos diferentes sistemas de cultivo, produção intensiva comercial e pesca esportiva. Observou-se que os híbridos de serrasalmídeos são mais suscetíveis aos parasitos e abrigam alta diversidade parasitária em relação às espécies parentais, C. macropomum, P. mesopotamicus e P. brachypomus em ambiente de cultivo com predominância de ectoparasitos.(AU)

New species of Urocleidoides (Monogenoidea: Dactylogyridae) from the gills of two species of Anostomidae from the Brazilian Amazon / Novas espécies de Urocleidoides (Dactylogyridae) das brânquias de duas espécies de Anostomidae da Amazônia brasileira

Three species (2 new) of Urocleidoides are described and/or reported from the gills of Schizodon fasciatus and Laemolyta proxima (Anostomidae) from the Jari River in the eastern Brazilian Amazon. Urocleidoides jariensis n. sp. presents a sclerotized, tubular, spiral male copulatory organ (MCO) with one counterclockwise coil, a circular sclerotized tandem brim associated with the base of the MCO; a heavily sclerotized, funnel-shaped vaginal vestibule; and a broadly V-shaped ventral bar with anteromedial constriction and enlarged ends. Urocleidoides ramentacuminatus n. sp. has a sclerotized, tubular, spiral MCO with one counterclockwise coil; an accessory piece with a hook-shaped distal portion; and a dorsal anchor with a short, straight shaft; anchor point with ornamentation as sclerotized shredded filaments. Urocleidoides paradoxus is reported for the first time parasitizing S. fasciatus.(AU)

Três espécies (2 novas) de Urocleidoides são descritas e/ou reportadas das brânquias de Schizodon fasciatus e Laemolyta proxima (Anostomidae) da bacia do Rio Jari, na Amazônia oriental brasileira. Urocleidoides jariensis n. sp. apresenta um órgão copulatório masculino (OCM) convoluto, com uma volta no sentido anti-horário, uma borda em tandem esclerotizada circular, associada à base do OCM; um vestíbulo vaginal fortemente esclerotizado e em forma de funil; um canal vaginal esclerotizado na porção proximal; e uma barra ventral em forma de V com constrição anteromedial e ampliações terminais. Urocleidoides ramentacuminatus n. sp. tem um OCM convoluto com, aproximadamente, uma volta no sentido anti-horário; uma peça acessória com uma porção distal em forma de gancho; uma âncora dorsal com haste curta e reta; e ponta da âncora com ornamentação como filamentos desfiados esclerotizados. Urocleidoides paradoxus é relatada pela primeira vez parasitando S. fasciatus.(AU)

Neotropical Monogenoidea 62. Biotodomella mirospinata gen. nov., sp. nov. (Polyonchoinea: Dactylogyridae): a parasite of the gills of Biotodoma cupido (Cichliformes: Cichlidae), from the Peruvian Amazon

Biotodomella gen. nov. (Monogenoidea: Dactylogyridae) is proposed to accommodate Biotodomella mirospinata sp. nov., found on the gills of Biotodoma cupido (Heckel, 1840) (“cara bonita” or “green-streaked eartheater”), a freshwater cichlid from the Peruvian Amazon. The new genus and species differ from other Neotropical dactylogyrids in having the hooks of each hook pair well-differentiated from the remaining pairs, shafts varying in robustness, weakly sclerotized expansions at the proximal end of shaft, and a dorsal anchor with grooved shaft, bifid point. This study represents the first record of a monogenoid from a species of Biotodoma Eigenmann & Kennedy, 1903.

Neotropical Monogenoidea 62. Biotodomella mirospinata gen. nov., sp. nov. (Polyonchoinea: Dactylogyridae): a parasite of the gills of Biotodoma cupido (Cichliformes: Cichlidae), from the Peruvian Amazon

Biotodomella gen. nov. (Monogenoidea: Dactylogyridae) is proposed to accommodate Biotodomella mirospinata sp. nov., found on the gills of Biotodoma cupido (Heckel, 1840) (“cara bonita” or “green-streaked eartheater”), a freshwater cichlid from the Peruvian Amazon. The new genus and species differ from other Neotropical dactylogyrids in having the hooks of each hook pair well-differentiated from the remaining pairs, shafts varying in robustness, weakly sclerotized expansions at the proximal end of shaft, and a dorsal anchor with grooved shaft, bifid point. This study represents the first record of a monogenoid from a species of Biotodoma Eigenmann & Kennedy, 1903.(AU)

Dactylogyrids (Platyhelminthes: Monogenoidea) from the gills of Hassar gabiru and Hassar orestis (Siluriformes: Doradidae) from the Xingu Basin, Brazil

Four species of Cosmetocleithrum (three new) and one new species of Vancleaveus are described or reported parasitizing the gills of doradid catfishes (Siluriformes) from Xingu River and related tributaries: Cosmetocleithrum phryctophallus sp. nov. and Cosmetocleithrum bifurcum Mendoza-Franco, Mendoza-Palmero & Scholz, 2016 from Hassar orestis; Cosmetocleithrum leandroi sp. nov. from Hassar gabiru; Cosmetocleithrum akuanduba sp. nov. and Vancleaveus klasseni sp. nov. from Hassar orestis and H. gabiru. Cosmetocleithrum phryctophallus sp. nov. differs from its congeners by possessing a male copulatory organ (MCO) with 2 ½ counterclockwise rings, and an accessory piece with an elongate torch-shaped blade. Cosmetocleithrum leandroi sp. nov. has a MCO comprising a coil of about 3 ½ rings, a sigmoid accessory piece with a cup-shaped distal portion, a single type of hooks, and anchors with poorly differentiated roots. Cosmetocleithrum akuanduba sp. nov. is characterized mainly by having a J-shaped MCO, an elongate accessory piece with sharp distal region, distal portion with a small gutter, and a heavily sclerotized vagina with short “S”-shaped vaginal canal. Vancleaveus klasseni sp. nov. differs from the other species of the genus occurring in doradids by possessing anchors with triangular to subtriangular superficial root, developed deep root, and a coiled MCO with 2 ½ counterclockwise rings. Cosmetocleithrum bifurcum was reported for the first time parasitizing doradids from Brazilian Amazon.(AU)

Dactylogyrids (Platyhelminthes: Monogenoidea) from the gills of Hassar gabiru and Hassar orestis (Siluriformes: Doradidae) from the Xingu Basin, Brazil

Four species of Cosmetocleithrum (three new) and one new species of Vancleaveus are described or reported parasitizing the gills of doradid catfishes (Siluriformes) from Xingu River and related tributaries: Cosmetocleithrum phryctophallus sp. nov. and Cosmetocleithrum bifurcum Mendoza-Franco, Mendoza-Palmero & Scholz, 2016 from Hassar orestis; Cosmetocleithrum leandroi sp. nov. from Hassar gabiru; Cosmetocleithrum akuanduba sp. nov. and Vancleaveus klasseni sp. nov. from Hassar orestis and H. gabiru. Cosmetocleithrum phryctophallus sp. nov. differs from its congeners by possessing a male copulatory organ (MCO) with 2 ½ counterclockwise rings, and an accessory piece with an elongate torch-shaped blade. Cosmetocleithrum leandroi sp. nov. has a MCO comprising a coil of about 3 ½ rings, a sigmoid accessory piece with a cup-shaped distal portion, a single type of hooks, and anchors with poorly differentiated roots. Cosmetocleithrum akuanduba sp. nov. is characterized mainly by having a J-shaped MCO, an elongate accessory piece with sharp distal region, distal portion with a small gutter, and a heavily sclerotized vagina with short “S”-shaped vaginal canal. Vancleaveus klasseni sp. nov. differs from the other species of the genus occurring in doradids by possessing anchors with triangular to subtriangular superficial root, developed deep root, and a coiled MCO with 2 ½ counterclockwise rings. Cosmetocleithrum bifurcum was reported for the first time parasitizing doradids from Brazilian Amazon.