Ozolaimus megatyphlon and Ozolaimus cirratus parasitizing the Iguana iguana (Linnaeus, 1758) from Marajó Island, Pará, Brasil: new occurrence and morphological redescription.

This study aimed to redescribe two species of Ozolaimus, parasites of free-living green iguanas native to Marajó Island. The gastrointestinal system of four iguana specimens was evaluated for the presence of helminths. Altogether, 12,028 nematodes were found, with a prevalence of 100%, an infection range of 780 to 7,736 nematodes, an infection intensity of 3.007, and a mean abundance of 3,007. Light microscopy and scanning electron microscopy were used to determine the species of nematodes found. The cecum was the site of infection that had the highest parasitic load. Morphologically, the nematodes were compatible with the genus Ozolaimus Dujardin, 1844, with the species Ozolaimus megatyphlon (Rudolphi, 1819) Dujardin, 1845, and Ozolaimus cirratus Linstow, 1906. Scanning electron microscopy showed the presence of small structures (serrated in Ozolaimus cirratus and rounded in Ozolaimus megatyphlon) located below the esophageal leaves. We also evidenced the phasmids in both species; this is the first record of these structures in nematodes of the genus Ozolaimus. In addition, this work expands the records on the geographic distribution of these parasites.

A new nematode of the family Capillariidae identified in Cairina moschata (Linnaeus) on Marajó Island in the Brazilian Amazon.

Capillaria Zeder, 1800, parasitizes the organs and tissues of several hosts, including the domestic duck Cairina moschata (Linnaeus). This article describes a new species of Capillaria in domestic ducks identified based on morphological studies and molecular analyses of the ribosomal RNA gene. Thirty-eight specimens of C. moschata from the municipality of Soure, Marajó Island, Pará, Brazil. The organs of the birds' digestive tract were analyzed under a stereomicroscope to confirm the parasitic infection, after which the collected nematodes were identified by light microscopy, scanning electron microscopy, and molecular analysis. Capillariids parasitized the intestine and cecum of the examined birds. These parasites had three bacillary bands and a pair of elongated precloacal papillae on the tail. Phylogenetic analysis indicated that the new species formed a sister clade with Capillaria spinulosa (Linstow, 1890), as described in Indonesia and Japan. Based on morphological distinctions and molecular data, Capillaria cairina n. sp. can be considered a new parasite species of C. moschata in the Brazilian Amazon.

Redescription of Brevimulticaecum baylisi () (Nematoda: Heterocheilidae), a parasite of Caiman crocodilus (Crocodylia: Alligatoridae) in the north-eastern Peruvian Amazon.

Caiman crocodilus is among the most abundant and widely distributed predators in the Neotropical region. These animals consume prey such as crustaceans, birds, small mammals, reptiles, amphibians, and fish, which can carry infective larval forms of nematodes. Brevimulticaecum has few studies on its morphology available, lacking detailed images. Therefore, the aim of this study was to redescribe Brevimulticaecum baylisi, stomach parasite of Caiman crocodilus, from subsistence hunting in the Yavari-Mirin River, Peruvian Amazon, using light and scanning electron microscopy. Four caimans were analyzed, and, macroscopically, all had ulcerative lesions in the stomach caused by this parasite. Histopathology showed an inflammatory infiltrate with a predominance of lymphocytes. Morphological characteristics of nematodes include the presence of three diamond-shaped lips wider than they are long, interlabia pyramidal, excretory pore located above the nerve ring, present intestinal cecum, ventriculus with five ventricular appendages, and long, winged spicules. These morphological characters, added to the number and distribution of the pre- and postcloacal papillae of the male specimens, allowed the identification of these parasites as B. baylisi. Scanning electron microscopy of these nematodes showed the presence of a dentigerous ridge on the inner surface of the lips in both sexes, while in males, the presence of a horseshoe-shaped median papilla was observed on the upper lip of the cloaca. Our research, therefore, adds these characteristics to the original description of B. baylisi, in addition to expanding the biogeographical distribution of this parasite.

Systematic and parasite-host relationship by Baruscapillaria appendiculata in Phalacrocorax brasilianus collected from Marajó Island, State of Pará, Brazil.

The genus Baruscapillaria Moravec, 1982 has six valid species recorded in birds Phalacrocoracidae, namely Baruscapillaria appendiculata Freitas, 1933, B. spiculata Freitas, 1933, B. carbonis (Dubinin & Dubinina, 1940), B. jaenschi (Johnston & Mawson, 1945), B. phalacrocoraxi (Borgarenko, 1975) and B. rudolphii Moravec, Scholz and Nasincová, 1994. Helminthological tests carried out on cormorants of the species Phalacrocorax brasilianus (Gmelin), a migratory bird that occurs in the northeast of the State of Pará, Brazil, demonstrate B. appendiculata parasitizing the cloaca of these birds, through light microscopy, scanning electron microscopy and molecular biology. These studies allowed a redescription of males and females of this nematode in these hosts and in this geographical area through integrative taxonomy. The occurrence of lesions in the cloaca caused by this nematode parasite was registered using histological analysis. This is a new geographic report for this nematode.

Morphological and molecular characterization of Contracaecum australe (Nematoda: Anisakidae) parasitizing Phalacrocorax brasilianus (Aves: Phalacrocoracidae) on the north coast of Brazil.

For the first time in Brazil, Contracaecum australe is recorded parasitizing Phalacrocorax brasilianus (Aves, Suliformes, Phalacrocoracidae) from the Marine Extractive Reserve of Soure on Marajó Island, Brazilian Amazon. Its morphology revealed a body with a transversally striated cuticle, smooth or slightly cleft interlabia, lips with auricles, labial papillae, and conspicuous amphids. In males, the presence of the median papilla on the upper lip of the cloaca and spicules that reach almost half of the body of the parasite. These morphological characters, added to the number and distribution of the pre- and postcloacal papillae of the male specimens, and supported by the molecular phylogeny from the analysis of the ITS-1, 5.8S and ITS-2 genes, allowed the identification of these parasites.

A new species of Huffmanela (Nematoda: Trichosomoididae) parasitizing Colomesus psittacus (Tetraodontiformes) from Marajó Island, Pará State, Brazil.

The puffer fish Colomesus psittacus, is not commercialized on Marajó Island. They are captured as bycacth and discarded dead in the environment in artisanal fisheries that occur in the estuaries of northern Brazil. In this sense, the objective was to identify the parasites present in the gills and to evaluate the histopathological alterations caused by these nematodes of the genus Huffmanela. Fifty-five fish were analyzed, and thirty-five specimens showed the parasite in the gills. Morphological characteristics suggest that it is a new species of the genus Huffmanela, and the histopathological exams showed an edematous inflammation in the secondary lamella and the presence of eggs of this nematode, which is the first record of this parasite in C. psittacus in Brazil.

A new species of Huffmanela (Nematoda: Trichosomoididae) parasitizing Colomesus psittacus (Tetraodontiformes) from Marajó Island, Pará State, Brazil / Uma nova espécie de Huffmanela (Nematoda: Trichosomoididae) parasitando Colomesus psittacus (Tetraodontiformes) da Ilha de Marajó, Pará, Brasil

Abstract The puffer fish Colomesus psittacus, is not commercialized on Marajó Island. They are captured as bycacth and discarded dead in the environment in artisanal fisheries that occur in the estuaries of northern Brazil. In this sense, the objective was to identify the parasites present in the gills and to evaluate the histopathological alterations caused by these nematodes of the genus Huffmanela. Fifty-five fish were analyzed, and thirty-five specimens showed the parasite in the gills. Morphological characteristics suggest that it is a new species of the genus Huffmanela, and the histopathological exams showed an edematous inflammation in the secondary lamella and the presence of eggs of this nematode, which is the first record of this parasite in C. psittacus in Brazil.

Resumo O baiacu amazônico Colomesus psittacus é um peixe de importância comercial para a aquariofilia, além de ser capturado como bycacth e descartado morto no ambiente nas pescarias artesanais que ocorrem nos estuários da região Norte do Brasil. Nesse sentido, objetivou-se identificar e descrever nematódeos do gênero Huffmanela em baiacus oriundos da ilha de Marajó, bem como as alterações histopatológicas causadas por eles. Cinquenta e cinco peixes foram analisados, e trinta e cinco espécimes apresentaram o parasita nas branquias. Características morfológicas sugerem tratar-se de uma nova espécie do gênero Huffmanela, e os exames histopatológicos demonstraram uma inflamação edematosa na lamela secundária e presença de ovos desse nematódeo. Esse fato se torna o primeiro registro desse gênero parasito em C. psittacus no Brasil.

Diversity of endohelminths parasitizing bred Muscovy ducks Cairina moschata domestica (Anseriformes: Anatidae) from the eastern Brazilian Amazon.

Raising of Muscovy ducks Cairina moschata domestica for subsistence of human populations is common in northern Brazil, although their helminth infections have been poorly investigated, despite the possible presence of helminths with zoonotic potential. The aim of this study was to investigate the diversity of parasite endohelminths in C. moschata domestica raised in the Marajó Island region, state of Pará, Brazilian Amazon region. Of 33 specimens examined, 90.9% were parasitized by one or more parasite species, for a total of 926 parasites recorded. The species mean richness of endohelminths varied from 0 to 6, and there was a predominance of hosts with 1 to 2 species of parasite endohelminths and low prevalence and low abundance of parasites. This was the first report of larvae of Anisakis sp., Contracaecum sp., Hysterotylacium sp., Raphidascaris sp., Eustrongylides sp., Syngamus sp., Ascocotyle sp. and Athesmia heterolecithodes for C. moschata domestica. The parasitic community of C. moschata domestica was composed of 11 species, with a high species richness for nematode species and a small number of digeneans.

First report of Anisakis sp. (Nematoda: Anisakidae) parasitizing Muscovy duck in Marajó Island, state of Pará, Brazil.

Among the avian used for human consumption, the Muscovy duck is well adapted to various climatic conditions and its breeding is widespread due to its easy handling, and its meat is widely consumed and appreciated, especially in the cuisine of northern Brazil. The present study aimed to report and identify taxonomically the nematodes found in the esophagus of Muscovy ducks reared and marketed in the municipality of Soure, Marajó Island, state of Pará, Brazil, and discuss its zoonotic potential to human. The samples consisted of 30 specimens of Cairina moschata domestica analyzed. A total of 258 nematodes were recovered, which were strongly fixed in the esophageal mucosa of hosts. The morphological and morphometric characteristics were compatible with Anisakis third-stage larvae.

Eucoleus contortus (Nematoda: Capillariidae), a parasite of Cairina moschata domestica (Anseriformes: Anatidae) on Marajó Island, Pará State, in Brazilian Amazon.

The family Capillariidae is one of the most important in the superfamily Trichinelloidea, with 27 genera and more than 300 species parasitizing vertebrates. This study considers the morphology, morphometry and prevalence of Eucoleus contortus parasitizing the Muscovy duck Cairina moschata domestica esophagus from Marajó Island, in State of Pará, Brazil. Morphologically the nematodes had a filiform body, with transversely striated cuticle, long esophagus, divided into two parts, one muscular and another consisting of stichocytes, spicule weakly sclerotized, spiny sheath and pseudobursa present in males. Females had a pre-equatorial vulva, barrel-shaped eggs and were bioperculated. In the northern region of Brazil, the Muscovy duck is an abundant bird, and one of the items in the food supply for human communities. The occurrence of E. contortus adds data to the biodiversity of parasites described in Anseriform birds of the Brazilian Amazon, especially those used as source of protein by human communities of Marajó.

Eucoleus contortus (Nematoda: Capillariidae), a parasite of Cairina moschata domestica (Anseriformes: Anatidae) on Marajó Island, Pará State, in Brazilian Amazon / Eucoleus contortus (Nematoda: Capillariidae), um parasito de Cairina moschata domestica (Anseriformes: Anatidae) na Ilha de Marajó, Estado do Pará, na Amazônia Brasileira

Abstract The family Capillariidae is one of the most important in the superfamily Trichinelloidea, with 27 genera and more than 300 species parasitizing vertebrates. This study considers the morphology, morphometry and prevalence of Eucoleus contortus parasitizing the Muscovy duck Cairina moschata domestica esophagus from Marajó Island, in State of Pará, Brazil. Morphologically the nematodes had a filiform body, with transversely striated cuticle, long esophagus, divided into two parts, one muscular and another consisting of stichocytes, spicule weakly sclerotized, spiny sheath and pseudobursa present in males. Females had a pre-equatorial vulva, barrel-shaped eggs and were bioperculated. In the northern region of Brazil, the Muscovy duck is an abundant bird, and one of the items in the food supply for human communities. The occurrence of E. contortus adds data to the biodiversity of parasites described in Anseriform birds of the Brazilian Amazon, especially those used as source of protein by human communities of Marajó.

Resumo A família Capillariidae é uma das mais importantes da superfamília Trichinelloidea, com 27 gêneros e mais de 300 espécies parasitando os vertebrados. Este estudo considera a morfologia, morfometria e prevalência de Eucoleus contortus parasito do esôfago de pato doméstico na Ilha de Marajó, Estado do Pará, Brasil. Morfologicamente os nematódeos apresentaram corpo filiforme, com cutícula estriada transversalmente, esôfago longo, dividido em duas partes, sendo uma muscular e outra formado por esticócitos, espículo fracamente esclerotizado, bainha espinhosa e pseudobursa presente nos machos. Fêmeas com vulva pré-equatorial, ovos em forma de barril e bioperculado. Na região norte do Brasil, o pato doméstico é uma ave abundante, compondo um dos itens do suprimento de alimentos para muitas pessoas. A ocorrência de E. contortus adiciona dados à biodiversidade de parasitos descritos em aves Anseriformes da Amazônia brasileira, em especial as utilizadas como fonte de proteína por comunidades humanas do Marajó.

Cucullanus marajoara n. sp. (Nematoda: Cucullanidae), a parasite of Colomesus psittacus (Osteichthyes: Tetraodontiformes) in the Marajó, Brazil / Cucullanus marajoara n. sp. (Nematoda: Cucullanidae), um parasito de Colomesus psittacus (Osteichthyes: Tetraodontiformes) no Marajó, Brasil

Abstract Cucullanus marajoara n. sp. (Cucullanidae) is reported to parasitize Colomesus psittacus (Tetraodontiformes), which is a fish species from the Marajó Archipelago, state of Pará, estuarine region of the Brazilian Amazon. The new species differs from similar species by the presence of a protruding upper lip on the cloacal opening, the distribution of the cloacal papillae: five pre-cloacal papillae pairs and 5 are ventral and located posteriorly to the pre-cloacal sucker and an unpaired papilla is located on the upper cloacal lip and five post-cloacal pairs, and a pair of lateral phasmids located between papillae pairs. Additionally, Cucullanus marajoara n. sp. is compared to other species of this genus described in Brazil, particularly Cucullanus ageneiosus and Cucullanus oswaldocruzi, which both occur in the same zoogeographic region of this study but parasitize fish of a different order (Siluriformes). Cucullanus dodsworthi and Cucullanus brevicaudatus are the only described species parasitizing fish of the order Tetradontiformes in Brazil, and the new species differs from these species by the distribution of the cloacal papillae and the host habitat. The description of Cucullanus marajoara n. sp. adds data to the biodiversity of described parasites that parasitize Tetradontiformes of the estuarine ichthyofauna in the Brazilian Amazon.

Resumo Cucullanus marajoara n. sp. (Cucullanidae) é descrita parasitando Colomesus psittacus (Tetraodontiformes) peixe do arquipélago de Marajó, Estado do Pará, região estuarina da Amazônia brasileira. A nova espécie difere de seus congêneres por apresentar lábio superior da abertura cloacal protrudente e na distribuição de papilas cloacais: 5 pares pré-cloacais, e uma papila não pareada no lábio superior da cloaca e 5 pares pós-cloacais, um par de fasmídeos laterais. Além disso, Cucullanus marajoara n. sp. é comparada com outras espécies do gênero descritas no Brasil, em especial Cucullanus ageneiosus e Cucullanus oswaldocruzi, ambos parasitos de peixes da ordem Siluriformes; porém, ocorrendo na mesma região zoogeográfica deste estudo, diferem da ordem do hospedeiro da nova espécie (Tetraodontiformes). Cucullanus dodsworthi e Cucullanus brevicaudatus são as únicas espécies descritas parasitando peixe da ordem Tetradontiformes no Brasil, e a nova espécie difere dessas na distribuição das papilas cloacais e habitat dos hospedeiros. Cucullanus marajoara n. sp. adiciona dados a biodiversidade de parasitos descritos parasitando Tetradontiformes da ictiofauna estuarina da Amazônia brasileira.

Cucullanus marajoara n. sp. (Nematoda: Cucullanidae), a parasite of Colomesus psittacus (Osteichthyes: Tetraodontiformes) in the Marajó, Brazil.

Cucullanus marajoara n. sp. (Cucullanidae) is reported to parasitize Colomesus psittacus (Tetraodontiformes), which is a fish species from the Marajó Archipelago, state of Pará, estuarine region of the Brazilian Amazon. The new species differs from similar species by the presence of a protruding upper lip on the cloacal opening, the distribution of the cloacal papillae: five pre-cloacal papillae pairs and 5 are ventral and located posteriorly to the pre-cloacal sucker and an unpaired papilla is located on the upper cloacal lip and five post-cloacal pairs, and a pair of lateral phasmids located between papillae pairs. Additionally, Cucullanus marajoara n. sp. is compared to other species of this genus described in Brazil, particularly Cucullanus ageneiosus and Cucullanus oswaldocruzi, which both occur in the same zoogeographic region of this study but parasitize fish of a different order (Siluriformes). Cucullanus dodsworthi and Cucullanus brevicaudatus are the only described species parasitizing fish of the order Tetradontiformes in Brazil, and the new species differs from these species by the distribution of the cloacal papillae and the host habitat. The description of Cucullanus marajoara n. sp. adds data to the biodiversity of described parasites that parasitize Tetradontiformes of the estuarine ichthyofauna in the Brazilian Amazon.

Gnathostomatidae nematode parasite of Colomesus psittacus (Osteichthyes, Tetraodontiformes) in the Ilha de Marajó, Brazilian Amazon.

The genus Gnathostoma comprises 17 species, whose adult specimens are found in the stomach serosa of animals that consume raw fish; some species of the genus are zoonotic agents. The present study describes the presence of a nematode (Gnathostomatidae) parasitizing the digestive tract of Colomesus psittacus in the Ilha de Marajó in the eastern Brazilian Amazon. Thirty specimens of C. psittacus were collected in the municipality of Soure, Ilha de Marajó, state of Pará, Brazil, transported to the laboratory, necropsied and the helminths were collected and fixed. Of the 30 fish that were studied, 16.67% were parasitized with nematodes. The nematode larvae found encysted in the intestinal serosa have anterior region with two lips, each with a pair of papillae; a cephalic bulb armed with six rows of discontinuous spines; four cervical sacs; a claviform esophagus; cuticular striations along the body; a simple excretory pore; and a short tail ending in a mucron. These morphological structures are diagnostic characters of the genus Gnathostoma, whose adults parasitize the stomach of carnivorous mammals and, rarely, the stomach of fish. However, fish, amphibians, reptiles, and birds are intermediate hosts of the third-stage larvae (L3), and humans may act as accidental hosts.

Gnathostomatidae nematode parasite of Colomesus psittacus (Osteichthyes, Tetraodontiformes) in the Ilha de Marajó, Brazilian Amazon / Nematoide Gnathostomatidae parasito de Colomesus psittacus (Osteichthyes, Tetraodontiformes) na Ilha de Marajó, Amazônia Brasileira

Abstract The genus Gnathostoma comprises 17 species, whose adult specimens are found in the stomach serosa of animals that consume raw fish; some species of the genus are zoonotic agents. The present study describes the presence of a nematode (Gnathostomatidae) parasitizing the digestive tract of Colomesus psittacus in the Ilha de Marajó in the eastern Brazilian Amazon. Thirty specimens of C. psittacus were collected in the municipality of Soure, Ilha de Marajó, state of Pará, Brazil, transported to the laboratory, necropsied and the helminths were collected and fixed. Of the 30 fish that were studied, 16.67% were parasitized with nematodes. The nematode larvae found encysted in the intestinal serosa have anterior region with two lips, each with a pair of papillae; a cephalic bulb armed with six rows of discontinuous spines; four cervical sacs; a claviform esophagus; cuticular striations along the body; a simple excretory pore; and a short tail ending in a mucron. These morphological structures are diagnostic characters of the genus Gnathostoma, whose adults parasitize the stomach of carnivorous mammals and, rarely, the stomach of fish. However, fish, amphibians, reptiles, and birds are intermediate hosts of the third-stage larvae (L3), and humans may act as accidental hosts.

Resumo O gênero Gnasthostoma é composto por 17 espécies, sendo reportado o caráter zoonótico para algumas. Este trabalho descreve a presença de nematoide da família Gnathostomatidae, parasito do trato digestório de Colomesus psittacus, na Ilha de Marajó, Amazônia oriental brasileira, transportados para o laboratório, necropsiados os helmintos colhidos e fixados. Dos 30 animais analisadas 16,67% estavam parasitados por nematoides. As larvas de nematoides foram encontradas encistadas na serosa intestinal, apresentam na região anterior dois lábios com duas papilas cada, bulbo cefálico armado de 6 fileiras de espinhos descontínuos, quatro sacos cervicais, esôfago claviforme, estrias cuticulares ao longo do corpo, abertura anal simples, cauda curta, terminando em um mucron. A junção de todos esses caracteres morfológicos, são características diagnósticas para gênero Gnathostoma. Os indivíduos adultos são parasitos de estômago de mamíferos carnívoros e raramente de peixes, porém peixes, anfíbios, répteis e aves atuam como hospedeiros intermediários das larvas (L3) e o homem pode atuar como hospedeiro acidental.