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.

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.

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.