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

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.Keywords: Gnathostoma, parasitism, estuary, puffer fish. ResumoO 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.Palavras-chave: Gnasthostoma, parasitismo, estuário, baiacu.

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

“…In addition, Gnathostoma sp. has been reported in tetraodontiform Colomesus Psittacus (Bloch & Schneider 1801) from Marajo ´Island (Pinheiro et al 2017).…”

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

“…(Silva et al, 2013); Rohdella amazonica (Giese et al, 2015), Gnathostoma sp. and Cucullanus marajoara (Pinheiro et al, 2017(Pinheiro et al, , 2018. All of these were intestinal parasites.…”

Zoonotic diseases of fish and their prevention and control

“…The parasites cause a disease known as gnathostomiasis, from the ingestion of infective larvae (L3) of the family Gnathostomatidae including Gnathostoma spinigerum , G. doloresi , G. hispidum , G. binucleatum , G. nipponicum and G. malaysiae as well as Echinocephalus sp. (Daengsvang 1981; Anantawat et al 2012 ; Pinheiro et al 2017 ; Shamsi et al 2021 ). Apart from hypo-allergic responses, the clinical symptoms of gnathostomiasis are similar to A. simplex but are normally more severe (Anantawat et al 2012 ) and include nausea, abdominal pain, and vomiting, which usually develop 24–48 hours after transmission.…”