Caracterização taxonômica e primeiro registro de Synhimantus (Dispharynx) nasuta (Nematoda: Acuarioidea) em Porphyrio martinica (Gruiformes: Rallidae) no sudeste brasileiro

Abstract

Synhimantus (Dispharynx) is a subgenus of nematodes belonging to the family Acuariidae that parasitizes several bird species; however, there are still gaps in knowledge regarding its occurrence in representatives of the family Rallidae, which are, in principle, potential hosts. The present study aimed to characterize morphologically and morphometrically specimens of S. (Dispharynx) found in Porphyrio martinica (Linnaeus, 1766), representing the first record of this parasite in this host in the southeastern region of Brazil. The helminths were obtained through the necropsy of a specimen from the Wild Animal Screening Center (CETAS/IBAMA) in Juiz de Fora, Minas Gerais, Brazil. Six nematodes were recovered from the proventriculus, consisting of three males and three females. Identification was performed through light microscopy analyses and comparison with descriptions available in the specialized literature. The examined specimens showed greater compatibility with S. (Dispharynx) nasuta (Rudolphi, 1819), and although some measurements differed from the values described in the literature, these variations were not sufficient to invalidate the identification, since the cephalic cords, deirids, and reproductive structures, considered important diagnostic characters, remained consistent with S. (Dispharynx) nasuta. Some individual morphological variations observed suggest caution in the isolated use of diagnostic characters and reinforce the need for integrative taxonomic approaches. Despite the limitations resulting from the small sample size, this study expands knowledge of the parasitic diversity of neotropical birds and provides a basis for future taxonomic and ecological investigations of Synhimantus (Dispharynx) nasuta.