Gnathophis mystax, commonly known as the thinlip conger, is a benthic species inhabiting muddy or sandy substrates of the continental shelf and upper continental slope, typically between 80 and 400 m deep. This fish is distributed throughout the Mediterranean basin and the eastern Atlantic Ocean. It is a predatory species feeding mainly on benthic organisms and small fish, occasionally caught by deep trawl nets or longlines (palangres). Although its flesh is of good quality, it is not a target of specific fisheries and appears in markets only in small quantities.
Knowledge about the parasitic fauna of G. mystax is currently lacking. This study provides the first parasitological assessment of G. mystax from the southern Tyrrhenian Sea (Calabria, Italy), focusing on the presence, prevalence, and morphology of nematodes belonging to the genus Cucullanus. A total of 41 specimens of G. mystax were examined. The fish were collected along the Tyrrhenian coast of southern Calabria, specifically in the areas of Vibo Valentia and Gioia Tauro, provided by local professional fishermen.
Helminths were collected, mounted, photographed, preserved, and identified morphologically, including scanning electron microscopy (SEM) observations. The recovered nematodes were assigned to the genus Cucullanus and prevalence and mean intensity values were calculated. However, comparisons remain limited due to the absence of previous parasitological studies on G. mystax, underscoring the novelty and significance of these findings. Differences in host biometric data between the two sampling sites, and correlations between parasite abundance and fish length or weight, were also analyzed.
To our knowledge, this study represents the first record of Cucullanus spp. in Gnathophis mystax. The genus Cucullanus comprises a diverse group of gastrointestinal nematodes commonly parasitizing marine teleosts. This research adds valuable data to the parasitic biodiversity of Mediterranean fishes and provides a basis for future taxonomic and ecological investigations.
