First Gnathia sp. (Gnathiidae) Infestation on Labrus viridis (Labridae) in Türkiye

Abstract

Gnathiids are ectoparasites of elasmobranchs and teleosts. The adult stage of gnathiids is free-living, but has a blood-sucking parasitic form called praniza larvae. Gnathiid praniza infestations have been previously reported in numerous species of fish. In the current study, Labrus viridis collected from Izmir Bay, Aegean Sea, examined for parasite infestation. Gnathia sp. was found predominantly in the gills and mouth cavity of fish with a 58.3% prevalence. The samples were collected with fine forceps from the host and preserved in 70% ethanol and 10% formaldehyde solution for observation with a light microscope and scanning electron microscopy to identify parasites. Red and green-blue pranizas were detected, and the hindgut of pranizas showed differences from the attached place of the host.