Morphological, ecological and histopathological studies of Trichodina gobii Raabe, 1959 (Ciliophora: Peritrichida) infecting the gills of Solea aegyptiaca

Specimens of Solea aegyptiaca caught from Ghar El Melh lagoon in Tunisia were investigated for trichodinid ectoparasites. One species of the genus Trichodina was recorded on the gills of S. aegyptiaca. This species is identified as Trichodina gobii Raabe, 1959 which is reported for the first time on the soleidae fishes from Tunisian waters. The prevalence and the mean intensity level of these ciliophorans varied throughout the year with maximum rate of infection during the winter. Taxonomic descriptions of this species based on silver nitrate method and scanning electron microscopic observations are provided in this paper. Histopathological examinations of gills infested with T. gobii, revealed several lesions such as hyperplasia and lamellar epithelium lifting of the secondary lamellae.