Abstract:
A total of 120 marine fish as (Mullus barbatus) were collected from The Mediterranean Sea during the period from June 2021 to December 2021; they were dissected and examined for parasitic acanthocephalans. Only 29 (24.16 %) specimens were found to be Infected with Serrasentis sagittifer belonging to family Rhadinorhynchidae.
Infested fishes illustrate no pathognomonic signs except abdominal distension, whereas the infection was recorded in the intestine, pyloric ceca, and the external surfaces of some internal organs of the infected fish. Seasonally, the prevalence of infection was increased to 55.17 % during summer season and decreased to 31.03 and 13.80 % during Autumn and winter respectively.
Light and scanning electron microscopic investigation revealed that the adult worm was elongated (with broad anterior and narrow posterior ends) and measured 5.8–9.7 (6.9 ± 0.2) × 0.52–0.69 (0.58 ± 0.02) mm for male and 10.1–11.3 (10.8 ± 0.2) × 0.68–0.83 (0.72 ± 0.01) mm for female. Proboscis was long and cylindrical with a length of 0.89–1.3 mm (1.1 ± 0.2) for male and 1.11–1.19 mm (1.17 ± 0.02) for female. It was covered with numerous uniform spines arranged longitudinally as 9–11 rows each equipped by 15–18 spines. Spines were triangular, arrow-shaped, strong, and covered with cuticular theca; they decreased in size from the apex to the base of the proboscis. The proboscis was followed by a short spineless neck region followed by the body proper which was supported by multiple combs of spines (16–20) on its ventral surface. It was supported by the morphological data and the presence of trunk spines arranged within rows (comb-like) and the presence of four cement glands in the males. So, according to the records of morphological, the present parasite is classified as Serrasentis sagittifer belonging to class Palaeacanthocephala and family Rhadinorhynchidae with a new host record from the gilthead sea bream Mullus barbtus of the Mediterranean Sea.
