Some studies on monogenea infections in gills of marine water fishes in Egypt

الملخص EN

The present study was conducted to investigate the prevalence of monogenetic trematodes species.

Clinical signs, lesions and pathological changes appeared on diseased fishes were caught from Ezbet Elborg area (in corresponding to Mediterranean Sea), Damietta province in Egypt.

From 380 marine fish samples examined, 62 (16.31%) were positive for monogenetic trematodes.

According to fish species, Abu Seif (Xiphian gladius) was the most infected 12/50 (24%), then Loot (Argyrosomus reguis) was 10/51 (19.6%), then Morgan (Pagellus erythrinus) was 25/144 (17.36%) and lastly Makarona (Saurida undoquamis) 15/135 (11.11%).

Regarding monogenetic trematodes species were found to be most infected with more than one of monogenean species, Morgan (Pagellus erythrinus) 8/25 (32%) for (3) three infected monogeneans species while Loot (Argyrosomusregins) was infected with lowest monogenean species 2/10 (20%).

Seven species of monogenetic trematodes infect the infested fish (Diplectanum aequans, Macrovavitrema Caballera and Choriocotyl hysterocha infected Morgan (Pagellus erythrinus)), (Microcotyle chrysophrii and Diplectanum jerbuae infected Makarona (Saurida undosquamis)), (Pseudaxine trachuri) infected Abu Seif (Xiphian gladius) and (Diplectanum serrani infected Loot (Argyrosomus regius).

Seasonally, the highest infection of monogenean was in summer 23/85 (27.06%) and lowest infection in winter 10/100 (10%), also in spring 17/93 (18.28%) and autumn 12/102 (11.76%).

The clinical signs detected on infected fish include loss of appetite, scratching, excessive mucous secretion, ulcers, hemorrhage and respiratory disorders.

The pathological studies revealed severe pathological lesions, the changes include hyperplasia in mucous cells, necrosis of branchial epithelium and desquamation epithelial cells due to movement of parasites causing hemorrhage, edema and inflammatory reactions.

This study highlights on the prevalence of monogenetic trematodes in some marine fishes in Egypt causing high economic loss in wild marine water fish.