This study was conducted on 224 marine fish belong muglid species 
namely; Mugil cephalus, M. capitus, and M. seheli randomly 
collected from fish farms during the year 2015 in Damietta 
Governorate, Egypt. Most of the clinical signs of these fishes were 
recorded. The clinical examination revealed hemorrhagic spots in 
the areas of the head, abdomen, tail, around the mouth, and anus.
Some of fishes showed paleness in gills and showed a mosaic 
appearance on the gills. The percentage of Caligus sp. was 
recorded in M. cephalus (7.94%) , (11.65%) in M. capitus and (0%) 
in M. seheli. Seasonal prevalence and Light and Scanning Electron 
Microscopic identification have been carried out