A preliminary study on ulcerative skin lesions in Sea - Caged Grouper (Epinephelus coioides)

Abstract

A low incidence mortality (15%) was observed in sea-caged grouper (Epinephlus coioides) in the Persian Gulf (Mahshahr, Khouzestan) following introducing the fishes to the cages in December 1993. Clinically, the affected fish showed multiple-round Skin lesions, penetrating to the underlying muscles, ulceration of jaws, fin and tail rot and opacity of eyes. Results of bacteriological study indicated that the organism isolated from the lesion belonged to the genera Pasteurella, Aeromonas and Streptococcus. Treatment of infected fishes with Halamid (N.sodium-N-chloroparatoluene sulphonamide) at 8 mg/lit for one hour of tank water as bath, together with topical cleaning of lesions by Betadin solution resulted in improving of the condition. Mechanical damage and improper water exchange suspected to be the predisposing factors for occurrence of the condition.