عنوان مقاله [English]
This study was done on 692 specimens of Ship Sturgeon (Acipenser nudiventris) in International Sturgeon Research Institute Dr Dadman and Sturgeons rearing and propagation Shahid Beheshti hatchery from June to October 2007. A number of 23 specimens were identified from viewpoint of external lesions and samples were studied for bacterial agent's isolations. The observation showed the most content of lesions were related to scutes with abundance of 78.3%, skin (39.1%) and finally fin (8.7%). In bacteriological experiments, Aeromonas cavia (23.5%)and Acipenser lowffii (23.5%) had the most abundance (from total bacteria) and Pseudomonas flurescens and Enterobacter(sp) 2.9% had the least frequency. Also, Pseudomonas putida (14.7%), Aeromonas sobria(11.8%), Acetinobacter calcoaceticus (8.9%), Klebsiella oxytoca (5.9%) and Aeromonas(sp) with abundance 5.9% were come next. A.cavia in lesions of skin (25.1%) and scute (26.4%) had the most aboundance.In fin; A.lowffii (75%) had the most abundance. In this survey, all isolated bacteria were gram negative. With regard to existence of bacteria in lesions, the reason can be the water source in culture. So, health management is mandatory to keep water in good quality and suitable density and take a good care of it in order to control the bacterial agent.