Effect of sewage on blood parameters and the resistance against bacterial infection of goldfish,Carassius auratus

✍ Scribed by Kakuta, Izuru

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 110 KB
• Volume: 12
• Category: Article
• ISSN: 1053-4725
• DOI: 10.1002/(sici)1098-2256(1997)12:1<43::aid-tox7>3.0.co;2-8

✦ Synopsis

Effects of raw and treated sewages on blood parameters and on the resistance against bacterial infection of goldfish (Carassius auratus) were investigated. All fish exposed to 50% raw and 100% treated sewages died within 3 days. Plasma ammonia and lactate increased after 3 days' exposure to 10% raw and 20% treated sewages, though no fish died within 30 days. On day 30, the numbers of red blood cells, granulocytes and lymphocytes, activity of phagocytic cells, Hb, and plasma protein showed lower values than those of the control. Similar changes in blood parameters were observed in goldfish exposed to 5% raw and 10% treated sewages for 30 days, though to a lesser extent. No changes in these parameters were found in fish exposed to 5% treated sewage, whereas higher values for chloride, manganese, and bromide, and lower values for potassium and zinc, were observed on day 30, compared to those of the control. Fish exposed to 5% treated sewage for 30 days prior to an intraperitoneal challenge with Aeromonas salmonicida showed decreased survival rates. These results suggest that fish exposed to sewage, even to 5% treated sewage, are subject to suppression of the immune response.