Physiological response of carp,Cyprinus carpio, exposed to raw sewage containing fish processing wastewater

Abstract

Physiological changes of carp exposed to raw sewage were investigated by the use of clinical examination methods. All carp exposed to raw sewage died within 6 h. On hour 48, 10, 40, and 90% of exposed carp survived in 60, 20, and 10% sewage, respectively. Carp exposed to 50 and 20% sewage increased ammonia, glucose, Mg, Cu, and Br, and decreased Fe and Zn in plasma. Even in 10% sewage, ammonia, glucose, and Br in plasma increased. Forty-eight hours of exposure to 50 and 20% sewage caused severe pathological changes in the gills. In the kidney, light abnormalities were observed at this time. When exposed to 50 and 20% sewage, atrioventricular conduction time and duration of electrical systole measured by electrocardiogram shortened briefly, and then extended gradually. In 50 and 20% sewage, heart rate and respiratory frequency increased briefly, and then decreased gradually. Cough reaction increased with the exposure. © 1997 by John Wiley & Sons, Inc. Environ Toxicol Water Qual 12: 1–9, 1997