EFFECT OF MERCURIC CHLORIDE ON TOXICITY AND BEHAVIOUR OF FRESH WATER TELEOST ANABAS TESTUDINEUS

摘要

Static bioassays were conducted in the laboratory for 96 hours to determine the median lethal concentrations (LC_(30)) of mercuric chloride (HgCl_2) to Anabas testudineus. The LC_(30) of A. testudineus for 24,48,72 and 96 h were 6.01,3.2,1.8 and 0.96 ppm, respectively. Ten percent mortality at 96 h occurred in 0.18 ppm of HgCl_2, whereas 15,85,90 and 95 percent mortality were observed in 0.25.3.69,5.08 and 8.13 ppm, respectively. When A. testudineus was exposed to HgCl_2 for 96 h, fish exhibited a series of abnormal behavioural responses such as erratic movements, rapid movement of operculum, secretion of excessive mucus, jumping out of the test media, lateral swimming, loss of equilibrium etc: and finally the fish were found dead. It is concluded that HgCl_2 is highly toxic to A. testudineus.