A study on the effects of four heavy metals on five species of chironomous larvae present on Mahe Island of Seychelles

摘要

A study was conducted on the island of Mahe, Seychelles, on five species of chironomous larvae endemic to the island. The chironomous larvae were exposed to four heavy metals-copper (Cu), cadmium (Cd), mercury (Hg), and zinc (Zn), for a 96-hr period, and the LC_(50) values were calculated. It was observed that the most sensitive species of chironomous larvae was Gymnometriocnemus mahensis. The least sensitive form of chironomous larvae examined was Paramerina minima. The 96-hr LC_(50) values obtained for Tanypus complanatus for Cu, Cd, Hg, and Zn were 1.9 (1.73-2.09), 1.35 (1.17-1.57), 0.33 (0.26-0.43), and 28.96 (27.03-31.03) ppm, respectively. Similar results were obtained for other species studied.