Acute toxicity (LC50) of a pesticide (Carbendazim) on two native crustacean zooplankton species: Daphnia pulex Leydig, 1860 and Tumeodiaptomus diabolicus (Brehm, 1935) from northern Patagonian lakes (Chile)

In Chile there is an increased use of fungicides, especially in the central and southern parts of the country. The aim of this study was to test the sensitivity of two common zooplankton species, Daphnia pulex Leydig, 1860 and Tumeodiaptomus diabolicus (Brehm, 1935) to the fungicide carbendazim. The specimens came from Lake Calafquén (southern Chile), and were subjected to bioassay experiments under laboratory conditions over 48 h to seven carbendazim concentrations (0-77.70 μ g/l); these bioassays were performed using adult specimens. In parallel, also literature information on the commonly used D. magna Straus, 1820, was used. It was found that T. diabolicus had a 48-h LC 50 of 28.1 μ g/l, while D. pulex had a 48-h LC 50 of 26.1 μ g/l, and finally D. magna has a 48-h LC 50 of 136.1 μ g/l. These results indicate that the two native zooplankton species of Chilean Patagonian lakes are considerably more sensitive to the pesticide carbendazim, than the species D. magna that is used as a standard.