Abstract

PEREZ-LEGASPI, Ignacio Alejandro; GARATACHIA-VARGAS, Mariana; GARCIA-VILLAR, Adriana Marisol  and  RUBIO-FRANCHINI, Isidoro. SENSITIVITY OF THE TROPICAL CLADOCERAN ceriodaphnia cornuta TO HEAVY METALS. Rev. Int. Contam. Ambient [online]. 2017, vol.33, n.1, pp.49-56. ISSN 0188-4999.  https://doi.org/10.20937/rica.2017.33.01.04.

Cladocerans have been used as test organisms to assess the adverse effects of pollutants in aquatic systems. Both Daphnia magna and Ceriodaphnia dubia are among the most commonly cladocerans used in aquatic toxicity tests. However, they are inadequate to assess tropical aquatic ecosystems. Ceriodaphnia cornuta is a common organism in tropical waters which tolerates variations in temperature, and is widely distributed in several wetlands. In this study, we evaluated the sensitivity of C. cornuta to heavy metals: lead, copper, cadmium, aluminum, and chromium by means of lethal toxicity tests. The Lethal Concentration 50 (LC50) at 48 h, both nominal and real values for lead, cadmiun, copper and chromium are (0.05, 0.06), (0.031, 0.027), (1.58, 1.54), (0.02, 0.02) and (1.12, 1.16) mg/L, respectively. This cladoceran was highly sensitive to low concentrations of copper, cadmium and lead, although it was not very sensitive to aluminum. The LC50 48 h values for C. cornuta exposed to copper, cadmium, and lead are lower than those LC50 reported with other cladoceran species used in lethal toxicity tests, showing greater sensitivity than D. magna and C. dubia , even being comparable to that reported for other tropical cladoceran species. In conclusion, C. cornuta might be considered as a test organism ,suitable for the monitoring of tropical coastal ecosystems contaminated with metals such as copper, cadmium and lead present in the Gulf of Mexico.

Keywords : Daphniidae; heavy metal; acute toxicity; ecological relevance.