Effects of Cadmium, Copper, Chromium, Nickel, Silver, and Zinc on the Embryonic Development of the Starfish, Asterias amurensis

Abstract

The purpose of this study is to determine the sensitivity of developmental bioassay using Astrias amurensis (Phylum Echinodermata, Class Stelleroidea) to 6 metals (Cd, Cu, Cr, Ni, Ag, Zn). The concentration-response relationships between metals and the proportion of normal larvae of A. amurensis, and the EC50 for each metal were obtained. Experiments were conducted based on the standard bioassay protocol for sea urchins with slight modification. Morphological deformation from normal bipinnaria larva was evaluated after 72 hrs’ incubation at 15C.The LOECs for Cd, Cu, Cr, Ni, Ag, and Zn were 2000, 13, 2500, 375, 25, and 200 g/L, respectively. The proportion of normal larvae appeared to decrease linearly with the logarithm of each toxicant concentration within the tested range. The average values of EC50s from 3 separate experiments for Cd, Cu, Cr, Ni, Ag, and Zn were 5480, 20, 3857, 473, 56, and 343 g/L, respectively. The sensitivity of developmental bioassay with A. amurensis to the metals tested was following order: Cu>Ag>Zn>Ni>Cr>Cd. The embryo of A. amurensis showed the highest sensitivity to Cu, whereas, it showed the lowest sensitivity to Cd. In comparison of EC50 (or LC50) of Cu with other bioassays, the developmental bioassay with A. amurensis is less sensitive than the development of bivalves (Mytilus galloprovincialis, Ruditapes decussatus), comparable to the developments of oyster (Crassostrea gigas) and ascidian (Ciona intestinalis), but more sensitive than the development or the survival of crabs, shrimps, mysids or fishes. The sensitivity of the embryo of A. amurensis is intermediate among marine organisms commonly used in aquatic toxicity tests. Therefore, The developmental bioassay with A. amurensis may be applied to the toxicity assessments of marine environments of Korea