Long-term Lethal Toxicity Test with the Crustacean Artemia franciscana

Summary

This study concerns the development and standardization of a valuable methodological protocol to determine long-term (14 days) lethal toxicity exerted by chemical substances, industrial wastewater or sewage and liquid environmental samples on the saltwater crustacean, Artemia franciscana.

Abstract

Our research activities target the use of biological methods for the evaluation of environmental quality, with particular reference to saltwater/brackish water and sediment. The choice of biological indicators must be based on reliable scientific knowledge and, possibly, on the availability of standardized procedures. In this article, we present a standardized protocol that used the marine crustacean Artemia to evaluate the toxicity of chemicals and/or of marine environmental matrices. Scientists propose that the brine shrimp (Artemia) is a suitable candidate for the development of a standard bioassay for worldwide utilization. A number of papers have been published on the toxic effects of various chemicals and toxicants on brine shrimp (Artemia). The major advantage of this crustacean for toxicity studies is the overall availability of the dry cysts; these can be immediately used in testing and difficult cultivation is not demanded^1,2. Cyst-based toxicity assays are cheap, continuously available, simple and reliable and are thus an important answer to routine needs of toxicity screening, for industrial monitoring requirements or for regulatory purposes³. The proposed method involves the mortality as an endpoint. The numbers of survivors were counted and percentage of deaths were calculated. Larvae were considered dead if they did not exhibit any internal or external movement during several seconds of observation⁴. This procedure was standardized testing a reference substance (Sodium Dodecyl Sulfate); some results are reported in this work. This article accompanies a video that describes the performance of procedural toxicity testing, showing all the steps related to the protocol.

Protocol

1. Method Standard

Our testing involves exposing Artemia larvae to an interval of substance concentrations or a test sample for the purpose of determining the concentration or dilution levels that would cause the death of 50% of the organisms (LC₅₀) exposed over 14 days and meeting the conditions defined by this method. If necessary and possible, the following may also be determined: a) the concentration level that causes the death of 20 % of organisms exposed (LC₂₀); b) the highest analyzed concentration level that does not determine a higher mortality rate than that of the negative control (NOEC); the lowest ....

Discussion

Artemia is one of the most valuable test organisms available for ecotoxicity testing and research done so far allows us to state that it is possible to sustain several options related to Artemia use in Toxicology and Ecotoxicology. The characteristics that turn this organism into a suitable species for bioassays are: a wide geographic distribution, high adaptability to adverse environmental conditions and varied nutrients, relatively simple laboratory culture and maintenance, resistance to manipulation,.......