A 7-D toxicity test for marine pollutants using the Pacific mysid Mysidopsis intii. 1. Culture and protocol development

Abstract

The purpose of this study was to develop a short-term (7-d) toxicity test for marine pollutants that is practical to perform at sites remote from a source of test organisms. Laboratory culture methods were developed that allowed successful long-term rearing of populations of the mysid Mysidopsis intii, a species indigenous to the Pacific coast of the United States. Mysidopsis intii was found to have a short life cycle of 20 d at 20°C, making it useful for chronic toxicity tests. A 7-d toxicity test was developed by comparing the sensitivities of various life stages of M. intii to sodium dodecyl sulfate (SDS). The most sensitive end point was found to be growth (final body length) of juveniles during the first 7 d after release. The sensitivity of mysids to SDS decreased with increasing age. To allow for shipping newly released juveniles to remote sites, a 7-d test was evaluated starting with 2-d-old mysids. The median lethal concentration for M. intii exposed to SDS at ages from 2 to 9 d was 4.59 mg/L (95% confidence limits, 4.21-5.00), and the maximum acceptable SDS concentration was 4.99 mg/L for both survival and growth.