Development of a short-term chronic toxicity test with a tropical mysid

Abstract

There is an increasing need to develop reliable methodologies for chronic toxicity testing using tropical species. The present work aimed at developing a suitable short-term chronic toxicity test with Mysidopsis juniae using zinc (Zn) and nickel (Ni) as model chemicals and growth (length and dry weight), survival, and egg production (number of females with eggs) as endpoints after seven days of exposure. Survival and growth of newborn M. juniae were affected by chronic exposure to zinc, while nickel affected only survival. For zinc, dry weight was the most sensitive endpoint with significant effects even at the lowest tested concentration (75μgZn·L(-1)), whereas for nickel, survival was the most sensitive parameter (LC20 of 26μgNi·L(-1)). Egg production was not affected. M. juniae short-term chronic testing is a sensitive approach to evaluating metal toxicity; further studies are necessary to assess chronic toxicity for others contaminants in the proposed assay.

Keywords: Length; Metals; Mysids; Reproduction; Survival.