Tolerance against exposure to solution of magnesium perchlorate in microinvertebrates

Abstract

Abstract Perchlorates are present at high concentrations in Martian regolith and pose an additional challenge to the survival of terrestrial life on Mars. Some microinvertebrates can resist extreme conditions (e.g. low temperatures, lack of oxygen and radiation), making them suitable model species for space experiments. Clarification of whether they can tolerate high levels of perchlorates is crucial for understanding the scope of application of small invertebrates in Mars exploration. We assessed the activity of some Crustacea, Nematoda, Rotifera and Tardigrada exposed to 0.25–1.00% magnesium perchlorate. The number of active specimens decreased with exposure time and perchlorate concentration. However, exposure of selected species to 0.25% perchlorate for 24 or 72 h showed activity in some specimens. Only Caenorhabditis elegans, Lecane inermis and Artemia salina exhibited activity after 24 h exposure to 1.00% perchlorate. Lecane inermis was the only species to remain active after 72 h of incubation with 1.00% perchlorate. Transferring specimens to distilled water after perchlorate exposure generally resulted in high recovery rates. The study indicates that all the tested invertebrates resist extremely high concentrations of perchlorates, which has implications for further research on their potential use in development of biological systems with improved performance and utility on Mars.