Selenium-lead interactions in crawfish (Procambrus clarkii) in a controlled laboratory environment

After exposure to selenium, the crawfish were still living in a complete state of paralysis for seven days. Duplicates were placed in pure water to determine the ability of the crawfish to purge the selenium and regain mobility. Within 24 h of purging, eighty-eight percent of the paralyzed crawfish had regained full motor skills. Analysis of the purged crawfish showed a significant decrease in the concentration of selenium in the chitin rich exoskeleton and gills. However, the lead concentration in the gills and exoskeleton of the purged versus non-purged crawfish did not show any significant decrease indicating that the bond between the chitin and lead is much stronger than the bond between the selenium and chitin and/or lead. Proposed mechanisms for each bond are presented in this research.