Effect of salinity on the locomotion of Caenorhabditis elegans

Abstract

Wild-type Caenorhabditis elegans have previously been observed to avoid high concentrations of NaCl and move away from highly concentrated sources (Khanna et al. 1996). In this experiment, the locomotion and change in rate of movement of the N2 wild-type nematode Caenorhabditis elegans was studied at different salinities. Three different concentrations of NaCl buffer solution, 0.0M, 0.5M, and 1.0M, were applied to C. elegans with 16 replicates for each concentration. Each replicate was observed as their speed and movement was recorded for 30 seconds, with the DinoXcope. They then were exposed to a specified concentration treatment and were left to acclimatize for 30 minutes before being recorded for another 30 seconds to track any changes. Using the software WormLab, measurements of the overall change in movement and changes in speed were obtained. When exposed to 0.0M NaCl buffer solution the average change in speed was -1.81 µm/s, when exposed to 0.5M NaCl buffer solution the average change in speed was -10.55 µm/s, and when exposed to 1.0M NaCl buffer solution the average change in speed was -84.65 µm/s. Although the average speed and movement decreased as NaCl buffer solution concentration increased, statistical analysis showed that there was no significant difference in the means. Therefore, we concluded that increasing salinity does not significantly decrease the rate of movement of C. elegans