Submission Type
Poster
Abstract
Chemotaxis describes the movement of an organism towards or away from a particular substance. Tardigrades are often thought to be lumbering organisms, not capable of seeking out nutrients and therefore unable to demonstrate chemotaxis. The ability to recognize foods and poisons in the environment and move up or down their concentration gradients appropriately is so beneficial for life that we suspected that tardigrades also possessed this ability. We constructed testing arenas where an agar block with concentrated test substance was placed on a water agar plate and incubated for two hours to establish a concentration gradient. Enough water was then added to allow for tardigrade movement, and one tardigrade (Hypsibius exemplaris) was then placed 0.5 cm away from the test agar block. We recorded tardigrade movement through a microscope, and then digitized movement tracks to quantify chemotaxis patterns. We tested multiple substances including the expected attractants Chlorella and Chlorococcus, and the expected repellents Tabasco, NaCl and mustard (Heinz). Patterns were inconsistent, but trends suggest that tardigrades can sense and respond to chemical signals in their environments. Movement away from repellents was more pronounced than movement toward attractants. We are continuing to optimize our arena design in ongoing research, and eventually plan to monitor chemotaxis in situ in more realistic environments.
Included in
Chemotaxis in tardigrades
Chemotaxis describes the movement of an organism towards or away from a particular substance. Tardigrades are often thought to be lumbering organisms, not capable of seeking out nutrients and therefore unable to demonstrate chemotaxis. The ability to recognize foods and poisons in the environment and move up or down their concentration gradients appropriately is so beneficial for life that we suspected that tardigrades also possessed this ability. We constructed testing arenas where an agar block with concentrated test substance was placed on a water agar plate and incubated for two hours to establish a concentration gradient. Enough water was then added to allow for tardigrade movement, and one tardigrade (Hypsibius exemplaris) was then placed 0.5 cm away from the test agar block. We recorded tardigrade movement through a microscope, and then digitized movement tracks to quantify chemotaxis patterns. We tested multiple substances including the expected attractants Chlorella and Chlorococcus, and the expected repellents Tabasco, NaCl and mustard (Heinz). Patterns were inconsistent, but trends suggest that tardigrades can sense and respond to chemical signals in their environments. Movement away from repellents was more pronounced than movement toward attractants. We are continuing to optimize our arena design in ongoing research, and eventually plan to monitor chemotaxis in situ in more realistic environments.
Comments
Kaleigh Falimirski, Xavier University