Analysis of chemotaxis and phototaxis in planaria
School Name
Southside High School
Grade Level
12th Grade
Presentation Topic
Zoology
Presentation Type
Non-Mentored
Abstract
Planaria are simple flatworms, but they possess primitive eyespots that can detect certain chemicals. In this work, we describe their response to both positive and negative chemical stimuli. Planaria were isolated and placed in a container of water. Then, either a piece of chicken liver or a salt water solution was introduced to the planaria’s environment. The planaria were then observed over time to allow for the chemicals to diffuse and create a concentration gradient. Previous studies have indicated that planaria display positive chemotaxis in response to chemicals found in chicken liver, and negative chemotaxis in response to salts such as the NaCl solution.The planaria’s changes in speed and direction of motion were recorded and compared to a baseline average obtained in the absence of chemical stimuli. This was analyzed by using a coordinate system in the planaria’s environment to establish a frame of reference and videotaping the planaria. A decrease in rate of movement typically indicates distress from the planaria, while increased speed typically indicates a positive response to the environment. Previous studies have indicated that planaria display negative phototaxis in response to light, but their ability to detect the light varies based on the wavelength. Eyespots tend to be more sensitive to light of shorter wavelengths. Filters were used to isolate wavelengths of light of around 450-500 nm and of around 750-720 nm, and a concentrated beam of light was shone in the planarian’s environment, The planaria’s changes in speed and direction of motion were recorded and compared to a baseline average obtained in the absence of the stimulus of bright light. This was analyzed by using a coordinate system in the planaria’s environment to establish a frame of reference and videotaping the planaria. A decrease in rate of movement typically indicates distress from the planaria.
Recommended Citation
Beaudoin, Katie and Sama, Vineeth, "Analysis of chemotaxis and phototaxis in planaria" (2015). South Carolina Junior Academy of Science. 129.
https://scholarexchange.furman.edu/scjas/2015/all/129
Start Date
4-11-2015 10:45 AM
End Date
4-11-2015 11:00 AM
Analysis of chemotaxis and phototaxis in planaria
Planaria are simple flatworms, but they possess primitive eyespots that can detect certain chemicals. In this work, we describe their response to both positive and negative chemical stimuli. Planaria were isolated and placed in a container of water. Then, either a piece of chicken liver or a salt water solution was introduced to the planaria’s environment. The planaria were then observed over time to allow for the chemicals to diffuse and create a concentration gradient. Previous studies have indicated that planaria display positive chemotaxis in response to chemicals found in chicken liver, and negative chemotaxis in response to salts such as the NaCl solution.The planaria’s changes in speed and direction of motion were recorded and compared to a baseline average obtained in the absence of chemical stimuli. This was analyzed by using a coordinate system in the planaria’s environment to establish a frame of reference and videotaping the planaria. A decrease in rate of movement typically indicates distress from the planaria, while increased speed typically indicates a positive response to the environment. Previous studies have indicated that planaria display negative phototaxis in response to light, but their ability to detect the light varies based on the wavelength. Eyespots tend to be more sensitive to light of shorter wavelengths. Filters were used to isolate wavelengths of light of around 450-500 nm and of around 750-720 nm, and a concentrated beam of light was shone in the planarian’s environment, The planaria’s changes in speed and direction of motion were recorded and compared to a baseline average obtained in the absence of the stimulus of bright light. This was analyzed by using a coordinate system in the planaria’s environment to establish a frame of reference and videotaping the planaria. A decrease in rate of movement typically indicates distress from the planaria.
