2. Preparing for Lab Session 1 of Response to Stimuli lab

In winter 2024, all groups will be working with pillbugs (Armadillidium vulgare) as the only or one of 2 study organisms (interspecies comparisons may be possible). You are going to practice making ad libitum observations of pillbugs and begin to come up with a list of behaviours that they display in a lab setting. Ad libitum sampling is valuable when you are introduced to new species and as a first step for identifying good research questions and formulating hypotheses.

You will use this information to help identify what behaviours are relevant to measure in the experiment you will be designing (session 1) and carrying out (session 2) (note: even if your focus is on physiological response to stimuli, you will also want to keep track of specific behaviours that are occurring). Two things to remember: organisms are always behaving, and keep your observations systematic and unbiased!

1. Watch the pillbug video (on eClass). Read the rest of #1 before you watch the video! There are 5 adult pillbugs in the petri dish. The soil in the dish came from the container they are housed in, so it is not a foreign material to them. The video is ~8 minutes long and you will split the observations into 2 segments (I have prompts in the video for when to start and what to be focusing on). Record the following information in your notebook:

a) For the first 3 minutes, reacquaint yourself with the pillbugs:

• Describe their general appearance
• How they move (i.e., what body parts are involved, is there a pattern of movement that appears “normal”)
• Movements around the dish (e.g., are they always along the edge?)
• Interactions with other individuals (e.g., how often do they occur, what do they look like, how long do they occur)

b) For the last 5 minutes, you are going to start your ad libitum observations. Without stopping or rewinding the video (i.e., pretend it is “real time”) record the following in your notebook – be as detailed as possible:

• Movements around the dish
• Interactions with other individuals
• All behaviours as they occur (e.g., do they bob their heads, wriggle vs. walk, etc.) – describe what you see and when it seems to occur.

2. From your background reading and after watching the pillbug video, list 2 biologically relevant stimuli that you would be interested in investigating in a lab-based experiment.

3. Now that you have those stimuli in mind and you’ve finished observing the pillbugs, set a timer for 2 minutes and write down, in your notebook, questions that you have relating to the stimuli and observations you made – what are you curious about? Write as many questions as you can in 2 minutes.

3. Star/highlight 1-2 questions that you think would be interesting to explore further. Be ready to share these with your research team!