Transcript Preferences of lab-raised and wild Armadillidium vulgare exposed to

Preferences of lab-raised and wild Armadillidium
vulgare exposed to different colours of light
Kelsey Eatmon, Amie MacDonald and Elise Tessier
BIOL 3401
November 2013
Outline
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Background information
Goal of our experiment
Hypotheses
Materials and Methods
Results
Discussion
Conclusions
Background Information
• Pillbugs
– Terrestrial isopods
– Modified lungs
– Sensitive to high intensities of light
– Believed to be negatively-photosensitive
http://en.wikipedia.org/wiki/Armadillidiidae
Goal
• Determine if the photosensitivity of pillbugs
raised in the wild and lab-raised pillbugs will
increase as the wavelength of light decreases
Hypotheses
• Lab-raised pillbugs and wild pillbugs will prefer
the dark environments
• Lab-raised pillbugs will be less photosensitive
to a high intensity light than wild pillbugs
• Photosensitivity will increase as the
wavelength of light decreases
Materials and methods
• Wild pillbugs were collected by Silver Lake in
Sackville, New Brunswick
– Maintained in a dark
environment at an
outdoor temperature
Materials and methods
• Lab raised pillbugs came from the Animal
Behaviour Lab at Mount Allison University
– Maintained at room temperature
– Regularly exposed to the light from the windows
and the overhead lights (~340 Lux)
Materials and methods
• Experimental Design
– Elongated plexiglass chambers
– One lamp placed on either end of the chamber
– Filters used to produce the blue, yellow, and red light (43
Lux)
Materials and methods
• 10 wild pillbugs and 10 lab-raised pillbugs
tested separately
• Monitored under sequential combinations of
light colours
General preference of lab-raised vs.
wild pillbugs
Specific colour preferences
Visible light spectrum:
DARK → RED → YELLOW → BLUE →
Wild pillbugs:
DARK → RED → BLUE → YELLOW →
Lab-raised pillbugs:
• Did not show pattern
Discussion
• Acclimation
• Social Behaviour
– Aggregation patterns
http://www.floridapest.com/pest_guide/landscape-pest/sow-bug.html
Discussion
• Appearance of colours
– Blue appears darker than yellow
– Colours may not appear the same to pillbugs
• Compound eye
• Desiccation
http://www.flickr.com/photos/54475261@N02/6736802539/
Conclusions
• Wild pillbugs followed the predicted pattern
– Exception: blue and yellow
• Lab-raised pillbugs did not exhibit predicted
behaviour
– Acclimated to higher light intensities
Questions?