1. How does water clarity and time of day affect color pattern detection?
Sally Feng*, Numan Karim**, Rebecca C. Fuller, Zoi Rapti
University of Illinois at Urbana-Champaign
*feng29@illinois.edu; ** karim3@illinois.edu
Introduction
The ability of bass to visually detect color can provide
individuals with a valuable survival advantage when
searching for food. There have been extensive studies
done to determine how well a bass can see such as
whether they see in color or in black and white. In this
study, we will examine the visual system on prey
preference by color of the largemouth bass (Micropterus
salmoides). Bass have been hypothesized to have a two
cone visual system allowing them to detect red and green
wavelengths. We will graph the wavelengths reflected
from the downwelling and sidewelling irradiance in two
water treatments: clear and tea-stained. The light
reflectance from a common prey of the bass such as the
bluefin killifish (Lucania goodei) will be used to calculate
the sidewelling irradiance. From there, we can compare
the wavelengths in the downwelling and sidewelling
irradiance to determine what colors bass are able to
detect. Information on the visual ability of bass to detect
color can lead to further studies to determine what color
lures attract bass.
AcknowledgementsConclusions
● Colors are essentially different wavelengths, so it is natural that we see the clear tanks
let most wavelengths through.
● The the tea colored tanks block out a lot of colors with wavelengths 400-500 nm
● Since we determined the prey preference by color of the largemouth bass, we can
establish which types of colors bass should most likely be able to see.
● This information can allow us to determine whether colors of lure have an effect on the
visual appeal for bass in which may be valuable information in assisting fishermen.
Clear water Tea-stained water
Predator-exposed mothers Unexposed mothers
Offspring of
predator-exposed
mothers x6
Offspring of
unexposed
mothers x6 We would like to thank the Illinois BioMathematics Program for funding our project. We
would also like to thank Dr. Rebecca C. Fuller and Zoi Rapti for their guidance in our project.
We like to thank the previous BioMath group: Shannon Stanis, Nicholas M. Sutton, Zachary
Turner for their data on the visual cone system of the largemouth bass.
• When producing eggs, females were either chased repeatedly by a
model predator (predator-exposed) or were left alone (unexposed)
References
Cummings, M. E. 2004. Modeling divergence in luminance and chromatic detection performance across measured divergence in surfperch (Embiotocidae) habitats. Vision
Research 44: 1127-1145.
Cummings, M. E. 2007. Sensory trade-offs predict signal divergence in surfperch. The Society for the Study of Evolution 3:530-545.
Downwelling and sidewelling radiances ( Id
, Ib
) were measured at 8am
using a spectrophotometer from wavelengths 400nm to 750nm.
Four water tanks were used:
The following two variables were measured:
● Downwelling irradiance:
Downward light from the sun.
The more photons emitted during a certain wavelength,
the more light is being reflected.
● Sidewelling irradiance:
Light reflected from background.
Methods
● Two clear water tanks labeled C1 and C2.
● Two tea-stained tanks labeled T1 and T2.