Investigations Using a Digital Camera To Quantify Color Changes in Aiptasia pallida Due to Two Environmental Stressors: Heat

and Light

Presented by Presented by

Jennifer Welborn

June, 20111

Overview

•Background– Aiptasia as a model organism

•Procedure for Temperature Experiment

• Procedure for Light Experiment

•Sample ADI procedure– Rectangle Tool

•Sample ADI histogram

•Helpful Hints

Aiptasia as a Model Organism for The Effect of Global Environmental Change on Corals

Background

• Coral bleaching--serious consequence of global environmental change.

• Corals have a symbiotic relationship with algae

* algae provide food* anemone provides shelter

• Coral bleaching– corals are stressed by environmental factors, release algae, turn white and die

• Environmental stress factors• increased water temperatures (global warming)• lower pH (ocean acidification)• increased water turbitity (pollution effects)

Background Continued

• Aiptasia pallida -- small anemones similar enough to coral to be used as a model organism in labs.

• Unlike corals, Aiptasia are hearty and will not die if stressed to the point ofreleasing their symbiotic algae. They are able to get food by stingingand eating small organisms living in the water.

• Aiptasia -- can be used for coral bleaching research without harming them.

Aiptasia pallida The “bleached” Aiptasia on the right have released their algae due to environmental stress

Experiment 1: The Effect of Increased Temperature on the Color of Aiptasia Over Time

Research Questions• What is the effect of increasing water temperature on Aiptasia pallida? • Can we quantify a change in color that is related to the stress on an

organism using a digital camera?

Procedure1. 5 groups of 3 STEMDIGITAL participants set up the lab according to the

pupil page directions for temperature.2. Wait a few hours for the anemones to get acclimated.3. Create initial photographs according to the Using Your Digital Camera

as a Data Collection Tool directions given in the pupil page handout.4. Use the polygon or rectangle tool for the ADI analysis. Record R, G, B

values. Create a histogram of the data.5. Photograph the four anemones each day. Compare R, G, B values and

histograms to see constancy or change over time. 6. Compare data with other groups doing the same experiment.

Experiment 2: The Effect of Decreased Light on the Color of Aiptasia Over Time

Research Questions• What is the effect of decreasing light on Aiptasia pallida? • Can we quantify a change in color that is related to the stress on an

organism using a digital camera?

Procedure1. 5 groups of 3 STEMDIGITAL participants set up the lab according to the

pupil page directions for light. 2. Wait a few hours for the anemones to get acclimated.3. Create initial photographs.4. Use the polygon or rectangle tool for the ADI analysis. Record R, G, B

values. Create a histogram of the data.5. Photograph the four anemones each day. 6. Compare R, G, B values and histograms to see constancy or change

over time. 7. Compare data with other groups doing the same experiment.

Sample Spatial Analysis Using Rectangle Tool

Sample Histogram From Spatial Analysis Data

Helpful Hints

1. Trace the bottom of an empty petri dish on black paper for consistent placement of experimental dishes when capturing images

2. Use a tripod/ring stand for consistency. 3. Keep camera parallel to dish to avoid parallax.4. Remove lid from dish when photographing to

avoid reflection.5. Make sure there is label in each photo with date

and time.6. Make sure the bottom of each dish has been

labeled for identification in each photo. 7. Aim for consistency of ambient light.