Image analysis of daphnia is performed using RoboRealm software. Compare to heart beat counting, this method provide better data for the bio toxicity study.

1. Ahyun Son

2. Daphnia is widely used in biotoxicity study
The change of heart rate after in-taking toxic
substance is the measure of biotoxicity
Unfortunately, counting heat beat with naked
eye is not easy because it jumps around
continuously.
Fixing Daphnia on slide glass is also not a
good solution because it causes big stress to
the animal

3. Non-invasive measurement.
Fully automated
Big data, presented as time series curve
on 2-dimensional area, is generated that
can be further analyzed
Complex pattern can be visualized

4. Camera with close-up lens
Thin-layer cell made with
cover glass
(10mm x 10mm x 1.2mm
Computer for
image analysis
Daphnia
trapped in a
air bubble

5. Original
image
conversion Track center of
gravity
1. Download ‘Roborealm’ software
2. Make a script (see right)
3. Run the script, COG and time is saved
automatically

6. Made of cover glass
Daphnia lives for a long time
Thickness can be adjusted
Two cover glasses are sandwiched with
molten paraffin
Cheap and easy

7. Grow Daphnia in a aquarium
Feed Chlorella
Make mini aquarium with cover glass
Inject a Daphnia into it.
Seal the opening with paraffin
Put it on camera and run RoboRealm
Run the script and collect data
Feed different substance to Daphnia
Make a software that display the COG, time data as a 2D
curve

9. A Daphnia is left in the cell for 24 hours
A Daphnia is moving along the edge.
After 48 hours, mother
Daphnia is died. More than
ten baby daphnia are
hatched and gathered at
this area
A spike caused by error image analysis software

13. Image analysis may provide more useful
information of biotoxicity
Motion pattern could be analyzed if necessary

14. 1. RoboRealm : http://www.roborealm.com/tu
torials.php
2. Image processing software – provided by
Biolocs Co. Ltd. Korea