Keisha White |
SCHOOL: Alcorn State University
MAJOR: Biology/Pre-Medicine MENTOR: Dr. Stephen D’Surney EXPECTED GRADUATION DATE: May 2001
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ABSTRACT
Effects of Chlorpyrifos on the Zebrafish and the Mosquitofish
| Recent studies conducted by the Environmental Protection Agency (EPA)
have demonstrated that chlorpyrifos (trade name Dursban) exposure causes
harmful effects. Chlorpyrifos is a pesticide. It inhibits acetylcholinesterase
and in severe cases, can cause death. Due to harmful effects caused
by chlorpyrifos, EPA banned it on June 8, 2000. In this study, the
embryos of zebrafish (Danio rerio) were exposed to chlorpyrifos.
Zebrafish are freshwater fish found in the Cyprinidae family. They
are named for their characteristic light silvery and dark black stripes
that run horizontally on their body from head to tail. The zebrafish
were chosen for this experiment because of their ease of maintenance, the
speed at which they reproduce, and because their physical and genetical
structure is similar to that of humans.
In this experiment thirty embryos were exposed to chlorpyrifos concentrations of 50, 100, 200, and 400 in replicate. A control group was also used. The developing embryos were observed during the different developmental stages for mortality rate and developmental defects. We found that chlorpyrifos did have a profound effect on the fry (baby zebrafish) after they hatched. |