Materials
- 2 male sea urchin
- 2 female sea urchin
- 20 gallons of water at room temperature
- 2 glass containers
- 15 cups of salt
- Fill each glass container with 10 gallons of room temperature water.
- Pour 10 cups of salt into one of the glass containers and label "Higher Sodium Level".
- Pour 5 cups of salt into the other glass container and label "Regular Sodium Level".
- Put 1 male and 1 female sea urchin into the both containers.
- Observe when they each couple mate and see which couple spawns first.