Osmotic Strength

Set up test tubes with about a half an inch of each of the following solutions:

CONTROL

100% seawater
[CONTROL]
90

9 parts seawater and 1 part distilled water
80

8 parts seawater and 2 parts distilled water
70

7 parts seawater and 3 part distilled water
60

6 parts seawater and 4 part distilled water
50

Equal parts seawater and distilled water
  1. Add one drop of concentrated eggs to each.
  2. Swirl and let sit for one minute.
  3. Add one drop of diluted sperm suspension and swirl briefly.
  4. Wait 5 minutes.
  5. Score eggs for fertilization. If time permits can also score for later development [Next period see if divided. Next day see if there are swimming blastula.]