dissected out my last COT ovaries,
(Notice how the spines have been trimmed both for my protection and to mark the individual. This is female #4 because she has spines trimmed in all four quadrants.)
...and put the ovaries in a convenient food storage container used to transport the ovaries across the street to the lab:
After the lid was put on the container, I found the right male (each cross is between a specific female and a specific male so that we can investigate if different parents make a difference in fertilization success), removed some testes....
...and put them in their own container where they immediately began leaking milky clouds of sperm.
Eggs and sperm were put in the experimental tubes by mid-morning. I let them develop until around 6 p.m. when I preserved them. After dinner I went back to the lab to start analyzing not only these tubes but also the many others that I had been accumulating from the six new experiments we conducted over the past several days. It was important to examine them quickly as we didn't want to turn off the CO2 system until we knew all the experiments produced satisfactory results. So after an evening in the lab, I returned by 6:30 a.m. this morning and continued processing. It wasn't until 6 hours later that I finally finished looking all the tubes:
I categorize 200-300 embryos (or unfertilized eggs) from each tube under the microscope. Although a bit arduous, it is never tedious because it is so fascinating to see the process by which sea stars develop, even though some of the embryos are abnormal.
All three embryos seen here have a clear fertilization membrane around them. The embryo with the large cells at the upper left is abnormal, whereas the other two are a normal "late blastula" which is basically a hollow ball of cells.
Having run 24 fertilization experiments, with 16 of them giving us good enough results to further analyze statistically after we get back, we were happy to start the process of shutting down the CO2 system and cleaning out the aquaria. It will be a huge relief not having to oversee and maintain all the equipment everyday, but a bit sad to think that our days of working with live Acanthaster are nearing an end.
Still, we wanted to celebrate the end of our COT fertilization experiments, so we choose an interesting roadside pizza restaurant for a delightful dinner...
...culminating in a silky smooth homemade Belgian chocolate mousse for dessert. (Sorry, no pictures of this sublime creation were taken for we were too busy indulging!)
No comments:
Post a Comment