5 November, 1998

Thursday November 5, 1998

Greetings from about 77 degrees S and 167 degrees E, Ross Island, Antarctica

The wind has picked up today so I expected to be greeted with a blast of freezing air when I left my dorm but it was surprisingly warm. The clouds look like they are building up. My view from the Crary lab computer room shows the peak of Mt Discovery (about 40 miles away) covered in clouds and the Royal Society Range (about 50-80 miles away) barely visible. As I walked from my dorm to the cafeteria I couldn't see the sea ice because of the snow being blown along the "ground". I imagine this would've made snow-mobiling quite difficult. Today we have planned a fishing trip to Granite Harbor by helicopter. Considering the wind, I don't know if that plan will still go through. Yesterday was another day of learning and practice. At snowmobile school I learned practical things like how to find out what is wrong if the snowmobile won't start and what to do about it, how to keep from spinning out on ice patches and what to do if it happens, and how to protect the snowmobile from the wind-blown snow when a "Herbie" hits. (A "Herbie" is blizzard with hurricane force winds.)


A few hours after Dr. Petzel injected one of the fish with the fluorescent DASPEI dye he "sacrificed" the fish and harvested the gills. Then I tried to figure out the best way to observe, count, measure, and photograph the chloride cells in the gills. In the microscope, the green chloride cells glowing brightly against the black background looked like constellations of stars in the sky. It was pretty neat. But as is almost always the case in biology, an experiment that looks neat and easy on paper is not so neat and easy when it comes down to doing it. Gills have a series of gill arches. Branching off of these arches are fine feathery filaments called lamellae. Branching off of these lamellae are even finer filaments called secondary lamellae. All of this feathery branching provides more surface area for the gills to more efficiently do their job of absorbing oxygen, getting rid of carbon dioxide, and controlling salt balance and blood pH (how acidic or basic the blood is). The chloride cells are on these secondary lamellae and between them along the lamella. The problem is that the lamellae and secondary lamellae are not flat like a feather, they have a curl to them. In high power magnification on the microscope, this curl makes it impossible to get an entire secondary lamella in focus so I can't see all of its chloride cells. The lamellae also overlap making it very difficult to tell where one lamella starts and another one stops. I tried finely chopping some of the gill but that didn't solve the problem. Any free-floating secondary lamellae tended to coil up and I also couldn't know if that was an entire secondary lamella or not. I tried flattening part of a gill between two thin glass cover slips to get rid of the three-dimensionality problem, but that either squashed the cells, spewing their contents out into the surrounding water, or it made it harder to count by folding the curl underneath or squishing one secondary lamella against another. Though I could never see an entire lamella clearly enough to count the chloride cells, I could see sections of them well. After consulting with Dr. Petzel, we decided that in this situation it would be best to take two measurements: cell size, and density of cells (number of cells/filament length)wherever I could see clearly. This is not ideal but is better than nothing. I will probably also try to figure out ways to measure the length and width of secondary lamellae. All of these measurements should enable us to find out if the warmer temperature fish are increasing the work done by Na/K-ATPase by having bigger cells, more cells per surface area, longer lamellae and secondary lamellae (more surface area), or none of the above.

While doing this process I also shot several black and white photos of the different views to further analyze them. Developing black and white film is a simple process but I still made two stupid mistakes so the negatives didn't turn out very well. It's a good thing they were just practice.

Another possible problem we encountered is that so many of the cells in the gills were glowing green that possibly too much dye had been injected so that other gill cells like mucus cells and pavement cells may have absorbed enough DASPEI to glow. Dr. Petzel said he would try changing the amount he injects next time.

This is part of the fun and challenge of doing science. The difficulty is the deadline. I need to have results from this part of the experiment on 6 cold-water fish and 6 warm-water fish by a week from today so that Dr. Petzel can write an abstract (summary) of the results for a presentation he wants me to give at a physiologists' meeting in Washington DC next April. To write that abstract he needs my data.

Well, that's all for now.

I hope you have a good day and do something good for someone. Fred Atwood.



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