Another week has gone by and it’s been hard work. This week was filled with problems and problem solving. My cyprids wouldn’t swim, the math couldn’t be worked out, and excel spreadsheets were looking chaotic. Admittedly, this week was rather frustrating, but that’s all a part of science. After all, creative problem solving is a vital skill in the sciences, and this week gave me plenty of practice. The thing is, even when you have a hard week full of “failures”, you still learn a great deal from those failures, and discover fun things along the way.
Before the week began, Richard noticed that there was a flaw in the equation we were originally using to determine the density of a cyprid. In the original equation, we assumed that a cyprid’s depth was equal to the cyprid’s width, and we found a long, complex equation that was created based on that assumption. Then, Richard discovered a paper published in 2014 that showed that the cyprid’s width was, in fact, much smaller than their depth. Our assumption appeared to be flawed. So, this started a long trial of trying to find the right formula to get the most accurate density. A wild goose chase of nerdy proportions.
I started the algebraic journey by remeasuring my cyprids. I had to carefully roll each specimen onto its belly to take an actual measurement of its width. Then, I spent the rest of the day finishing up my preliminary sinking and swimming trials for my B. glandula cyprids. Monday was all about measuring, brainstorming, and rocking my little cyprids.
Tuesday is where the real trials started. With all the raw data in front of me, Richard and I had to figure out the new mathematical equation to use. I decided to go right at the source. I reread the paper that pointed out the flaw in our previous assumption and method, and I tried calculating density using their mathematical formula, which was a modified version of the Stokes’ equation. The Stokes’ equation is an equation that helps describe motion in highly viscous fluids. Think honey when you think of a very viscous fluid. I spent that day mostly inputting the data, calculating the new densities of my cyprids. As it turns out, there is a 10-point difference between the excess densities calculated with the old and the new method and this accounts for about 25% of their weight in water. I spent the rest of the day working on that spreadsheet, and then taking some breaks to work on my poster. I find that taking breaks from left-brain activities, such as figuring out math, to do more right brain activities, like organizing and designing an awesome poster, keeps me focused and prevents frustration.
Then, Wednesday rolled around. I was ready to move on to conducting more trials with my other study species, B. crenatus. As it turns out, B. crenatus are a lot harder to work with than B. glandula. The first issue is with collecting my specimens. B. glandula are very common in plankton tows, and they’re relatively easy to spot and identify due to their characteristic golden color. B. crenatus are a bit less common, and their translucent coloration makes them hard to immediately spot. At least they have a large red compound eye that helps me spot them. I conducted a plankton tow on Wednesday and I could not find any B. crenatus. In the meanwhile, I continued working on my poster and organizing my data.
Thursday is where everything complicated even more! Richard generously conducted a plankton tow early in the morning, so we may find some more test subjects, and we were able to find cyprids of B. crenatus. Invigorated, I conducted my swimming trials, only to find that all but two of my cyprids refused to swim. At best, a cyprid of B. crenatus will swim in a loop, but not at a great enough distance to allow me to measure their speed like B. glandula. I could at least measure sinking rates for B. glandula. Their “laziness” does appear to support one of my hypotheses about the difference between swimming activity between the two species.
After measuring sinking rates and body size in my B. crenatus cyprids, it was time to wade back into the mathematical jungle once more. This time, Richard and I realized that the 2014 paper failed to take the orientation of the sinking cyprid into account, which could affect density calculations. Our current solution is to take the average of depth and width of each cyprid and place that average into the old equation. Now the plan is to rework the data into this new method and see where my experiment goes from there. As for my “lazy” cyprids, I am looking far back into the literature, with a paper published in 1928 that describes the behavior of cyprids under various forms of light. Hopefully there I can find insights that will inspire my cyprids to finally swim. If after all that effort, if my B. crenatus cyprids still won’t swim, then that can still tell me something important, that B. crenatus are far less active than B. glandula.
It’s been a long week, but with enough determination and cleverness, I am optimistic about the rest of my time here!