Sharanya Entry #5-Final Two Weeks!!!

Even though I had to stay an extra week, I still can't believe that my EXP experience has officially come to an end. While I am sad that I won't be seeing my lab partners and friends anymore, I am still very satisfied with our group's results and most importantly, I am so grateful to have learned SO MUCH during my time there. During the two weeks, my group performed our last two sampling days and have been finalizing our results for my lab partner Anxhela's poster, which she had to finish and present on Monday of the next week. One of the major things I did was average out and plot the FIRe data, specifically the AL and MT measurements. The trends demonstrated that under light conditions, both Al and MT were increasing at a faster rate from 0 to approximately 300W/m^2 in irradiance, but then plateaued between 400 and 1000 W/m^2 and finally decreased from 1000 to 1400W/m^2. After discussing the resulting graphs with out PI's, we concluded that Noctiluca does prefer lighter conditions since the prey culture bottles in the light had way more cells (as indicated by the cell counts on the poster-image 2) than the ones in the darker conditions. Additionally, we also analyzed the final ammonia and chlorophyll measurements, which are an indicator of how much photosynthesis the cells were participating in. Initially we were confused as to why the cells were behaving this way but our PI soon determined that this was due to the cells dividing and therefore distributing the chlorophyll amongst two cells. Looking at the cell's preference for lighter conditions, we assumed that the cell preferred performing photosynthesis instead of phagotrophy since there was more light available and no need for it to feed on another organism. However when we looked at the prey counts, for which we used the FlowCam (image below), we noticed that the prey numbers were on the decline and that some culture bottles had very little to no prey at all. This is where it got interesting.

A VERY large clump of prey caught on the FlowCam!

Anxhela's poster (with my name on it;))

With its mixotrophic characteristics, Noctiluca is able to perform both photosynthesis and phagotrophy. Of course we all knew this but what we didn't know was that the two processes are not separated and are in fact interdependent, making it even more difficult to categorize this unique organism. Its ability to photosynthesize depends on its ability to feed and vice versa. I have personally never seen or heard of an organism behaving this way so this was definitely mind blowing.   The organism was thriving under light replete conditions not only because it had easier access to photosynthesis but also because easier access to photosynthesis allowed it to feed on the available prey species.

One of the many obstacles we faced while analyzing our data came from the FlowCam, which takes ten minutes to analyze each sample. This proved to be challenge when we had 120 samples of prey culture to filter through. Basically, the instrument is designed with a laser that detects individual prey cells and allows a tiny camera to capture images of them. Since there are thousands of prey cells in only 5mL of culture, it took a day and a half to get through one species of prey. While I did enjoy looking at the images of the prey, I eventually found this process, which mostly involved waiting for the culture to run through, the most boring part of the experiment. For one of the prey species Peridinium, we were afraid that we may have cross contaminated bottles since were were not seeing any Peridinium-like structures on the monitor. Instead, we were strange, round, spindle-like structures which were neither prey nor Noctiluca. After doing some research, our PI found out that the structures are actually Noctiluca, but in the form of cysts. Other dinoflagellates also form cysts usually when they are not reproducing during the winter seasons (image below). We are not yet sure on why the cells transform into cysts since there hasn't been much discussion about them in the marine biological community.

A dinoflagellate-Gonyaulax cyst

Finally after an entire week of sampling, averaging, and plotting (graphs), it was time for Anxhela and other undergrads to present their results to the entire observatory. The presentations themselves were only a minute long and took place in the Monell Building Auditorium. Afterwards, our lab and other students flocked to the Comer Geoscience building where the presenters would stand in a sort of Peddie Science Night configuration and explain the details of their findings.

Monell-the swankiest building at Lamont :)

Anxhela during her presentation 

Me, Anxhela, Kali (our technician), and Yen Sheng (another undergrad in our lab) during presentation night

After presentation day, we only had one more major sampling day on Wednesday. Since we didn't have time to go out to lunch, our PI surprised us by ordering sushi and BonChon chicken (I've never heard of it) takeout. We all sat together as a group and since another one of my PI's former grad students was visiting, he was able to join us for lunch too. Overall, our last sampling day went smoothly and we finished up what was left of the FlowCam prey cultures. Realizing that I was about to miss the shuttle (again), I said goodbye to my PI's and lab partners but promised to visit them later this month or in the fall.

I would first like to say that this has been an incredible learning experience for me. I am so grateful to Helga and Joaquim for welcoming me in to their lab and giving me this opportunity. I also realize how lucky I was to be a part of such a friendly and knowledgable group. I definitely would not have been able to accomplish what I did if it weren't for my fellow high school student Alexandria's friendship and my partner Anxhela's positivity and guidance. I realize that not everyone is lucky enough to truly bond with their lab groups but I am glad that I was. Going in, I was very shy and didn't really know much about this particular field or any of the methods that we were implementing. I was also making quite a few mistakes during the first few weeks and though my lab partner was more than understanding towards my inexperience, I was frustrated with myself. The first sampling day was probably my biggest challenge but it was also the most rewarding experience since that was the day I learned the most about our lab's procedure. However towards the end of these eight weeks, I was able to fully implement the protocols of the methods but also fully comprehend their purpose and the big picture of our study. Additionally, I was learning from my mistakes not only in the lab but outside of it as well. By getting lost in Harlem more than once, I learned how to travel in NYC's subway system. I also became a commuter for the first four weeks, traveling four hours a day through NJTransit, the Subway, and a forty minute shuttle. Ultimately this experience is something that I will always remember especially during my future scientific pursuits.

Last but not least, I would like to thank Dr. Peretz and Dr. Venanzi for giving me this amazing opportunity and for guiding me through to success. I would once again like to thank my PI's Joaquim and Helga for letting me be a part of their lab. Also, a BIG thanks to Kali our technician and go-to person for everything Noctiluca. I would also like to thank Alexandria, Yen Sheng, and Anxhela who helped make this an fun and unforgettable experience!

The Group-Yen Sheng, Alex, me, Kali, and Helga