Experimental Tropical Marine Ecology

Around the Algal Globe
by -- April 4th, 2012

Day 6 (March 8, 2012)

We entered the lab with confidence, and our hearts filled with hope that this time (at 50% of the original odor cue weight) we would get significant results. We also changed the cue containers to small cones made from Kimwipes in order to increase the efficiency of odor diffusion. In the end we found that the crabs significantly went towards the conspecific odor cue which seemed to have indicated that our little guys were unhappy with their shells.

In the afternoon we decided to split into two groups: one to work on our visual cue experiments and another to go out snorkeling in the mangroves to collect independent study data. I, of course, was in the latter group and excitedly grabbed my snorkel gear along with Shannon and Abby, who was accompanying us to provide much needed extra hands. Because we were heading out without Humberto he equipped us with a cell phone and an emergency GPS mayday device which he swore would even bring the FBI to us should we turn it on. We certainly felt well cared for.

Humberto testing out the apparatus for the visual cue experiment

Data collection went well and I felt as though we were getting comfortable with our tasks as we got more experience. It allowed me to dispel the fear I had initially of being stung by any number of organisms such as jellyfish or fire sponge. I became patient and confident that as long as I followed a certain protocol, everything would be alright. And the results were worth the risks taken. We even got to see the really cool unicellular algae that Humberto had described to us and we had Googled in order to keep our eyes out for it.

I feel so lucky for getting to see this beautiful globe that is algae!

When we were preparing to leave our data collection site Arnulfo, our awesome all-knowing local boatman and ecologist (he knew where all the Thalassia beds could be found), pointed out a jellyfish along the side of the boat. Because we insisted that we couldn’t see anything for an entire minute he whipped out a hose and started nudging the still invisible jellyfish closer. Splash! Fulfo dipped his hand in and scooped up the jellyfish, his experienced hands taking care to keep his palm on the top of the jellyfish by holding it upside down. Now that we had seen the elusive jellyfish and he threw it back in.

What a brave man! We had had enough of jellyfish though they still had the abililty to fascinate lol

On our arrival back to the lab we were cheered to see that they were almost done with all the visual cues experiment. Apparently everything had gone smoothly with significant results. We therefore excitedly went home to shower and change before dinner after which we would return to the lab to do volumetric and weight analyses of the crabs and their shells. Abbie and I formed the crab torture team (we greatly resented being called torturers). Our job was to get the crabs to willing leave their shells by making them hot. The process was mostly quick and not too stressful for them, we hoped. We also hoped that the soothing voice of Adam Levine coming from Abbie’s voice helped calm them after the ordeal we put them through. After this process was completed the other group separately measured and recorded the weight of the crab and their shell. We also measured the volume of the shell by taking the difference between the weight of the shell and the weight of the shell filled with water and the volume of the crab by measuring the water it displaced when submerged in a known volume in a marked vial. It took us awhile to get into a rhythm and when we got the hang of it we figured it was time to call it a night at 12:30am and better to start afresh the following morning bright and early.

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