Hello Foldscopers!

The intertidal is always an amazing habitat to visit. And sometimes you stumble upon a something that is even more exciting than the norm.  When my class arrived at Point Piños, we observed lines of purple in the sand (picture below).  Looking closer, I saw they were actually thousands of Velella velella, known as by-the-wind-sailors.  These are small carnivorous cnidarians, blueish or purple in color with a vertical sail on the body. They are typically found in warmer, high seas of the Pacific Ocean. These organisms are often brought closer to shore by wind. Unfortunately, once these wash ashore, they die on the beach.

I was able to look at one of the V. velella under my foldscope! First, I wanted to look the relatively clear sail. What I found were small green cells. Upon further research I found that although these organisms can sting their prey, they house algal symbionts in their tissues as well.

With such amazing results, I decided to look at the body of the V. velella as well. There was a lot more of the algae in the walls of the body.  Also, the purple/blue hue was very noticable. The rings that are visible on the body were also detectable using the foldscope!

While I was exploring the tidepools, I also found a broken purple urchin (S trongylocentrotus purpuratus ) test. A test is the radially symmetric internal skeleton of an urchin. This test is covered with large spines. These spines are used in conjunction with tubefeet for locomotion and to shift food closer to their mouth.

I took one of the small spines to look at under my foldscope. As I looked at the spine, I found I could see striations on the spines. This structure protects the  central core of the spines from fracturing when impacted.

On to the next adventure!