I never heard of them before. I came across a video late at night when I surfing the Internet on my iPad. As you say, cool, and unique. It was a lot of fun learning about them. I tried to get a better handle on the microbiome that allows them to digest algae. It's so specific. They can digest red and green, but brown is poisonous for them. When they are starving they resort to the brown and it kills them🙁. The articles dealing with this were really technical, but I did the best I could in covering the issue, given my limited science skills;))

Thanks so much for stopping by and commenting, @gabmr.