In an article by Kim Krieger titled "The Fortunate Ones?", you can read about why the horseshoe crab's blood is so valuable. You can also find out where you can go to see PhD student Kate Castellano feeding horseshoe crabs in a tank decorated like the town of Bikini Bottom.  Dr. Rachel O'Neill, key faculty in the Health Care Genetics program provides the story as to why “Weird animals" are valuable models to  understand species diversity and adaptation to Earth’s diverse environments.  https://magazine.uconn.edu/2019/06/05/the-fortunate-ones/