Sea stars are much stranger than we imagined. Biology students at the University of Southern Denmark implanted a group of the animals with microchips and went about their business. When they checked in days later, the chips were lying on the floor of the sea starsâ tank.
The students realized that the sea stars had spit the trackers outânot through the original implantation sites in their skin, but through the tips of their arms. As Mary Beth Griggs notes in Popular Science , âThat would be like a human getting shot in the leg and then ejecting the bullet from their fingers without any internal injuries.â
Rather than getting frustrated, the young biologists put their scientific curiosity to work and decided to conduct formal experiments to better understand the animals' behavior. The researchers microchipped another 53 sea stars and monitored them using ultrasound scanners, watching the animalsâ bodies to see where the chips were going.
What they saw was strange. The chips moved through the sea starsâ bodies at a rate of about 10 percent of the distance from entry to exit point per day, but the route they took was far from direct. First, they were sucked into the sea starsâ body cavities. From there, they took what the researchers call âa somewhat haphazard wanderâ through the body, down the arm, and out the tip. Itâs hardly an efficient process, and it took about 10 days, but it did workâand the sea stars didnât appear to be hurt or distressed as they did it.
Like so many discoveries about the natural world, these findings raise more questions than they answer. Why would an animal need to do this? Why donât they just spit out foreign objects from the same holes they came in? How are they even doing this?
One question, at least, has a very clear answer. Are sea stars bizarre , wonderful, alien monsters ? Yes. Yes, they are.
[h/t Popular Science ]
Loading recommendations... Please wait while we load personalized content recommendations