There are a number of strange creatures on our planet—organisms that are far from our everyday experiences. There are creatures that produce their own light, organisms that live in highly acidic locations, and some lifeforms that even fly through the air or live miles beneath the sea. And although it may seem like a cruel practice, using tracking devices in order to better understand these creatures is an important part of scientific research, and it's an important part of ensuring their overall survival.
If we want to mitigate and lessen our impact, the first step is understanding. So, when two students were tasked with injecting small tags into starfish in order to make them easily identifiable for research purposes, they set about their task dutifully. However, they encountered some problems.
Namely, it seems that these starfish do not want to be research subjects.
Or rather, they don't want foreign objects in their bodies (rather understandable, really). Ultimately, the students, Trine Olsen and Frederik Ekholm Gaardsted Christensen, students from the University of South Denmark in Odense, noticed that, after just a few days, the starfish were spouting out the tags. And what's perhaps most notable is that the tags were traveling around inside the starfish without hitting any organs causing harm.
"This is roughly equivalent to getting rid of a bullet lodged between your lungs by squeezing it out through your forehead, all without leaving a mark," says Daniel Levitis, the project supervisor. Levitis continues by noting that these creatures might be able to do the same with larger foreign bodies by, possibly, shedding a limb and regrowing it later (something that starfish are known for).
Although the complete mechanism isn't fully understood, the current findings are described in a paper published in The Biological Bulletin.
Watch the video below to see an awesome view of the students tracking the metal chip using a magnet (note: It's not in English, but it's a cool visual.)