Yet another talent of the starfish (Asterias rubens) has been unveiled by biology students from the University of Southern Denmark: the creature can squeeze foreign particles out of its arm tips. This new research is expected to help explain how some animals can heal themselves relatively quickly.
A starfish seen squeezing a foreign object through the tip of its arm. Photo credits: University of Southern Denmark.
Two biology students, Frederik Ekholm Gaardsted Christensen and Trine Bottos Olsen, observed a phenomenal behaviour of the starfish, Asterias rubens; this trait has hitherto remained undocumented in scientific literature.
They had to tag the Asterias rubens so that researchers could reidentify and study the starfish. These tags were inserted into the animal. However, a strange response was eventually observed when the students injected the foreign objects into the creature.
“But every time we put a tag into a starfish, they rid themselves of the tag within a few days. It came out directly through the skin; the starfish simply pushed it out through the skin at the end of one arm and then went on as if nothing had happened”, say the two students.
While many organisms can oust foreign particles from their body in certain circumstances, they cannot do so when the object is too deeply ingrained inside them, such as a bullet between the internal organs. That’s where the starfish seems to be markedly different. It did not remove the tag through the hole where it was injected. Rather, the tag apparently wandered randomly in between its organs for some time and was ultimately squeezed out through an arm tip. The researchers explain that the tag passes through its body cavity to reach the tip.
Starfish has been documented to regenerate whole limbs as well as organs in the past. But, this new trait of pushing out deeply embedded foreign objects was never seen before – not even in another organism.
Find a video depicting the phenomenon below:-