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Coscinasterias tenuispina, Variable starfish or Spiny starfish is an echinoderm very common in the Mediterranean Sea. It is one of the most common starfish in the “Mare nostrum” and I would also say one of the most fascinating. Usually Echinoderms (sea urchins and starfish) have a pentaray symmetry. This species is indeed variable! It can have five but also seven or nine arms, always in odd numbers.
Blue spiny starfish Coscinasterias tenuispina Stella marina variabile www.intotheblue.it
As you can see, this specimen has three of the seven arms much smaller than the others, this is probably because it encountered a predator that detached them to feed on them. Our variable starfish, as you can see, manages to regenerate them without too much effort, but the peculiarity is that when an arm is cut off, a new starfish can be recreated that is the same as the original, or with the same DNA, therefore it is one of the rare examples of natural cloning.
Blue spiny starfish Coscinasterias tenuispina Stella marina variabile www.intotheblue.it
Variable Starfish or Spiny starfish (Coscinasterias tenuispina Lamarck, 1816) is an echinoderm of the Asteriidae family, common in the Mediterranean Sea.
Characteristics
Irregular shape with variable number of arms, from 6 to 12 (usually 7), with a diameter of up to 20-25 centimeters. The body is characterized by spines, of variable color white, gray, brown, red and sometimes blue.
Distribution
Common in the Mediterranean Sea and the eastern Atlantic Ocean, on rocky seabeds rich in algae or on Posidonia oceanica up to 100 meters.
Related species
It can be confused with Marthasterias glacialis.
https://it.wikipedia.org/wiki/Coscinasterias_tenuispina Gallery
