About Astropecten bispinosus (Otto, 1823)
Astropecten bispinosus (Otto, 1823) is a species of sea star. This sea star has very narrow, high superomarginal plates. A bare area is visible on the vertical face of these plates, along the lateral side of arms between inferomarginal spines and superomarginal spines. Every superomarginal plate has one very long, sharp, clean conical spine; this spine is usually white, but sometimes yellow or orange. The superomarginal spine always sits on the top internal edge of its plate, so there is no bare area on the top of superomarginal plates. The maximum recorded number of superomarginal plates per arm is 77; the number normally ranges between 40 and 60, depending on the size of the starfish. The pair of superomarginal spines located between the arms is often longer than the other spines. Its inferomarginal spines are long, flat, not pointed, and are usually held parallel and well-separated from one another. This Astropecten species has a distinct body shape: it has a very small disc and very long, thin arms. The aboral side is uniformly colored, and may be dark green, dark brown, or rarely light brown-pink. The oral side is light colored, usually white, but can also be yellow or orange. This is a fairly large sea star that can reach approximately 21 centimeters in diameter. This species can be distinguished by its characteristic body shape, high number of superomarginal plates, bare area on the vertical face of superomarginal plates, conical superomarginal spines, and its coloration. It may be confused with the related species Astropecten platyacanthus. Starfishes in the genus Astropecten live on mobile seabeds, which can be sandy, muddy, or gravel. Members of the genus stay largely buried under sediment during the day. In late afternoon and at night, they emerge to hunt, with bivalve molluscs as their preferred prey. This species lives exclusively in the Mediterranean Sea. It prefers sandy seabeds near meadows of Cymodocea nodosa, and occurs at depths between 2 and 100 meters. It is active and easiest to find in late afternoon, but can occasionally be found during the day or night.
