Sea urchin reproduction
Also this summer we met some sea urchins all piled in one place. We therefore think we have filmed again the reproduction of Sphaerechinus granularis. Like other echinoderms, sea urchins reproduce in the summer and synchronize by massing together releasing the gametes at the same time, to increase the possibility of fertilization. Riproduzione ricci di mare Sea urchin reproduction intotheblue.it

In this video we see some specimens of Sphaerechinus granularis on a depth of about 50 meters, the thing that intrigued us is not so much the phenomenon that we have already encountered several times, but the fact that we have not found the multitude of specimens that we he would expect to find and that in the surroundings we have observed some dead sea urchins, split as if something had overwhelmed them.
The logical conclusion unfortunately was that of the passage of a trawler passed a few days before that practically devastated the area leaving few specimens that probably escaped the net for a few meters.

Sphaerechinus granularis is a species of sea urchin in the family Toxopneustidae, commonly known as the purple sea urchin. Its range includes the Mediterranean Sea and eastern Atlantic Ocean. In the video we can see it lying on a rock wall at a depth of about 15 meters, covered with algae and detritus. Sphaerechinus granularis Purple sea urchin intotheblue.it

Echinoderm is the common name given to any member of the philum Echinodermata of marine animals. The adults are recognizable by their (usually five-point) radial symmetry and include such well-known animals as sea stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies or “stone lilies”. Echinoderms are found at every ocean depth, from the intertidal zone to the abyssal zone. The phylum contains about 7000 living species, making it the second-largest grouping of deuterostomes (a superphylum), after the chordates (which include the vertebrates, such as bird, fishes, mammals, and reptiles). Echinoderms are also the largest phylum that has no freshwater or terrestrial (land-based) representatives. i
https://en.wikipedia.org/wiki/Sphaerechinus_granularis
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