The blue spiny starfish is a small sea star with a span generally measuring only a few inches, with a maximum size of around 4 inches.

The blue spiny starfish is an unusual sea star in many respects ! First, the number of arms varies from 5 to 10, with an average of 7 or 8 arms. In addition, the length of each arm is highly variable. As a result, the blue spiny starfish is far from being a symmetrical star.

As its name suggests, the surface of the blue spiny starfish's body and arms is covered with spines. Its coloration is highly variable and far from uniform.

The blue spiny starfish is widely distributed throughout the Atlantic ocean, from the coast of North Carolina in the north to the city of Santos in Brazil in the south. It is also found along the French Atlantic and Mediterranean coasts, as well as around the Canary islands and the Azores.

The blue spiny starfish is found from the surface to depths of more than 328 feet. It inhabits rocky seabeds, coralligenous habitats, crevices and rocky overhangs, where it shelters from sunlight during the day.

The blue spiny starfish feeds on a variety of small marine invertebrates, such as mollusks.

The blue spiny starfish reproduces sexually by producing and releasing gametes into seawater, but it can also reproduce asexually by splitting its body into two or three pieces and then regenerating.

This mechanism, in which part of the blue spiny starfish's body splits off, can occur when environmental conditions become unfavorable, such as an unusually high seawater temperature or stress during low tide.

The blue spiny starfish is a sea star of tropical origin that was accidentally introduced into the Mediterranean Sea.

Despite its spiny appearance, the blue spiny starfish can be distinguished from the spiny starfish by its smaller size and its greater number of arms, which are also irregular in length !