Spiny Starfish

Description:

This was a large and quite unusual starfish, roughly about 30 to 40cm in diameter, with robust, rounded and rigid arms. I was unable to count arms, as both times I spotted it, it was well hidden under the rocks - however, the literature mention 5 well-differentiated arms, armed with large thick spines. Colours vary a lot, but this one (or these two) were mainly green-grey above, and rusty-pinkish below.

Habitat:

Here photographed in Bay of Cavtat (Dubrovnik riviera), on rocky bottoms in shallow waters near the shoreline. Rocks here are reaching the surface, providing many hiding places, slopping down to 10m gradually. The sea bottom here is rocky, creating many crevasses and tunnels, and rocks are abundantly covered in algae. In those deeper waters, there are some large colonies of sea grass settled on patches of sand.

Notes:

Spiny Starfish has a reputation of being the most voracious predator of Adriatic sea. It feeds mainly on molluscs (oysters, mussels, scallops, etc.), whose shells it is able to open thanks to the strength of its arms. After forcing prey to open up, the starfish then unleashes its stomach inside the mollusc, and digest it externally.