Serpent Star, Ophiura ophiura

The serpent star (Ophiura ophiura) is a species of brittle star that is classified within the Ophiuridae family. It can be found along northwestern coasts of Europe with a range that includes the waters around Sweden, Norway, Madeira, and the Mediterranean Sea. It prefers a habitat in sandy areas at depths of up to 656 feet. This species is typically abundant throughout its range, occurring at a rate of twenty individuals per ten square feet.

The serpent star is small, with a disk that reaches a diameter of 1.5 inches and five long arms that reach an average length of 6 inches. It is typically reddish brown in color with a mottled appearance and a pale underbelly. The upper and under sides of this species hold calcareous plates, while the arms are attached to the body with smaller plates that allow the sea star better movement. This species is active, sometimes burrowing into the sand, and can often be seen swimming in a jerking manner. Like some species of starfish, this brittle star is able to detach limbs and escape danger, later growing the lost arm back.

The serpent star is both a filter feeder and a bottom feeder, consuming detritus and small creatures. The breeding season of this species occurs in the summer months after which fertilized eggs hatch into larvae and later float to the sea floor, developing into young brittle stars. Studies have shown that individuals that have been accidentally caught in fishing trawls have a low rate of survival, even when returned to the sea immediately. Many species feed on these brittle stars while they slowly float to the sea floor, and scavenge them when they reach the floor, including sea birds and crabs.

Image Caption: Ophiura (sp ?), on the sand shore of Oye-Plage (near natural reserve), north of France. Credit: Lamiot/Wikipedia (CC BY 3.0)