Smooth Sea Star

Overview

The Smooth Sea Star (Hacelia attenuata) is a distinctive echinoderm native to the Mediterranean Sea and parts of the temperate Atlantic, including the Azores and Canary Islands. It is a solitary, bottom-dwelling species typically found in rocky environments where it leads a largely sedentary life.

Distribution & habitat

This species inhabits rocky and coralligenous seabeds, often favoring shaded areas such as overhangs and caves. While it can be found across a wide depth range, it is most commonly encountered between 10 and 50 meters, though it may occur from the shallows down to approximately 190 meters.

Appearance

Characterized by a small central disc and five long, conical arms that taper to a point, this sea star can reach a diameter of 20 to 30 cm. Its surface is smooth and satin-like to the touch, featuring regular rows of limestone plates and longitudinal depressions that often appear as darker, small craters. The coloration is variable, ranging from pale yellow and orange to bright red, with a lighter-colored underside.

Feeding

Hacelia attenuata is a specialized carnivore that feeds primarily on sponges. It is considered a macrophage, meaning it consumes relatively large food particles relative to its size.

Reproduction

This species is oviparous, with sexual reproduction typically occurring between June and September. It produces larvae that undergo a prolonged planktonic phase before settling.