Common starfish Common starfish The common starfish or common sea star ("Asterias rubens") is the most common and familiar starfish in the north-east Atlantic. Belonging to the family Asteriidae, it has five arms and usually grows to between 10–30 cm across, although larger specimens (up to 52 cm across) are known. The common starfish is usually orange or brown, and sometimes violet; deep-water specimens are pale. The common starfish is to be found on rocky and gravelly substrates where it feeds on molluscs and other benthic invertebrates. The common starfish normally has five arms, broad at their base and gradually tapering to
Stichaster striatus these were sessile organisms. It was not found to engage in cannibalism of its own species or to feed on other species of starfish. Many individuals were found to have missing or regenerating arms. This is likely the result of attacks by the dominant predatory starfish in the region "Meyenaster gelatinosus" and "Luidia magellanica". Starfish with missing arms are likely to have a certain minimum size; this is because, if they are too small, they are entirely devoured by the predator which attacked them. Juvenile "S. striatus" are found among the holdfasts of the kelp "Lessonia nigrescens" or hiding in