Sand sea stars (Astropecten) on the Shores of Singapore

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Phylum Echinodermata > Class Stelleroida > Subclass Asteroidea

Sand sea stars
Astropecten sp.
Family Astropectenidae
updated Oct 08

Where seen? These fast moving sea stars are commonly encountered on our Northern shores. In sandy or silty shores. They usually remain buried in the sand during the day and emerge to forage at sunset. But they are sometimes seen foraging over the ground on a cool morning or late afternoon.

Features: Diameter with arms 5-10cm. Arms long and tapered. There are particularly long stout flat spines along the sides of their arms. These spines are harmless (not toxic) and probably help them to burrow more quickly into the sand. These spines resemble the teeth of a comb and members of this family are sometimes called Comb sea stars.

Sand stars can move fast, often 'racing' across the sandy bottom of a pool. Their tube feet are modified for a more powerful downward thrust and end in points instead of suckers. These probably allow them to get a grip on soft sediments and burrow more quickly. They can also rapidly burrow into the sand as Mei Lin's video clip below shows.

There appears to be at least two different kinds of sand stars on our shores: the Plain sand star and Painted sand star, possibly more. On this website they are grouped on two different pages for convenience of display.

Astropecten species are identified by the arrangement of the spines along their arms.

What do they eat? These small sea stars are carnivores! They hunt clams and snails, but also eat any small creatures that are buried in the sand. They find buried prey by the substances they release.

These sea stars don't push their stomachs out of their mouths. Instead, they swallow their prey whole. It may take several days to digest their prey. They spit out any indigestible bits such as the shells.

Sometimes, many tiny white snails are found on the upperside of a sand sea star. These are parasitic snails (Family Eulimidae).