Not furry either, still lovely.

Sand Sifting Starfish

Astropecten polyacanthus

Also called Sand sifting sea star, Comb sea star

SpeciesShort profile

From Indo-Pacific, from the Red Sea and Zanzibar east to Hawaii, and from Japan south to Australia and New Zealand; lives on silty sand in harbours and estuaries down to about 185 m.1

At a glance the quick version

Lengthup to 20 cm1 2

Sizemedium

Arm spread up to about 20 cm (8 inches); individual arms up to 9 cm.

Keeps the sand bed stirred

Fascinating burrowing behaviour

Peaceful towards fish

2 1

Looks how to spot one

Spiny five-armed star

A flat five-armed sea star whose arms are edged with a fringe of stiff spines. Its tube feet end in points rather than suckers, ideal for digging through sand.1 2

ColoursDark purplish or brown upper sideOrange undersideCream, grey or beige banding1 2

Personality what they are like

A calm, mostly nocturnal star that spends much of the day buried in the sand and moves slowly and steadily when it forages.1 2

Daily activity how busy a day looks

Burrows through the sand bed searching for food, mostly at night.1 2

Grooming and care the hands-on bits

Drip acclimate, never lift it into open air, keep water stable and avoid copper-based treatments.2

Home where they are happiest

A mature marine tank with several inches of deep sand to burrow in. Stable, fully marine water at about 22-26 C, pH 8.1-8.4, salinity (specific gravity) 1.023-1.025 and dKH 8-12.2

Food basics what goes in the bowl

A carnivore and scavenger that eats detritus, small molluscs and other small invertebrates; in a home tank it should be offered a varied meaty diet so it does not run short of food.1 2

Company who they like around

Peaceful with fish; may eat small invertebrates living in the sand. Keep away from puffers.2

The story where it all began

Muller and Troschel described this sea star in 1842. It is widespread across the warm Indo-Pacific and is kept by reef aquarists for its habit of working through the sand bed.1

Fun facts for the dinner table

1
Its tube feet are pointed instead of having suckers, which helps it dig.1
2
It swallows small clams and snails whole.1
3
It sometimes swallows pebbles to feed on the film of tiny life growing on them.1
4
It has been found as deep as about 185 m.1

Recognised by the official bits

Taxonomy (via Wikipedia): Described by Muller and Troschel in 1842 (family Astropectinidae).1

The care rhythm Furry Diary remembers it for you

A typical home-care rhythm for a Sand Sifting Starfish. It is our own starting plan, not a vet's advice, and you can change every line in the app.

FeedingDepends on species, many feed from the light and the watervaries
Salinity checkevery week
Water testevery week
Top-upTop up evaporation with fresh RO water, not salt waterevery day
Water changeAbout 10 to 20% of the waterevery 2 weeks
Light checkevery month

Start a free diary

Chocolate Chip Starfish

Blue Linckia Starfish

our little thank-you jar

Like what we are building? Buy Archy a bone.

All of this is free for everyone, with a source on every fact, and it will never show ads. It was a big job to build, so if it helped you, buy Archy a bone. Any amount is lovely, and no is a perfectly fine answer too.

Archy is our Australian Cattle Dog and chief taste tester. Tips go to 4V3D OÜ, the small family studio behind Furry Diary.

Buy Archy a bone

Where this comes from

Every breed page shows where each fact comes from. If we got something wrong, sorry, we are pet people, not a science magazine. Tell us at support@furrydiary.app and we will fix it.

Astropecten polyacanthus (Wikipedia) en.wikipedia.orgused for names, range, size, colours, body, behaviour, diet, taxonomy, fun facts
Sand Sifting Sea Star (LiveAquaria) liveaquaria.comused for size, colours, temperament, water parameters, care, diet in captivity

Checked 2026-09-30. Text is written in our own words from these sources.