Gray Sea Star

luidia clathrata

The Gray Sea Star (Luidia clathrata) is an active and fascinating marine echinoderm native to the warm coastal waters of the western Atlantic. Unlike many of its slow-moving, rock-climbing relatives, this species is highly adapted for a dynamic life on soft, shifting sediments. Lacking the typical suction-cupped tube feet, it features pointed, agile tube feet that allow it to glide smoothly and rapidly across sandy and muddy sea floors, or quickly burrow beneath the surface to hide from predators or ambush prey.

Habitat: Found in shallow coastal waters, typically on soft sandy or muddy sea floors where it can easily burrow.

Appearance

This sea star typically features five long, flattened, tapering arms radiating from a relatively small central disc, reaching an overall diameter of 15 to 30 centimeters. Its coloration ranges from light bluish-gray to creamy gray or light brown, and it is easily recognized by a distinct, dark gray or blackish stripe running down the midline of the upper surface of each arm. The upper body is covered with tiny, table-like structures called paxillae that give it a finely granulated texture, while its underside reveals pale, pointed tube feet.

KingdomAnimaliaPhylumEchinodermataClassAsteroideaOrderPaxillosidaFamilyLuidiidaeGenusLuidia

Photo: Steven JoynerCC BY 4.0 · iNaturalistView original ↗

Gray Sea Star

Interesting facts

It has the impressive ability to swallow small prey items, such as clams, completely whole; it then digests the soft tissues internally and spits the empty, clean shells back out.

The distinct dark line down the middle of its arms is formed by a precise biological alignment of its paxillae—tiny, umbrella-shaped skeletal plates that keep sand off its sensitive skin.

Unlike most sea stars that rely on suction cups to scale hard vertical rocks, the Gray Sea Star features pointed, claw-like tube feet uniquely adapted for scurrying over and tunneling into sand.

Special abilities

Uses its specialized, pointed tube feet to quickly shovel sand aside, allowing it to sink beneath the sediment within seconds to avoid predators or search for food.

Can voluntarily shed an arm when threatened or seized by a predator, later regenerating a complete new arm over several months.

Moves surprisingly fast over soft substrates using coordinated, stilt-like walking motions of its pointed tube feet rather than suction-cup crawling.

Measurements & details

Length: 15+ cm
Weight: 0.05+ kg
Lifespan: 3+ years

Diet & Feeding

Primarily feeds on small, burrowing invertebrates such as bivalves, gastropods, and small crustaceans, which it swallows whole or digests externally.

Age differences: Juveniles feed on organic detritus and microscopic organisms in the sediment, while larger adults target shelled mollusks and active crustaceans.

Primary Foods

Coquina Clams
Dwarf Surfclams
Amphipods
Polychaete Worms

Foraging Method

Foraging

Ecological connections

Hunts

Coquina Clam

Donax variabilis

Preys heavily on this small, burrowing bivalve found in the same sandy littoral zones.

Competitor

Beaded Sea Star

Astropecten articulatus

Competes for sandy benthic space and similar small infaunal invertebrate prey.

Eaten by

Gag Grouper

Mycteroperca microlepis

This predatory fish occasionally feeds on juvenile and adult Gray Sea Stars.

Traits

No trait badges are assigned for this object yet.

Also known as

No aliases listed yet.

Collections

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Safety

Danger

1/5 · Very low

No special safety notes yet.

Frequently Asked Questions

How to identify Gray Sea Star?

Look for fins, arms, tentacles, shells and body symmetry. Underwater light shifts colors, so structure and markings usually matter more than shade. Sea Creature Identifier: upload a photo and compare the visible details.

How long is Gray Sea Star?

15+ cm

How much does Gray Sea Star weigh?

0.05+ kg

How long does Gray Sea Star live?

3+ years

What does Gray Sea Star eat?

Primarily feeds on small, burrowing invertebrates such as bivalves, gastropods, and small crustaceans, which it swallows whole or digests externally.

Where is Gray Sea Star usually found?

Found in shallow coastal waters, typically on soft sandy or muddy sea floors where it can easily burrow.

How does Gray Sea Star hunt?

Foraging