pest debate · saltwater tank

Asterina Starfish

Asterina starfish are tiny (5-15mm) starfish that hitchhike in on rock and reproduce by fission. Some species eat coral; most are harmless detritus-eaters.

Reviewed by Fast Aquatics husbandry team · Updated May 2026
Severity: Variable - most are harmless, some species eat coral

Symptoms

What causes it

Hitchhiked in on uncured rock or live coral.

Treatment options

Always treat in a separate quarantine tank.

Harlequin shrimp. Harlequin shrimp eat ONLY starfish. One pair will clear an Asterina population in 2-4 weeks. After cleanup, you must continue providing starfish (frozen or trade-acquired).
Manual removal. Pluck visible Asterina during water changes if numbers are low.

Prevention

Dip new pieces; cure rock for 4-6 weeks before placement.

Frequently asked questions

What does Asterina Starfish look like?

Small 5-15mm starfish on rock or glass. Multiplying rapidly. Sometimes seen on coral.

What causes Asterina Starfish?

Hitchhiked in on uncured rock or live coral.

How is Asterina Starfish treated?

Harlequin shrimp: Harlequin shrimp eat ONLY starfish. One pair will clear an Asterina population in 2-4 weeks. After cleanup, you must continue providing starfish (frozen or trade-acquired).

Can Asterina Starfish be prevented?

Dip new pieces; cure rock for 4-6 weeks before placement.

How fatal is Asterina Starfish?

Variable - most are harmless, some species eat coral

Related

Browse the full disease database for 45 aquarium conditions with treatment protocols, or check the care library for prevention-focused husbandry guides. Use our symptom matcher to rank likely diseases from observed signs, the water parameter checker to diagnose related water-quality issues, or the QT timeline calculator to plan a treatment schedule.