Linckia Sea Star, Blue EXPERT ONLY

Quick facts

Identity

Also known as

Comet Sea Star; Blue Sea Star; Blue Starfish

Synonyms

Ophidiaster laevigatus

Environment

Saltwater

Native to

Indo-Pacific, Red Sea, East Africa, Hawaii, French Polynesia, southern Japan

Habitat

Shallow reef flats, lagoons, rubble zones, and seagrass beds on sunny upper reef areas, usually less than 20 m deep

Sourcing

Wild-caught

Conservation

Not Evaluated

Care

Care level

Expert Only

Temperament

Peaceful

Adult size

2 – 12 in (5.1 – 30 cm)

Lifespan

2 – 5 yrs

Min tank

100 gal (379 L)

Growth rate

Slow

Placement

Bottom, Rock & glass

Water

Temperature

72 – 78 °F (22 – 26 °C)

pH

8.1 – 8.4

dKH

8 – 12 dKH

Salinity

1.023 – 1.025 SG

Flow

Low-Moderate

Behavior & compatibility

Social

Solitary

Aggression to own kind

Low

Active

Daytime

Reef safe

Yes

Invert safe

Yes

Shrimp safe

Yes

Clean-up role

Algae, Biofilm, Detritus

Population boom risk

Low

Feeding & breeding

Diet

Omnivore

Foods

Algae, Biofilm, Frozen

Breeding type

Broadcast spawner

Breeding difficulty

Not bred in captivity

Sexing

Sexes are externally indistinguishable; can only be determined by examining gonads or observing spawning behavior

Target feeding

Beneficial

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Care guide

Overview

Creeps in a slow, continuous grazing motion across live rock and rubble, rasping at the biofilm coating hard surfaces. Its five arms carry a deep blue body, occasionally marked with red or purple flecks, and it needs an established reef with years of undisturbed biofilm growth to avoid slow starvation. Suited only to seasoned reefkeepers able to hold stable parameters and a copper-free system.

Care

This sea star needs a large, well-established reef system with years of undisturbed rock surfaces that have built up a natural biofilm layer, since that film makes up the bulk of its diet in captivity. It creeps slowly across live rock and rubble grazing as it goes, and does best with plenty of rockwork and open sandy or rubble areas for foraging. Sudden shifts in salinity, pH, or dissolved oxygen are poorly tolerated, and copper-based medications used anywhere in the system will kill it, so it should never share water with a hospital tank being treated with copper.

Feeding

In the wild it grazes almost continuously on biofilm and organic films coating rock and rubble, along with detritus and possibly some algae. Captive feeding is notoriously unreliable, and many specimens slowly starve over six to twelve months even in reasonable setups because aquarists cannot replicate the constant grazing surface available on a natural reef. Offering small pieces of clam, shrimp, or other meaty foods placed directly under the animal can supplement its diet, but this only partly offsets the lack of biofilm in most home systems.

Tank mates

Generally peaceful and solitary, tolerating other sea stars and calm reef fish without issue, and it will not harm corals or sessile invertebrates. Avoid housing it with pufferfish or other invertebrate-picking fish, which may nip at its arms or tube feet. It can be kept with other Linckia species but multiple individuals compete for the same limited biofilm supply, so most keepers stick to just one per tank.

Breeding

Spawning occurs seasonally, typically between May and August in the wild, with males and females releasing gametes freely into the water column after gathering in groups to improve fertilization odds. Larvae drift in the plankton for about a month before settling and metamorphosing into juveniles, a process essentially impossible to replicate in a home aquarium. Asexual reproduction by fission, where a detached arm regenerates into a new individual, occurs far more readily in the wild than in captivity.

Health

Watch the underside of the arms for Thyca crystallina, a small parasitic snail that attaches permanently and feeds on the star's fluids, leaving a visible scar at the attachment site. Stress from starvation, cramped quarters, or unstable water parameters commonly triggers a bacterial "melting" that turns patches of an arm white and soft, which is usually fatal once it begins. Thin, shrunken arms are an early warning sign of chronic starvation and should prompt closer monitoring of the animal's condition.

Sources

1. Linckia Sea Star, Blue: Saltwater Aquarium Starfish for Marine Reef Aquariums - LiveAquaria
2. Linckia laevigata | INFORMATION | Animal Diversity Web
3. Blue linckia star care: tank size, temperature and tankmates · TankBud
4. Section: Starfish/Sea Stars: Species: Linckia laevigata (Blue Star, Blue Linckia)

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