ECC Emerald Galaxea

Quick facts

Handling caution: Sweeper tentacles can sting skin and irritate other corals; handle with gloves

Identity

Also known as

Galaxy Coral; Star Coral; Crown Coral

Synonyms

Galaxea fascicularis

Environment

Saltwater

Native to

Indo-Pacific

Habitat

Reef flats and slopes with moderate to strong water movement, often forming large mounding colonies in shallow to mid-depth reef zones

Sourcing

Both

Conservation

Not Evaluated

Care

Care level

Easy

Coral type

LPS

Temperament

Aggressive

Growth form

Massive

Adult size

1 – 12 in (2.5 – 30 cm)

Spread

12 in (30 cm)

Growth rate

Moderate

Placement

Low, Sand bed

Water

Temperature

76 – 80 °F (24 – 27 °C)

pH

8.1 – 8.4

dKH

8 – 12 dKH

Salinity

1.024 – 1.026 SG

PAR

75 – 150 PAR

Flow

Moderate

Light

Medium

Reef care

Nutrient preference

Medium

Alk/Ca uptake

Medium

Target feeding

Beneficial

Give it room

10 in (25 cm)

Colors

Green

Feeding & breeding

Diet

Photosynthetic

Foods

Frozen, Coral food, Zooplankton

Propagation

Fragging

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Care guide

Overview

Sweeper tentacles extend several inches after dark, probing for competing tissue and stinging any coral within reach. Green corallites retract into pale, star-tipped points by day, then flesh out under low to medium light and steady flow. Generous spacing from tankmates is essential given its aggressive temperament.

Care

Galaxea is a hardy large polyp stony coral that grows in mounding colonies of individual corallites, each tipped with a pale, star-like point when the polyps retract. It adapts to a range of lighting from moderate to fairly strong but should be introduced gradually since sudden intense exposure can cause bleaching or tissue recession. Moderate to fairly brisk, varied flow keeps detritus from settling between the corallites without blasting the tissue directly, and stable calcium, alkalinity and magnesium levels support steady skeletal growth.

Placement & acclimation

Acclimate new colonies to light gradually over one to two weeks, starting in a lower-light position and moving up if needed, since overexposure causes more damage than starting too dim. Mount frags or colonies on rock rubble or the sand bed with adequate open space around them so the sweeper tentacles cannot reach neighboring corals. Base rock or a stable substrate works well since Galaxea does not require a specific attachment method.

Feeding

Most of its energy comes from photosynthetic zooxanthellae, but supplemental feeding of small meaty foods such as mysis, brine shrimp or coral-specific zooplankton blends encourages fuller polyp extension and faster growth. Feeding once or twice a week during lights-out or low-flow periods, when the polyps are extended, gives the best results. Target feeding with a pipette or turkey baster reduces waste in the water column and directs food where the coral can capture it.

Neighbors

Galaxea is one of the more aggressive LPS corals kept in reef tanks, capable of extending sweeper tentacles several inches, sometimes reported over a foot, to sting neighboring corals competing for space. Leave generous clearance of at least six to twelve inches from any other coral, more for slow-growing or high-value specimens, and reassess spacing as the colony expands. It is best placed where it will not be brushed by other coral branches or where currents could carry its tentacles into contact with tankmates.

Fragging

Colonies can be fragged by cutting between corallites with a bandsaw, rotary tool, or bone cutters, ideally leaving several polyps per frag for reliable healing. Fresh cuts should be placed in low flow and moderate light until tissue recovers over the cut edges, typically within one to two weeks. Frags are generally hardy and recover well once past the initial healing period.

Pests & problems

Direct, unbroken flow aimed at one side of the colony can cause localized tissue recession, so flow should be varied rather than constant and laminar. Sudden increases in light intensity after acquisition or relocation within the tank can trigger paling or bleaching, so acclimate gradually over one to two weeks. Watch for brown jelly infections or tissue necrosis following physical damage from shipping or fragging, and isolate affected colonies promptly if lesions appear.

Sources

1. ORA Metallic Green Galaxea Coral - Bulk Reef Supply
2. Metallic Green Galaxea – Tank Facts
3. Galaxea Coral Care - Tidal Gardens
4. The best sales on Metallic Green Galaxea - Galaxea sp. - aquariumopt.com

Varieties in the catalog

ORA Metallic Green Galaxea Coral

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