Galaxaura

Galaxaura · also called Tubular Thicket, Pink Succulent Thicket, Bramble Thicket, Tricleocarpa fragilis

Galaxaura is a lightly calcified red macroalgae that grows into rounded, reddish-pink thickets of compact or stout branches. It draws down calcium and alkalinity. One wild species, G. filamentosa, damaged corals on contact in field trials, so keep these plants off corals. Hobby opinion on it is mixed. Pink Succulent Thicket is Tricleocarpa fragilis, formerly Galaxaura oblongata, a close relative kept on this page.

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Quick facts

Category	Marine & Algae
Family	Galaxauraceae
Native origin	Warm-temperate to tropical seas worldwide
Care difficulty	Intermediate
Light	Bright indirect
Pet toxicity	Toxicity unknown

Light

Wants bright reef lighting to support its lightly calcified branches. A well-lit spot on the rockwork or in a macroalgae tank suits it better than a shaded ledge. Keep intensity steady and avoid sudden jumps, since reports of long-term success with this genus are mixed.

Water

Standard reef parameters: 23-27 C (74-80 F), salinity ~1.025 SG, pH 8.1-8.4. Because it calcifies, it needs well-maintained calcium (~400-450 ppm), alkalinity (8-11 dKH) and magnesium (~1300 ppm), and it competes with corals for them. Test more often if the thicket is large.

Soil & potting

Grows on hard surfaces rather than in sand. Tie a ball or branch cluster to rock or rubble with line, or wedge it into a crevice. Site it so the branches cannot rest against corals. The stiff, wiry branches hold their shape, so the plant needs no support once fixed in place.

Environment — humidity, temperature, placement

Moderate to strong flow keeps detritus from building up in the dense branches, which one manual warns it collects. Use a display or macroalgae tank at standard reef temperature, 23-27 C (74-80 F). Bramble Thicket stays very small, reaching only a couple of inches.

Propagation

Growth is slow. Hobby reports describe propagation by fragmentation, and spores may also play a part. Trim a small branch and tie it to rubble. Pink Succulent Thicket (Tricleocarpa fragilis) is somewhat fragile when moved. One aquarium manual calls the genus invasive and advises removing it, so watch for spread.

Toxicity detail

No source covers cats or dogs, so the rating stays unknown. G. filamentosa damaged corals in field trials, and competition with a coral made it nearly twice as damaging, so keep all Galaxaura from resting against corals. Fish rarely eat it, since it is unpalatable and calcified. Harm to fish or shrimp is not documented.

Varieties & cultivars

Natural forms are the wild species; cultivars are selectively-bred colour or variegation forms of the same plant.

Natural forms3

Tubular Thicket

Galaxaura rugosa. A lightly calcified, reddish-pink alga that grows into a ball of compact branches. It is the most familiar Galaxaura in the hobby.

A related species, G. filamentosa, bleached corals on contact in field trials, so keep it from resting against them.

Pink Succulent Thicket

Tricleocarpa fragilis (formerly Galaxaura oblongata). A reddish-pink close relative of Galaxaura, kept on this page, that forms a ball of thick, upright branches, stouter than the compact G. rugosa. It is somewhat fragile when moved.

A related species, G. filamentosa, bleached corals on contact in field trials, so keep it from resting against them.

Bramble Thicket

Galaxaura sp. A very small, branching Galaxaura in reddish pink, reaching only a couple of inches. Fine filaments along its thallus give a fuzzy look, and it is rarely kept.

A related species, G. filamentosa, bleached corals on contact in field trials, so keep it from resting against them.

Quick facts

Light

Water

Soil & potting

Environment — humidity, temperature, placement

Propagation

Toxicity detail

Varieties & cultivars

Natural forms3

Sources