Valonia

Valonia · also called Sailor's Eyeball, Branching Bubble, Bubble Algae, Sea Pearl, Ventricaria ventricosa

Easy to grow and hard to remove. Valonia is a green macroalgae made of large, glassy, bubble-like cells. V. ventricosa, the Sailor's Eyeball, ranks among the biggest single cells known, usually 1 to 4 cm across. Reef keepers know bubble algae as a common hitchhiker and nuisance, so add it only to a tank meant for it.

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Quick facts

Category	Marine & Algae
Family	Valoniaceae
Native origin	Tropical and subtropical seas worldwide
Care difficulty	Beginner
Light	Medium light
Pet toxicity	Toxicity unknown

Light

Grows under ordinary reef lighting and needs nothing special, which helps explain why it turns up so often on live rock. Moderate light is plenty for a display piece. No firm lighting targets are recorded, and light alone is not a recorded means of keeping it under control.

Water

Standard reef parameters: 23-27 C (74-80 F), salinity ~1.025 SG, pH 8.1-8.4. It is undemanding, and hobby advice links outbreaks to excess nutrients, so good skimming and low nitrate and phosphate help limit it. Clean water alone will not clear an established colony without manual removal.

Soil & potting

Attaches to rock at its base rather than growing in sand. Branching forms build clusters on rock and can wedge into crevices. If you keep a Sailor's Eyeball, leave it on its rock and do not pull it free, because a ruptured cell wall can release new cells into the tank.

Environment — humidity, temperature, placement

Comes from tropical and subtropical seas and copes with most reef flow at standard reef temperature, 23-27 C (74-80 F). A macroalgae tank or refugium is the safest home. Inspect new rock and coral bases before they go in, since it often arrives as a hitchhiker.

Propagation

When a bubble wall wears out or ruptures, new cells can be released and spread through the tank. Reports on V. ventricosa vary: some call it slow to spread, others treat it as a pest. Lift bubbles out whole with a baster or siphon, and never pop them in the tank.

Toxicity detail

No toxicity data for tank animals was found, so the rating stays unknown. The risk is overgrowth, since a colony can spread across rock and crowd corals. Emerald crabs often eat it, but they are not fully reef safe and one crab may not be enough. Chemical treatments can also harm live rock.

Varieties & cultivars

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

Natural forms2

Sailor’s Eyeball

Valonia ventricosa. Large, round, glassy spheres that rank among the biggest single-celled organisms on Earth. Usually 1 to 4 cm across, rarely up to about 5 cm.

Treat it as a potential pest: it can multiply on live rock and crowd corals. Keep it only in a tank meant for it, lift bubbles out whole and never pop them.

Branching Bubble

Valonia sp. A Valonia that, as the name suggests, grows in branching, bubble-like clusters. It can spread if left unchecked, like other bubble algae.

Watch its spread and remove any excess before it gets established.