Care guide · Marine · corals

Pulsing Xenia

Xenia

Genus level

Xenia umbellata — an example within this genus guide; traded forms may differ. Photo: Diego Delso · Source · CC BY-SA 4.0Resized and compressed; no cropping or colour changes.

Xenia is a genus of soft corals, many traded forms of which have rhythmically opening and closing polyps. The movement is fascinating, but not every trade animal pulses continuously or identically. This guide therefore treats Xenia at genus level rather than applying research on one named species to every form. A small colony can expand rapidly in favourable conditions. Select a manageable position beforehand, preferably a separate rock, instead of starting it among slow-growing corals. Xenia needs a stable marine aquarium, suitable lighting and water exchange. It is neither a tool that automatically repairs poor water quality nor a reliable living pH meter.

Plan your aquarium →

At a glance

Identification level: Genus level
Coral group: Soft coral
Difficulty: Easy
Growth and pruning: Fast
Temperature: 24–26 °C
Specific gravity (SG at 25 °C): 1.025–1.026 SG
pH: 8.1–8.3
Alkalinity: 8–9 °dKH
Calcium: 400–450 mg/L
Magnesium: 1250–1350 mg/L
Light requirement: Moderate
Flow requirement: Low to moderate, Moderate
Position: Low, Middle
Aggression: Semi-aggressive
Supplementary feeding: Optional

Water values are reef-care guidance, not proven species limits. PAR describes only the stated culture experience; stability and gradual acclimation remain important.

About this coral

Polyps have the feathered tentacles characteristic of octocorals and stand on soft tissue without a massive calcareous skeleton. Trade names sometimes include related xeniids. Identification requires more than pumping movement alone. The photo illustrates Xenia without identifying every traded specimen as that exact species. Pulsation, colour and branching may change with conditions; retain uncertainty when a supplier cannot provide reliable identification.

Natural habitat

Xenia species are known from tropical Indo-Pacific and Red Sea environments. Research on Xenia umbellata shows that conditions and nutrition are more complex than a fully photosynthetic label suggests. That study species does not represent the whole genus. Provide stable conditions, light and exchange around polyps. Prevent escape into nature: living material and used substrate must never enter natural waters.

Aquarium and layout

A separate rock makes expansion easier to follow and contain. Do not allow unnoticed bridges to the main rockwork. Check detached fragments that could attach elsewhere. No fixed minimum volume is supported for the whole genus. Growth and fluctuations can become particularly important in small aquaria. Choose an inspectable site with enough light and without a continually hard pump load.

Water conditions

Stable salinity and temperature remain fundamental. Rapid growth in some nutrient-rich systems does not make accumulating pollution desirable. Record measurements and maintenance and avoid abrupt corrections. Reduced pulsation does not demonstrate iodine deficiency or justify speculative supplements. Calcium and alkalinity management follows whole-reef measured consumption too. Universal hard nitrate and phosphate limits are not established for the genus.

Lighting and acclimation

Use suitable reef lighting and acclimate new colonies gradually. An experimental light reading in X. umbellata research does not prove a minimum, optimum or maximum for all Xenia. It is therefore not displayed as a general PAR range. Observe expansion, growth and tissue condition; pulsation alone is not a light meter. Growing neighbours or the colony itself can change exposure without changing lamp settings.

Water movement

Gentle to moderate indirect movement is a practical starting point, allowing exchange without flattening the polyps. Research within a limited flow range on one species does not justify stagnant water or a hard jet. Pulsation affects local movement but does not replace aquarium circulation. Watch debris and the whole colony. A different pump setting can change visible pulsing without establishing disease.

Feeding

These animals combine symbiont contributions with other nutritional routes. X. umbellata experiments found responses to organic material, not a home recipe for dosing sugar or arbitrary products. A general Xenia profile lacks evidence making targeted feeding mandatory. Large meat pieces are unsuitable. If fine supplementary food is considered, assess actual suitability and water load. Increased pulsing after an addition does not prove a lasting health benefit.

Growth and behaviour

Xenia can occupy new areas quickly under favourable conditions, while growth varies considerably between aquaria. Plan for control rather than a promised rate. Inspect rock edges and carefully manage unwanted expansion before it lodges among sensitive corals. Sudden loss of a large tissue mass can burden the system. Keep the colony manageable; do not treat it as indefinitely expandable filter material.

Aggression and spacing

Overgrowth and space occupation matter more than an invented fixed sweeper distance. Xenia can surround slow neighbours and restrict light or circulation. A narrow bare gap will not maintain itself when tissue reaches new substrate. Preserve a manageable separation between rocks and check it regularly. Even without obvious stinging damage, a pairing can become unsuitable in a crowded small reef.

Keeping with fish

Polyp-nipping fish may injure a colony or keep it closed. A dwarf angelfish is not automatically suitable on the basis of a general reef label. Equally, do not buy a fish as a guaranteed biological solution to unwanted Xenia: that behaviour is unreliable and may affect other corals. Assess the particular fish, colony size and observed behaviour.

Keeping with corals

Keep slow-growing LPS and SPS outside the expansion route. A growing leather coral cap may eventually shade Xenia; Xenia can surround low frags in turn. A separate rock helps but does not remove maintenance. Consider differing local flow needs as well as space. Conditional coexistence means growth can be actively managed, not left to intermingle unchecked.

Other invertebrates

Marine snails may mainly disturb small frag attachments, but a safe assessment still requires a specific species. Crabs, shrimp and starfish have varied diets. Assess actual contact and injury, not a clean-up crew label. Do not introduce animals expecting them to eat only unwanted growth. Unsupported relationships remain unknown; existing freshwater invertebrates are inapplicable.

Propagation and fragging

Moving an already attached piece with its small holder is more manageable than allowing loose tissue through the tank. Have an experienced grower divide material when uncertain and avoid unnecessary basal damage. Protect hands and eyes from mucus and prevent fragments entering pumps or inaccessible rockwork. Never release material into natural waters. Assess a weakened colony before attempting propagation.

Possible problems

Reduced or absent pulsation is not a diagnosis by itself. Also check expansion, growth, mucus and tissue retention. After sudden change, investigate temperature, salinity, pump settings, additions and tankmates. Rapid tissue disintegration requires attention to both the colony and the rest of the reef's water. Do not successively add iodine, food and treatments to restore movement. Record progress and seek experienced help if deterioration continues.

Keeping with other species

Care products

No sufficiently supported match to a specific existing care product has been established for this coral. Follow the feeding and care chapters; an absent product card does not mean feeding or measurements are unnecessary.

Sources & review

This care guide draws on several specialist sources and was last checked on 9 October 2026.

View the sources