Common name
Acan lord
Scientific name
Micromussa lordhowensis
Category
Coral
Group
Large-polyp stony corals
Environment
Marine reef aquarium
Origin
Broad Indo-Pacific distribution; shallow reef environments, especially subtropical localities
Care level
Intermediate
Adult size
Colony spread is open-ended; individual fleshy corallites are commonly several centimetres across, so reserve room for continuing colony expansion.
Expected lifespan
Potentially decades under stable conditions; colony age is open-ended because living fragments can continue the same genet, so a fixed aquarium maximum is not defensible.
Minimum housing
At least 100 L with room for colony expansion and aggression clearance
Temperature
24–27 °C
pH
8.0–8.4
Hardness / minerals
Alkalinity 7–11 dKH; calcium 380–450 mg/L; magnesium 1,250–1,400 mg/L
Salinity
33–36 ppt; specific gravity about 1.024–1.027
Lighting
About 50–150 PAR after gradual acclimation
Placement / zone
Lower to middle reef or a stable sand bed where tissue cannot abrade
Filtration
Use mature reef biological filtration with skimming and removable mechanical capture. Maintain measurable balanced nutrients, prevent detritus lodging between polyps and size export for the growing colony and any supplemental feeding.
Aeration
Maintain strong whole-system gas exchange through surface movement, overflow and skimming while using broad indirect flow around the colony. Avoid direct tissue-blasting jets and stagnant pockets.
Maintenance
Check temperature, salinity and alkalinity frequently; trend calcium, magnesium, nitrate and phosphate; remove settled detritus; inspect tissue, skeleton, mount and neighbours after lights out; and expand clearance as the colony grows.

Identity and search names

Accepted species name Micromussa lordhowensis. Acanthastrea lordhowensis is an older superseded combination. Uniform-coloured colonies may be confused with Micromussa amakusensis.

Search names: Micromussa lord, starry cup coral, Acanthastrea lordhowensis

Environment and housing

Stable lower or middle placement with indirect flow, moderate light and enough clearance for full tissue inflation

Social structure: Sessile colonial coral

Feeding and nutrition

Feeding ecology: Photosynthesis plus captured planktonic and small meaty foods

Feeding routine: Optional targeted feeding once or twice weekly if accepted

Breeding, reproduction or spread

Sexual spawning in nature; aquarium propagation by careful fragmentation of established healthy colonies

Parental care: None

Detailed care and app-ready planning

Identity scope
Accepted species name Micromussa lordhowensis. Acanthastrea lordhowensis is an older superseded combination. Uniform-coloured colonies may be confused with Micromussa amakusensis.
Adult size and space
Reliable maximum colony size is unknown. Begin with at least 100 L and reserve room for open-ended growth plus at least 10–15 cm of aggression clearance.
Colony size and space
Reliable maximum colony size is unknown. Begin with at least 100 L and reserve room for open-ended growth plus at least 10–15 cm of aggression clearance.
Social structure
Sessile colonial animal. The colony expands by polyp growth and must be managed as one growing territorial unit rather than as an isolated frag.
Aggression and spacing
Moderate contact aggression. Inflated polyps can sting neighbours, so prevent tissue contact and reassess spacing as the colony grows.
Swimming zone or placement
Lower to middle reef or stable sand where fleshy tissue cannot rub against sharp rock.
Placement zone
Lower to middle reef or stable sand where fleshy tissue cannot rub against sharp rock.
Feeding ecology
Photosynthetic with the ability to capture small planktonic and meaty foods.
Feeding plan
Offer small food only when polyps respond, usually once or twice weekly at most. Prevent uneaten food lodging between polyps.
Water stability
Maintain 24–27 °C, pH 8.0–8.4, salinity 33–36 ppt, alkalinity 7–11 dKH, calcium 380–450 mg/L and magnesium 1,250–1,400 mg/L with minimal daily swing.
Habitat structure
Use secure support, low to moderate broad flow and gradual acclimation to about 50–150 PAR. Keep sediment from collecting around tissue margins.
Compatibility plan
Provide at least 10–15 cm from other corals, prevent abrasion and avoid direct flow blasting or shading.
Breeding or reproduction plan
Fragment only healthy established colonies with clean tools, stable recovery conditions and correct retained identity.
Propagation plan
Fragment only healthy established colonies with clean tools, stable recovery conditions and correct retained identity.
Quarantine
Inspect tissue folds, skeleton and mount for eggs, flatworms, nudibranchs, algae and wounds in a separate stable coral system.
Quarantine and pest inspection
Inspect tissue folds, skeleton and mount for eggs, flatworms, nudibranchs, algae and wounds in a separate stable coral system.
Welfare checks
Check inflation, feeding response, colour, exposed skeleton, abrasion, sediment and progressive recession.
Biosecurity and release
Use documented legal provenance. Verify BICON, Live Import List, CITES and state rules. Never release coral, fragments, pests or aquarium water.
Biosecurity, sourcing and release
Use documented legal provenance. Verify BICON, Live Import List, CITES and state rules. Never release coral, fragments, pests or aquarium water.
Main risk
Outdated naming and confusion with similar Micromussa can undermine care and provenance.
Adult projected load
As colony surface area increases, calcification demand, night-time respiration, space use, detritus interception and optional feeding load all rise. Plan dosing, gas exchange, nutrient export and physical access for the mature colony rather than the purchased fragment.
Filtration
Use mature reef biological filtration with skimming and removable mechanical capture. Maintain measurable balanced nutrients, prevent detritus lodging between polyps and size export for the growing colony and any supplemental feeding.
Aeration
Maintain strong whole-system gas exchange through surface movement, overflow and skimming while using broad indirect flow around the colony. Avoid direct tissue-blasting jets and stagnant pockets.
Maintenance
Check temperature, salinity and alkalinity frequently; trend calcium, magnesium, nitrate and phosphate; remove settled detritus; inspect tissue, skeleton, mount and neighbours after lights out; and expand clearance as the colony grows.
Overridable warnings
Non-overridable: do not ignore progressive tissue recession, bleaching, exposed skeleton, pest evidence or direct coral contact. A knowledgeable user may use different light, flow, spacing or dosing methods only after gradual acclimation and documented stability show that the colony is not being damaged.

Compatibility, welfare and risk

Compatibility: Allow at least 10–15 cm from neighbouring corals and prevent direct tissue contact

Welfare: Deflation, recession, exposed skeleton, bleaching or repeated tissue abrasion require investigation of water stability, pests, sediment and placement

Main warning: The accepted name is Micromussa lordhowensis; old Acanthastrea naming and confusion with M. amakusensis remain common

Biosecurity and release

Use legally sourced stock with traceable provenance. Check BICON, Live Import List and CITES requirements. Never release coral or aquarium water.

Sources