Acanthastrea / Micromussa lordhowensis (“Acan Lord”)

Taxonomy & Identity

Formerly placed in Acanthastrea, Micromussa lordhowensis is the species behind the hobby’s beloved “Acan Lords.” These are fleshy, multi-polyp LPS corals with intense, multi-color patterns and relatively forgiving care requirements.

Natural Habitat & Distribution

M. lordhowensis is found in the Western Pacific, including around Lord Howe Island and nearby regions. It typically inhabits lower reef slopes and protected areas with moderate light and flow, often in slightly turbid water.

Morphology & Growth Forms

Acan Lords form low, encrusting to mound-like colonies composed of many fleshy polyps sharing a common skeleton. Each polyp has a central mouth and thick tissue that can expand significantly. Color patterns are extremely diverse—rings, stripes, and speckles in reds, oranges, greens, blues, and purples are common in aquacultured strains.

Lighting Requirements & Spectrum

• Intensity: Low to moderate
• Target PAR: 50–120

Acan Lords prefer relatively gentle lighting. Too much intensity can cause tissue recession, especially along the edges of polyps, and can wash out colors. They are ideal for sandbeds, lower rockwork, and shaded ledges. Blue-heavy lighting brings out their fluorescence and contrast.

Flow Requirements & Patterns

• Intensity: Low to moderate
• Type: Indirect, oscillating

Flow should gently move the fleshy tissue without causing it to flap or expose skeleton. Direct, high-velocity jets can damage tissue and lead to recession. Slightly higher flow at night helps clear food and waste after feeding.

Nutrient Dynamics & Water Chemistry

Acan Lords thrive in moderate nutrient systems and often look best with a bit of nitrate and phosphate present. Ultra-low nutrient environments can lead to pale colors and slow growth. As always, stability in alkalinity and salinity is crucial.

Feeding Biology & Symbiosis

Acan Lords host zooxanthellae but are also enthusiastic feeders. They extend feeder tentacles, especially at night or when food is present, and readily accept a variety of meaty foods.

• Mysis shrimp and finely chopped seafood
• Small LPS pellets
• Reef blends and fine particulate foods

Target feeding 1–3 times per week can dramatically increase growth, polyp size, and coloration, particularly in lower-nutrient systems.

Common Diseases, Pests & Predators

• Brown jelly infections after physical damage or severe stress.
• Tissue recession from edges due to excessive light or flow.
• Occasional nipping by angelfish, butterflies, or certain wrasses.

Most issues are preventable with stable parameters and careful placement. If brown jelly appears, siphon it off, perform an iodine-based dip if desired, and improve flow and stability.

Compatibility & Placement

Acan Lords are moderately aggressive. Their feeder tentacles can sting nearby corals, especially other LPS, within a short radius. They are best given a bit of space from delicate neighbors but can be grouped with other Acan Lords to form colorful colonies.

• Best zone: Sandbed or lower rockwork with gentle light and flow.
• Give space: 1–3 inches from other species, more from sensitive SPS.

Fragging Techniques

Acan Lords can be fragged by cutting through the skeleton between polyps with a coral saw. Each frag should include at least one healthy polyp, preferably more. Frags heal well under stable conditions and will grow new polyps along the edges over time.

Aquacultured Strains & Trade Names

The hobby is full of named Acan Lord morphs—“Rainbow Acan,” “Ultra Lord,” “Bloodshot,” “Inferno,” and countless others. Most are aquacultured and adapt extremely well to aquarium conditions, making them a staple of modern LPS collections.

Difficulty Rating & Summary

Difficulty: Beginner to Intermediate

Acan Lords are one of the most rewarding LPS corals: vivid color, dramatic feeding response, and manageable care. With low-to-moderate light, gentle flow, stable parameters, and regular feeding, they will thrive and become a centerpiece of your lower reefscape.