Cynarina donut coral is one of the most eye-catching fleshy LPS corals in the reef hobby because of its inflated tissue, bright coloration, and dramatic single-polyp appearance. Often called button coral, meat coral, doughnut coral, cat’s eye coral, or tooth coral, Cynarina can become a true centerpiece in a reef tank when it is given the right conditions. This guide explains how to care for Cynarina donut coral in a reef tank, including water quality, lighting, flow, feeding, placement, handling, and the most important warning signs to watch over time.

For many reef keepers, Cynarina is appealing because it combines bold visual impact with a calmer, lower-position look that works beautifully in mixed reefs and LPS-focused tanks. It is also a coral that often responds visibly to its environment, making it easier for hobbyists to spot when something is right or wrong. With proper care, Cynarina can remain inflated, colorful, and healthy for years.

Looking to add a fleshy showpiece coral to your reef tank? Browse our LPS corals for sale and explore healthy corals for your aquarium.

What Is Cynarina Donut Coral?

Cynarina donut coral is a fleshy large polyp stony coral known for its round inflated body and striking patterning. It is often identified by its single large polyp and smooth, fleshy appearance, which makes it very different from many branching or encrusting corals in the reef tank.

Its common names include button coral, meat coral, doughnut coral, cat’s eye coral, and tooth coral. No matter what name hobbyists use, it is widely loved for the same reason: it looks impressive in the aquarium and can become a major focal point when healthy.

Natural Habitat and Why It Matters

Cynarina is naturally found in the tropical Indo-Pacific region, including areas such as the Red Sea. In the wild, it is often associated with outer reef slopes and drop-offs. Understanding that natural environment helps explain why it usually does best in a clean, stable reef system with moderate lighting and moderate flow.

Although these reefs may experience turbulent conditions, Cynarina itself should not be blasted with direct harsh flow in the aquarium. It is better treated as a fleshy display coral that needs comfortable, stable conditions rather than extreme exposure.

Why Cynarina Coral Is So Popular

• It has a large inflated fleshy appearance
• It shows bold color and pattern variation
• It works beautifully as a showpiece coral
• It adds a premium LPS look to the reef tank
• Its expansion can help you judge coral comfort and tank stability

One of the interesting things about Cynarina is how visibly it responds to its environment. A healthy, well-settled specimen often looks inflated and comfortable, while stress usually shows clearly in the tissue.

Water Quality

Maintaining stable water conditions is the most important part of keeping Cynarina healthy. Like many fleshy LPS corals, it does best when the tank is consistent and not prone to repeated swings.

• pH: 8.1-8.4
• Salinity: 1.023-1.025
• Alkalinity: 8-12 dKH
• Calcium: 380-420 ppm
• Magnesium: 1200-1350 ppm

Weekly water changes of about 10-20% can help maintain stability and keep the coral in a healthier environment. Clean, steady water quality usually does more for Cynarina than reactive corrections after problems appear.

If you are working on chemistry stability, read our guide on reef tank water parameters.

Lighting

Cynarina donut coral usually does best under moderate to moderately high lighting. It can handle a stronger reef lighting setup if it is acclimated carefully, but too much intensity too quickly can cause photodamage and tissue stress.

• Recommended PAR: about 100-250
• Moderate to moderately high lighting is usually best
• Gradual acclimation helps prevent bleaching and stress
• Stable lighting is generally better than frequent changes

In many reef tanks, Cynarina performs best when it is not placed in the harshest top-light zone but still receives enough intensity to support color and health.

If you want to understand reef lighting better, read our guide on reef tank lighting.

Flow

Cynarina prefers moderate water flow. Good flow helps keep the coral clean and allows it to interact naturally with the surrounding water, but too much direct current can irritate fleshy tissue and reduce expansion.

• Moderate indirect flow is usually ideal
• Avoid strong direct blasting from powerheads
• Too little flow can allow debris to settle on the coral
• The coral should look full and comfortable, not flattened

The best flow usually keeps the coral clean without making it shrink or stay tightly retracted.

If you want to learn more about circulation, read our guide on water flow and coral health.

Feeding

While Cynarina gets much of its energy from photosynthesis, it also benefits from supplemental feeding. Feeding can help support tissue condition, fullness, and overall health when done carefully.

• Offer small meaty foods such as mysis shrimp or brine shrimp
• Feed once or twice a week as a practical starting point
• Avoid overfeeding because it can hurt water quality
• Watch the coral’s feeding response before increasing frequency

Like most fleshy LPS corals, Cynarina usually responds best to a balanced routine where feeding supports the coral without pushing nutrients too high.

Placement

Cynarina donut coral needs enough space to expand and contract fully without scraping against rocks, glass, or neighboring corals. Placement is especially important because its fleshy tissue can be damaged more easily than hobbyists sometimes expect.

• Give the coral enough open space around it
• Keep it away from aggressive or stinging corals
• Avoid tight placement against the tank glass
• Do not let the underside rub on rough rockwork

Lower to middle tank placement is often a practical starting point for Cynarina, especially on a flat, safe surface where it can sit comfortably without abrasions.

Handling and Removal

Cynarina should be handled with extra care because of its large inflated fleshy tissue. One of the biggest handling mistakes is removing a heavily inflated specimen directly from the water, which can place damaging weight on the polyp.

• Handle the coral gently
• Avoid lifting it out while the tissue is highly inflated
• Let the coral retract somewhat before removal when possible
• Support the specimen carefully during moves

A little extra caution during handling can prevent tears and long-term damage to valuable tissue.

Observation and Monitoring

Regular observation is one of the most important parts of Cynarina care. These corals often show visible early warning signs when something in the environment is wrong.

Watch for:

• Tissue recession
• Discoloration
• Poor inflation
• Unusual behavior or long-term retraction

If any of these signs appear, it is best to review water quality, lighting, flow, and placement before the issue becomes more serious.

Common Cynarina Problems

Tissue Recession

This is often linked to unstable water parameters, poor water quality, rough handling, or ongoing irritation from placement.

Color Loss

Lighting stress, nutrient imbalance, or general system instability can reduce coloration over time.

Poor Expansion

If the coral does not inflate well, common causes include improper flow, nearby aggression, or discomfort with placement.

Physical Abrasion

Cynarina tissue can be damaged by glass, rough rock, or contact with surrounding corals if it does not have enough room.

How to Tell If Cynarina Is Healthy

• The tissue stays full and inflated
• Color remains rich and stable
• The coral responds to feeding
• There is no visible recession or tearing
• The specimen looks comfortable in its placement zone

A healthy Cynarina usually looks fleshy, colorful, and settled. When it remains inflated and stable over time, that usually means the surrounding conditions are working well.

Best Tank Setup for Cynarina Donut Coral

Cynarina usually does best in reef tanks with:

• Stable water chemistry
• Moderate to moderately high lighting
• Moderate indirect flow
• Safe, open placement areas
• Consistent observation and maintenance

It is a strong choice for hobbyists who want a premium fleshy LPS coral that can become a true showpiece in a well-run reef tank.

Related Corals You May Also Like

If you are interested in Cynarina donut coral, you may also want to explore other fleshy LPS corals and related reef tank guides:

• Browse LPS corals for sale
• Acanthophyllia, Cynarina and Indophyllia comparison
• Symphyllia coral care guide
• Trachyphyllia coral guide
• LPS corals overview

Ready to add a fleshy showpiece coral to your reef tank? Browse our LPS corals for sale and explore healthy corals for your aquarium.

Shop Cynarina and LPS Corals

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Final Thoughts

Cynarina donut coral is a beautiful and rewarding LPS coral when it is given stable water quality, balanced lighting, moderate flow, careful feeding, and safe placement. With proper care and close observation, it can become one of the most impressive and colorful corals in a reef aquarium.

Frequently Asked Questions

Q: Is Cynarina donut coral beginner friendly?
A: It is usually better in a stable reef tank, though it can be kept successfully by careful hobbyists who avoid major swings and rough handling.

Q: What lighting does Cynarina need?
A: Moderate to moderately high lighting is usually a strong starting point, with gradual acclimation.

Q: Does Cynarina need feeding?
A: Yes, supplemental feeding can help. Small meaty foods once or twice a week often support better tissue fullness and health.

Q: What flow is best for Cynarina donut coral?
A: Moderate indirect flow is usually best because it keeps the coral clean without irritating fleshy tissue.

Q: Why is my Cynarina losing inflation or color?
A: Common causes include unstable water quality, lighting stress, poor placement, rough handling, or irritation from nearby corals.

About the Author

Scott Shiles is the owner of ExtremeCorals.com, which he has operated for over 25 years and is recognized as one of the early dedicated live coral websites on the internet. A lifelong reef keeper since 1984, Scott has decades of hands-on experience maintaining marine aquariums and previously owned and operated a brick and mortar aquarium retail store for 10 years, including five years alongside Extreme Corals. He holds a degree in Marine Biology and has personally selected and sold hundreds of thousands of live corals. An avid scuba diver who has explored reef systems around the world, Scott shares practical coral care and husbandry knowledge based on real world reef experience.