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Overview of Corals
- Day/Night Cycle of Corals
- Types of Corals
- Corals have six smooth tentacles. Common types on the Reef include brain and staghorn coral.
- Soft corals grow wood-like cores and fleshy rinds instead of stony skeletons.
- Coral Characteristics
- Coral polyps stay inside their skeletons during the day. At night, polyps extend tentacles to feed.
- Coral skeletons are made of calcium carbonate.
- Coral Behavior
- Corals attach permanently to reef spots.
- Corals are nocturnal feeders.
Nighttime Behavior of Corals
- What do corals do at night?
- At night, coral polyps come out of their skeletons to feed, stretching their long, stinging tentacles to capture critters.
- Algae helps coral by producing food and oxygen.
- Do corals grow at night?
- Most corals more actively feed at night.
- In the wild, corals seem to feed more actively at night rather than during the day.
Corals’ Nocturnal Cycle
- Is it normal for corals to close up at night?
- Corals exhibit daily behavior patterns, including a period of rest at night.
- The reason torch corals close up at night is to photosynthesize during the dark hours.
- What if corals close up during the day?
- Once water quality issues are ruled out, further investigation is needed if coral closes up during the day.
- Lighting Recommendations for Corals
- No, corals don’t need light at night to survive. Leaving the lights on at night can disturb fish and disrupt their circadian rhythm.
