Nature · 2
During prolonged heat stress, what do coral polyps expel that directly causes the phenomenon known as coral bleaching?
Answer
Their symbiotic algae
Coral polyps host algae called zooxanthellae, which give coral its color and much of its food via photosynthesis. When ocean temperatures rise, corals expel these algae, leaving behind a pale, translucent skeleton — the visual effect known as bleaching.
💡 Did you know?
Coral polyps expel their algae partners during heat stress, then starve without them—bleaching is essentially a symbiotic breakup caused by warming oceans.
Other options people guess
- Their protective mucus coating
- Their calcium carbonate skeleton
- Their stinging nematocyst cells
Topics
- symbiosis
- coral-reefs
- ocean
- climate
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