what makes up coral

Coral is made of tiny living animals called polyps that build a hard skeleton of calcium carbonate (a limestone-like mineral), along with soft tissues and symbiotic algae living inside them.

What makes up coral? (Quick Scoop)

• Living polyps – Small, tube-shaped animals with a mouth and tentacles, related to jellyfish and sea anemones.

• Calcium carbonate skeleton – In hard (stony) corals, polyps secrete a rigid outer skeleton made of calcium carbonate that forms the structure of coral reefs.

• Soft tissues – The polyp’s body is mostly soft, transparent tissue that sits in or on the skeleton (in hard corals) or on more flexible internal structures (in many soft corals).

• Zooxanthellae (algae) – Microscopic algae living inside the polyps’ tissues give many corals their color and provide much of their food through photosynthesis.

• Organic matrix and minerals – Coral skeletons are a mix of mineral (calcium carbonate, often as aragonite) plus organic compounds like proteins and sugars that help control how the skeleton forms.

In short, when you ask “what makes up coral,” it’s a combination of animal (the polyps), rock-like skeleton (calcium carbonate), and algae living together to build coral reefs.

Information gathered from public forums or data available on the internet and portrayed here.