Types of Corals in the Red Sea

Introduction

The Red Sea hosts exceptional coral diversity. More than 200 hard-coral species and many soft corals thrive under high salinity, warm water, and low nutrients. These conditions selected for resilience unmatched in many other regions.

Hard Corals (Scleractinia)

Hard corals build reefs by depositing calcium carbonate skeletons that create habitat and coastal protection.

Key Hard-Coral Groups

• Branching corals: Acropora form fast-growing, tree-like structures that shelter fish and invertebrates.
• Branching/submassive: Pocillopora verrucosa (cauliflower coral) thrives in shallow, high-energy zones.
• Massive corals: Porites lutea build long-lived domes that dominate many fringing reefs.
• Brain corals: Favia with maze-like ridges tolerate waves and temperature swings.
• Encrusting/plate: Montipora stabilize substrate as plates or crusts.
• Submassive: Goniastrea with tight corallites add density and strength.

Soft Corals (Alcyonacea)

• Pulsing corals: Xenia show rhythmic polyps that aid fluid exchange.
• Tree-like soft corals: Dendronephthya in vivid colors on deeper slopes.
• Leather corals: Sarcophyton with tough tissues common on reef flats.

Fire Corals (Hydrozoa: Millepora)

Not true corals but reef-forming hydrozoans. Millepora grow quickly, resemble hard corals, and carry nematocysts that can sting. They often colonize disturbed patches and add structural complexity.

Unique Red Sea Adaptations

• Heat tolerance: Many species tolerate summer peaks near 32 °C.
• High salinity: Reefs persist at ~40–42 PSU where other regions struggle.
• Symbionts: Associations with heat-tolerant Symbiodiniaceae support resilience.
• Gulf of Aqaba signal: Northern reefs show notable resistance to bleaching.

Why These Reefs Matter

Red Sea reefs support fisheries, tourism, shoreline protection, and over a thousand fish species. Protecting water quality, curbing physical damage, and responsible coastal use help keep this resilient system intact.