---
title: Hard corals (Scleractinia)
scientific_name: Scleractinia
common_name: Hard corals
rank: Order
published: 2024-11-19T18:41:51.573Z
updated: 2026-08-03T21:00:13.429Z
tags: Hard corals, Scleractinia, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/invertebrate/stinging/hard-corals
---

# Hard corals (*Scleractinia*)

## Quick facts

- **Rank:** Order
- **Scientific name:** Scleractinia
- **Body shape:** Invertebrate - Not a fish - coral, mollusc, crustacean, echinoderm and other invertebrate groups.
- **Species listed here:** 12

## How to recognise this group

- diverse colony shapes: branching, massive, encrusting, plate-like
- surface covered by polyps, often with visible tentacles
- varied colours of brown, green, yellow, or pink
- tentacles often extended, more so during night feeding

Hard corals (Scleractinia) are marine cnidarians that secrete a rigid, calcareous external skeleton, forming the diverse structures of reefs. Each animal is a polyp, typically a few millimeters wide in colonial forms, or up to 25 cm (10 in) in diameter in solitary species. Polyps have a cylindrical body with an oral disc, a central mouth, and surrounding tentacles. Colonies build complex formations, ranging from branching and encrusting to massive boulders and plate-like structures, often spanning several meters in diameter or height. Their colours vary, appearing brown, green, yellow, or pink, often due to symbiotic algae.

These corals constitute the dominant structural component of most shallow reefs. They thrive from sunlit reef flats to deeper slopes, occurring down to depths of 60 m (200 ft). Most species host symbiotic zooxanthellae, which live within their tissues and provide the majority of the coral's energy through photosynthesis. Polyps supplement this diet by extending their tentacles, primarily at night, to capture plankton from the water column.


## Species (12)

- [Acropora Microclados (Acropora microclados)](https://redseacreatures.com/taxon/invertebrate/stinging/hard-corals/acropora-microclados)
- [Black Sun Coral (Tubastraea micranthus)](https://redseacreatures.com/taxon/invertebrate/stinging/hard-corals/black-sun-coral)
- [Brain Root Coral (Lobophyllia corymbosa)](https://redseacreatures.com/taxon/invertebrate/stinging/hard-corals/brain-root-coral)
- [Bubble Coral (Plerogyra sinuosa)](https://redseacreatures.com/taxon/invertebrate/stinging/hard-corals/bubble-coral)
- [Ctenactis Crassa (Ctenactis crassa)](https://redseacreatures.com/taxon/invertebrate/stinging/hard-corals/ctenactis-crassa)
- [Herpolitha Limax (Herpolitha limax)](https://redseacreatures.com/taxon/invertebrate/stinging/hard-corals/herpolitha-limax)
- [Lesser Valley Coral (Platygyra daedalea)](https://redseacreatures.com/taxon/invertebrate/stinging/hard-corals/lesser-valley-coral)
- [Mountainous Star Coral (Orbicella faveolata)](https://redseacreatures.com/taxon/invertebrate/stinging/hard-corals/mountainous-star-coral)
- [Orange Cup Coral (Tubastraea coccinea)](https://redseacreatures.com/taxon/invertebrate/stinging/hard-corals/orange-cup-coral)
- [Spreading Rice Coral (Montipora patula)](https://redseacreatures.com/taxon/invertebrate/stinging/hard-corals/spreading-rice-coral)
- [Wettstein's Cup Coral (Rhizopsammia wettsteini)](https://redseacreatures.com/taxon/invertebrate/stinging/hard-corals/wettsteins-cup-coral)
- [Yellow Scroll Coral (Turbinaria reniformis)](https://redseacreatures.com/taxon/invertebrate/stinging/hard-corals/yellow-scroll-coral)

---

*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/invertebrate/stinging/hard-corals)*
*Updated: August 3, 2026*