Scleractinia
Scleractinia, also known as stony corals, are an order of marine animals that form colonies of tiny individual polyps. These polyps secrete a hard, calcium carbonate skeleton that forms the characteristic structure of coral reefs. Scleractinian corals are crucial to the health of marine ecosystems, providing habitat and food for countless organisms. They are found in tropical and subtropical waters around the world, playing a significant role in the biodiversity of these regions.
Common Names
Scleractinian corals are commonly known as stony corals, hard corals, or simply corals. The term "stony" refers to their hard, calcium carbonate skeletons.
Characteristics
Scleractinian corals are characterized by several distinct features:
- Coloniality: Corals live in colonies of interconnected polyps, each with its own mouth and tentacles.
- Calcium Carbonate Skeleton: Polyps secrete a hard, calcium carbonate skeleton that forms the structure of the coral reef. The skeleton can be various shapes and sizes, from branching to massive.
- Symbiosis with Zooxanthellae: Most scleractinian corals have a symbiotic relationship with single-celled algae called zooxanthellae. These algae live within the coral tissues and provide energy through photosynthesis.
- Polyp Structure: Each polyp has a mouth surrounded by tentacles, used to capture food.
- Reproduction: Corals reproduce both sexually and asexually. Sexual reproduction involves the release of sperm and eggs into the water, while asexual reproduction occurs through budding or fragmentation.
Environments
Scleractinian corals are predominantly found in tropical and subtropical waters, specifically in shallow, clear water environments. They require sunlight for their symbiotic zooxanthellae to photosynthesize. These environments include:
- Coral Reefs: These are the most well-known habitats for scleractinian corals. They provide a diverse and complex ecosystem for a wide variety of marine life.
- Lagoons: These sheltered bodies of water provide a calm and nutrient-rich environment for corals to thrive.
- Sea Mounts: These underwater mountains offer a suitable habitat for corals, especially in deeper waters.