koraller

Koraller, termed corals in English, are marine invertebrates that form colonies of genetically identical polyps. They belong to the phylum Cnidaria and the class Anthozoa. The reef-building subset, the hard corals or scleractinians, secrete calcium carbonate skeletons that accumulate over time to create coral reefs, complex structures that host many marine species.

Most corals live in shallow, sunlit tropical waters. They commonly form a symbiotic relationship with photosynthetic algae called zooxanthellae, which reside within coral tissues and provide energy through photosynthesis. In return, the corals offer a protected habitat and access to nutrients. This partnership makes corals highly sensitive to changes in temperature and light.

Corals reproduce both sexually and asexually. Many species synchronize spawning events, releasing eggs and sperm into the water, with fertilized eggs developing into free-swimming planula larvae that settle to form new colonies. Asexual reproduction, including budding and fragmentation, helps colonies grow and recover after damage.

Coral reefs support extraordinary biodiversity and provide ecosystem services such as coastal protection, fisheries, and tourism. They act as natural barriers against storms and help sustain local economies. However, koraller face increasing threats from climate change, including ocean warming and acidification, as well as pollution, overfishing, sedimentation, and disease. Conservation efforts include marine protected areas, sustainable tourism, reef restoration, and research into resilient coral varieties.