In a remarkable discovery, scientists have unearthed four species of Azooxanthellate Corals under the Genus Truncatoflabellum (Scleractinian: Flabellidae) from Indian waters for the first time. These include Truncatoflabellum crassum, T. incrustatum, T. aculeatum, and T. irregulare. Prior to this, these varieties of corals had been reported only from Japan, the Philippines, Australian waters, with T. crassum found in the Indo-West Pacific distribution, including the Gulf of Aden and the Persian Gulf.
The Specifics
The newly discovered coral species reside in the waters of the Andaman and Nicobar Islands. They are classified as Azooxanthellate corals, a group that does not host zooxanthellae and mainly derive nourishment from different forms of plankton. Contrary to their counterparts, the Zooxanthellate corals that thrive in shallow waters, Azooxanthellate corals exhibit a highly compressed skeletal structure. In India, approximately 570 species of hard corals have been identified, with nearly 90% of them being located in the waters around the Andaman and Nicobar Islands.
Coral Ecosystem
Though they occupy less than 1% of the earth’s surface, corals host nearly 25% of marine life. Hence, even though limited, their ecosystem is robust and vital. The Azooxanthellate corals are deep-sea representatives, with most species found between 200 m and 1000 m beneath the ocean’s surface. However, some also inhabit shallow coastal waters.
The Significance of the Discovery
The findings have significant implications for understanding the zoogeographic distributional ranges of these four newly discovered species. In India, most studies about corals have focused on reef-building types, leaving non-reef-building corals considerably unexplored. This discovery not only broadens our knowledge about non-reef-building, solitary corals but also enhances India’s national database of biological resources.
Understanding Corals
Corals consist of genetically identical organisms, known as polyps, which host microscopic algae called zooxanthellae within their tissues. This symbiotic relationship enables the corals to receive necessary compounds for photosynthesis from the zooxanthellae. In return, the zooxanthellae obtain organic products from the coral polyps, which they use to create their calcium carbonate skeletons. Apart from providing essential nutrients, zooxanthellae contribute to the unique and stunning colors of corals. Consequently, corals are often referred to as the “rainforests of the seas”. Corals are divided into two categories: Hard, shallow-water corals that construct reefs, and soft and deepwater corals, which are found in dark, cold waters.