Four new corals recorded from Indian waters

Published: 2nd Jul, 2022

Context

Scientists have recorded four species of azooxanthellate corals for the first time from Indian waters.

About

What are azooxanthellate corals?

Azooxanthelate corals are a group of corals that do not contain zooxanthellae and derive nutrition not from the sun but by capturing various forms of plankton.
They belong to the genus Truncatophlebellum(belong to the same family Flabellidae) from Indian waters.
However, the zooxanthellate corals are restricted to shallow water only unlike azooxanthellate.

Key-highlights of the findings

The four species found are:
- Truncatoflabellum crassum
- incrustatum
- Irregular
- Krasum
They are non-reef building, solitary corals.
These groups of corals are deep-sea representatives, with the majority of species reporting from between 200 m to 1000 m.
Their occurrences are also reported from shallow coastal waters.

Why does the location matter?

These findings were made in the waters of Andaman and Nicobar Islands.
About 570 species of hard corals are found in India and about 90% of them are found in the waters around Andaman and Nicobar Islands.
Andaman and Nicobar are one of the ancient and oldest ecosystems of corals that share less than 1% of the Earth’s surface but they provide a home for about 25% of marine life.

What are the ideal environmental conditions for corals to grow?

Corals in India

India is recorded to have around 7,517 km of coastline but only 6,100 km represents the mainland coastline. The three major types of coral reefs found in India are fringing, barrier and atolls.
Coral reefs in India are found in a lot of areas including the Gulf of Kutch, Gulf of Mannar, Palk Bay, Andaman & Nicobar and Lakshadweep Islands. The Gulf of Kutch in the northwest has some of the most northerly reefs in the world.
Patches of coral reefs are also found in Ratnagiri, Malvan and Redi, south Bombay and at the Gaveshani Bank located in the west of Mangalore.

Types of coral reefs in India

India has three major prevailing types of coral reefs:

Fringing reefs: Fringing reefs evolve and develop near the continent and remain close to the coastline. These reefs are separated from the coastline by small, shallow lagoons. They are the most commonly found reefs in the world.
Barrier reefs: Barrier reefs are found offshore on the continental shelf. They usually run parallel to the coastline at some distance. A deep and wide lagoon is located between the coastline and the barrier reef.
Atolls: Atolls are formed on mid-oceanic ridges. They are shaped circularly or elliptically and are surrounded by seas on all four sides and have shallow waters in the center called a lagoon.

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