In the Andaman Islands, the various Andamanese people maintained their separated existence through the vast majority of this time, diversifying into distinct linguistic, cultural and territorial groups.
Aborigines and tribes
It is believed that the Andaman aboriginal might have reached this Island early in time, possibly by boat from Southeast Asia since they show a strong affinity to the Semang of Malaysia and the Aetas of the Philippines.
However, a recent DNA match is indicative of a direct link with pygmies of Southern Africa.
The Nicobar is must have migrated sometime before the Christian era.
The origin of Andaman Aboriginals are primary hunter-gatherers, where are the Tribes of Nicobar are mainly horticulturist and herders.
Sentinelese continue to be hostile to outsiders, where are the ones ferocious Jarawas are gradually becoming friendly to civilized population. Onges and Great Andamanese have accepted the presence of outsiders. The Nicobarese have integrated well with outsiders and have joined the Indian mainstream.
Shompens still avoid contact but are nonhostile.
The indigenous peoples of the Nicobars (unrelated to the Andamanese) have a similarly isolated and lengthy association with the islands. There are two main groups: the Nicobarese, or Nicobari living throughout many of the islands; and the Shompen, restricted to the interior of Great Nicobar.
Barren island:The only live volcano in the Indian peninsula, barren life around 120 km North East of Port Blair in Andaman sea. This tiny almost circular Island cover and area of about 8 square kilometre and has diameter of about 3 km it belongs central sunda group and and is believed to be born out of an eruption which occurred during the late pleistocene period.
Later in the course of geological evolution the prime giant cone got transform to the present day Barren.
The existing cone in fact, is the central part of blow off Cauldron. Contrary to its name there in the island is fully covered with lush green forest and his inhabited by 13 species of birds, 10 species of butterflies and 9 species of insects, 7 species of mammals, who is species of each Centipede and spiders. Down the mammals included as stock of feral goats, which have adopted the answer to the terror and depend on sea water to survive in absence of a perennial freshwater source on the island. It is believed that The Goats reached the island following a shipwreck in the region.
By the 1850s when they first came into sustained contact by outside groups, the indigenous people of Andamans were: the Great Andamanese, who collectively represented at least 10 distinct sub groups and languages; the Jarawa: the jungle (or Rutland Jarawa); the Onge; and the Sentinelese (the most isolated of all the groups).
About 940 species of echinoids are recorded in the word with 113 species known from Indian seas.
The globular cell is provided with sharp pointed spines.
The numerous tube feet on lower side formally attached the individuals to the hard sub stratum.
They are mostly Herbivorous and control the excessive growth of algae, which is detrimental to the health of live corals.
Their long fragile Spine and poisonous globiferous pedicellariae protect from several Predator organism. Sum of urchins such as stomopneustes variolaris, Echinometra mathaei and Echinometra molar is bole Tun Rock and dead Coral bases.
The flats and dollars, cake urchins and heart shaped heart urchins inhibit 10 of substrate are and subsist on their organic content. Sea urchins produce antibacterial substance in the skin.
A true Reef building stony coral maybe unisexual or bisexual. In sexual processes The Breed together once in a year at a predetermined time after Dusk, a day or two before the spring full moon. Male and female sperm is releases in millions of pink balls. These balls burst and the process of fertilization is completed.
This Process,at places, show intense Tata water stays pinkish till next morning. A large number of pink corals are released in the open Sea this way.
After sometime these baby Coral settle over a suitable substratum and start forming new colonies through a asexual reproduction. Dear morphological features change with environment in which they settle.
Andaman Reef Builders
Coral reef all over the world are the handiwork of hermatypic Reef Builders.
In these islands there are two cheif Reef builders namely Porites and Favia.
The Other forms present here such as favites, platygyra, symphyllia, ganiasprea and diplostrea(brain corals) are the Associates Reef builders.
These corals create massive dome shaped colonies creating shelter for other branching and delicate form such as Acropora(stag horn corals)
Pocillopora (thorny Coral), stylophora(birds nest) and Montipora to establish.
All the massive and branching forms named above are sedentary and colonial.
However, there is also a solitary Coral, which belongs to family Fungiidae popularly known as Mushroom Coral.
The hawksbill Turtle is critically endangered sea turtle. It is only species in its genus. The species have worldwide distribution Eretomchelys imbricate is the Atlantic subspecies, while Eretomchelys imbricate bissa is found in indo-pacific region.
While the turtles lives a part of its life in the ocean, Is most often encountered in Shallow Lagoon and coral reef where it feed on the sea sponges.
In addition the sponge is that Hawksbill heat are usually those with high silica content, making the tortoise one of you animals capable of eating siliceous organism. They also feed on other invertebrates, comb jellies and jellyfish.
Shells are perhaps the most colourful and fascinating object known to mankind other than changed since time immemorial.
They served as money, ornaments, and musical instruments, drinking cups, in magic and in the making of fine porcelains. They are also the symbol of ritual and religious observances.
Shells form by soft bodied creature known as ‘mollusc’.the
Soft body animals, which live inside the cell is covered with a thick layer of specialised epithelium cell known as mentle, which is turn secretes are too tired shell material making the shell.
The outer layer having a different colour pattern is organic in constitution, technically called ‘periostracum’.
Calcium ions from the environment are absorbed into the blood and deposited evenly under this layer.
The next inner layer is called’ nacre ‘or’ mother of pearl’ responsible for pearly lustre common to many shells.
These Island are traditionally known for their shell wall specially Turbo, Trochus, Murex and Nautilus.
These shells are supporting many cottage industries producing a wide range of decorative items and ornaments.
For back in time someone 50 million years ago molten magma might have used from Earth’s crust along the dilated ocean floor food of submarine Ridge. Phenomena appears to have taken a long time does creating mid- Ocean rise known to many geologists as whale back tumors.
This island with a few exceptions are volcanic in origin. We are in the fact at the tip of risen undulating Lava plateau, the core of which goes deep down beyond the ocean floor. Conformity with the expanding earth theory.