Home > Indian History > History of India > Sea Urchins
Sea Urchins
Sea Urchins are of three types which include true Sea-urchins, Cake-urchins and Heart-urchins. These are mostly found in low tide areas clinging to rocks.

Share this Article:

Sea Urchins, Indian Marine SpeciesSea Urchins are perhaps the most capricious fantastic of all echinoderms. They look like prickly balls or small rolled-up hedgehogs. Their size varies from four to twenty five centimetres. They are widely distributed in all shallow and coastal waters in the cracks and crevices of rock pools or amidst soft seaweeds. The deep-water forms are gregarious, covering large areas of the bottom. In appearance a sea urchin is very different from an armed starfish; yet it has the same fundamental structure. Especially it is a starfish and its globular form is the result of its five radial arms having bent upwards and united along their margins and tips.

Sea Urchins, Indian Marine Species In starfish the skeletal plates are only loosely connected by fibrous tissues but in a sea-urchin the plates are fused to form a hard shell enclosing all the soft parts of the animal including the tube-feet. The mouth however is uncovered. In life the plates are covered with slime outside and within and also between each plate. In a growing urchin these plates are continually thickened by a deposit of fresh limy matter formed by the action of slime and sea water. Additional plates are also added where the tips of the arms converge. Radiating upwards from the mouth along the arms are five bands of small holes through which the tube-feet can project. The pincers (pedicellarias) in a sea-urchin are most specialized than those of starfish in that they are stalked and have three jaws. The spines covering the entire body are brittle, long, sharp and movable. They aid the tube-feet in locomotion. It is a sight to see a sea-urchin moving on the tips of its spines, putting forth here and there its whiter elastic tube-feet. When some of the tube-feet shoot and touch the ground, those already in contact with the ground are pulled back. In a short time the protruded ones are withdrawn and the retracted ones projected and through this operation of the tube-feet coming out and going in the animal progresses. The enemies of sea-urchins are large fishes.

There are three types of sea-urchins - the true Sea-urchins which are globular, Cake-urchins with almost circular and flattened bodies, and Heart-urchins shaped like a heart. Sea-urchins are coloured differently in purple, green, ochre and blue. Under each type there are several interesting forms along Indian coasts.

Temnopleura toreumaticus is commonly found on Chennai beach. It is slightly conical in shape about four centimetres in diameter. The shell is greyish brown covered with somewhat long and reddish spines banded white. Stomopneustes variolaris is a big urchin with very long and thick spines mounted on tubercles and coloured purple. They are found at extreme low tide clinging to rocks. Among Cake-urchins several species of the genus Echinodiscus are common. They are recognised by the pair of oblique slits continuous with or near to the hind margin of the shell. One of the commonest Indian Heart-urchins is Echinolampas, having a slanting appearance and prominent petal markings.


Share this Article:

Subscribe to Newsletter
Learn unknown facts about India from a curated list of informative articles.

Related Articles

More Articles in History of India

History of Indian Drama
History of Indian Drama is rich with Vedas and Indian epics and has gradually changed with time and remains unaffected by any foreign influence.
History of Khajuraho Temple
Located in the Chhatarpur district of Madhya Pradesh, Khajuraho is country’s most magnificent groups of temples.
History of Ayurveda
History of Ayurveda dates back to 5,000 years old and is widely considered to be the oldest form of health care in the world.
History of Uttar Pradesh
The state was the heart of Mahabharata war and the history of Uttar Pradesh is very much the history of India. The place finds its mentions in Hindu epics Ramayana and Mahabharata.
History of Indian Photography
An overview of the development of photography, through the various stages in India.
History of Delhi
History of Delhi began with the advent of Indian regal dynasties. Delhi witnessed the rise and fall of Hindu dynasties, Muslims and the British as well.
History of Indian Radio
History of Indian Radio dates back to late 1930s with the first establishment of All India Radio in 1936 that improved further after independence.
History of Punjab
History of Punjab dates back to the 16th century; however its formation is traced in the great epic Mahabharata.
History Of Archaeology In India
History of archaeology in India contributes a lot to define the past history and the social life of India.
History of Maharashtra
Maharashtra, the land of charismatic Marathas, unfolds the legend of diverse culture and tradition, keeping in pace with the modernity. The gallant history of Maharashtra is still echoed amidst its historical relics and archeological wonders.
History of Kerala
History of Kerala can be interpreted from the inscriptions of Ashoka, Mauryan Emperor. History of Kerala is as interesting as its wide-ranging geographical features that make the land a place of versatile appeal.
History of Bihar
History of Bihar goes back to the very dawn of the human civilizations. Many eminent personalities and leaders from Bihar contributed for India’s freedom struggle.
History of Assam
In the ancient Indian epics like Ramayana and Mahabharata, Assam was known as `Kamarupa` or `Pragjyotish`. In the Mahabharata, the Puranas, the Tantras there are references of Assam as Kamrupa kingdom.
History of Andaman and Nicobar Islands
History of Andaman and Nicobar Islands dates back to the settlement of the East India Company in the territory of the Islands.
History of West Bengal
History of West Bengal is rooted in richness and is an important episode in the history of India. The history of Bengal played an important role in shaping the history of India.
History of Jharkhand
One of the fairly newer states, Jharkhand was carved out of the southern portion of Bihar in 2000. The history of Jharkhand is seeped with a variety of cultural significances starting from the Vedic era to Mughal period and finally the British administration.
History of Sikkim
History of Sikkim declares the pre historic culture and the colonial era hilly politics and the rules of Sikkim.
History of Nagaland
The history of Nagaland mainly revolves around and deals with the customs and economic activities of the Naga Tribes and how the state has evolved since the Indian Independence.
History of Mizoram
History of Mizoram includes the various historical events and incidents which occurred during the various ages, right from before the age of the Mughals.
History of Jammu & Kashmir
History of Jammu and Kashmir involves a series of political and geographical transformations from every ancient era to the modern times also. Even now, Jammu and Kashmir has its political tension between Pakistan and India.
History of Puducherry
Puducherry was invaded by different invaders in different times. The invaders include Pallava Kingdom of Kanchipuram, dynasties of the South, Cholas of Thanjavur, Pandyas and Muslim invaders.
History of Chandigarh
In 1947, the British India was partitioned into India and Pakistan. Punjab was also included in this partition. So, there was a need for a new capital for Punjab, as the old capital Lahore became part of Pakistan during the partition. So, in 1948, under the leadership of chief architect Mr. P.L. Verma the construction of Chandigarh city began.
History of Daman and Diu
During the early stage, i.e. from 8th to 13th century, Daman and Diu was part of Goa.
History of Lakshadweep
History of Lakshadweep defines the first settlement on these islands under the Union Territory of India that was ruled by Cheraman Perumal, who was the last king of Kerala.
History of Karnataka
History of Karnataka comprised of the different rulers of different dynasties of various religions like Hindus, Buddhists, and later the Muslims.
History of Goa
History of Goa dates back to the 3rd century BC and reflects the rule of the mighty rulers and gained its independence under Jawaharlal Nehru.
History of Arunachal Pradesh
Arunachal Pradesh possesses a rich historical heritage of culture of the ancient tribes. Being a bordering state of India, Arunachal Pradesh also has a history of military unrest since ancient Indian age.
History of Andhra Pradesh
History of Andhra Pradesh traces its origin back to the 5th century BC. According to the inscriptions, Kuberaka, the oldest Kingdom in South India had an empire in the coastal Andhra during that period.
History of Himachal Pradesh
History of Himachal Pradesh narrates about the various settlements and dynasties that emerged in the region over time.
History of Uttarakhand
History of Uttarakhand finds mention in the early Hindu scriptures as Kedarkhand, Manaskhand and Himavat. Uttarakhand is called as the Land of the Gods (Dev Bhoomi) because of its various holy places and shrines.
History of Rajasthan
The history of Rajasthan is dotted with tales of valor, chivalry, camaraderie and romance.
History of Tamil Nadu
History of Tamil Nadu reveals that this ancient place in South India was ruled by various kingdoms like the Pandyas Dynasty, Cholas Dynasty, Nayakas Dynasty and Pallavas Dynasty.
History of Haryana
History of Haryana depicts various events and influences that have cast a profound effect on the culture and people of the district. The place gained statehood on 1st of November 1966
History of Odisha
History of Odisha goes back a rather long way. Most of the history of the state is replete with the dynastic as well as tribal struggle for territorial superiority. Odisha is a place where one can find the religion, culture and history flow in away that lead to cultural amalgamation of early India.
History of Manipur
History of Manipur can be traced back to the prehistoric ages and this was followed by a number of rulers who reigned the land from age to age till it came under British rule and later joined the union of India.
History of Gujarat
History of Gujarat can be dated back to the 14th century that later witnessed the supremacy of many powerful dynasties.
History of Tripura
History of Tripura is dealing with the early mythological history and the history of British rule in North eastern part of India.
History of Meghalaya
The history of Meghalaya predominantly comprises of the three tribes of the state- Garo, Khasi and Jaintia tribes. Later on Meghalaya was formed by carving out two districts from the state of Assam.
History of Chhattisgarh
History of Chhattisgarh dates back to the era of epics and traces through the reign of powerful dynasties in India like Marathas. The area developed a rich cultural heritage during British era.