Sea urchins | Facts & Information

# Sea urchins | Facts & Information

Sea urchins | Discover Fascinating Facts and Information About Sea urchins

Sea urchins (Echinus melo) belong to the Echinodea class. Also called echinde are marine echinoderms animals with spherical body covered with spines.

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Sea Urchins

Sea urchins

The sea urchin is a fascinating animal that lives in the ocean and belongs to the class Echinoidea. It is known for its distinctive appearance, being equipped with sharp spines and an exceptional formation called a test, which helps it adapt to its environment and protect itself from potential predators.

These sea urchins live in various regions of the world, such as tropical, subtropical, and temperate zones of the oceans. They can be found in different colors and sizes, ranging from 2.5 cm to 30 cm in diameter.

The characteristic appearance of the sea urchin consists of hundreds of movable spines on the surface of their body. These spines help them defend against predators and also capture their food. The spines, although they may appear heavy and rigid, are actually made up of small fleshy bony plates, which are covered by a layer of keratin, a material similar to that found in the structure of human hair. They can be different colors, such as red, yellow, or purple.

The sea urchin has a rather unique feeding system. Although they can be considered herbivores, they are capable of consuming other small organisms found in their surroundings. These sea urchins feed on marine algae, with their mouth open downwards and spines pointing upwards, they move through the water in search of food, using their appendages around the mouth to perform this capturing action.

In addition to their interesting appearance, sea urchins also play an important role in marine ecosystems. They contribute to maintaining the balance in populations of marine algae. Being herbivores, these sea urchins consume algae and help maintain species diversity and ecosystem health in which they live.

However, sea urchins also face threats. Human activities such as overfishing and pollution can negatively affect the health and survival of these species. Additionally, climate change and rising water temperatures can influence the environment in which sea urchins live.

To protect and conserve these sea urchins and their habitat, it is essential to better understand their needs and behavior. Researchers and scientists are currently studying these animals to develop effective conservation strategies and identify measures to protect them and their habitat.

Sea urchins are certainly interesting and beautiful creatures of the marine world. With their unique formations and ability to adapt to the environment, these sea urchins contribute to the diversity and balance of marine ecosystems. We hope that through our efforts, we will be able to protect and conserve these creatures for future generations.










They can be found in all seas and oceans. They are related to starfish, and sea cucumbers.

Echinodermate in Greek means thorny skin.

Specifically the term sea urchin refers to regular equinoxes that are symmetrical and globular.

Feeding sea urchins

Sea urchins feed mainly on algae, but they can also feed on a wide range of invertebrates such as mussels, sponges, crinoids, etc.

Sea urchin is the favorite food of sea otters.

If left unattended by biologists, they can cause serious damage.

Appearance sea urchin

Sea urchins vary in size from 6 cm to 30-40 cm. Like starfish, they have a symmetry called pentamerism. They have 5 roughly spherical bodies of different sizes radiating at the central axis.

Their body shape sometimes varies to oval shape with degree of bilateral symmetry. Due to the activity the lower part is slightly flat, and the upper part can be slightly bulging.

This irregular shape has evolved to allow animals to penetrate the sand or other accessible places. Internal organs are covered with a thin layer of dermis and spiderma.

Sea urchins have five pairs of estern gills located around the mouth that constitute the main breathing organs.

The lower part, the one that meets the ground contains the oral cavity. The spines are long and sharp to protect the animal's body from predators.

It is not entirely clear, but it seems that in some species these spines contain venom. Common sea urchins have spines 1-3cm long and 1-2mm thick.

In the Caribbean there are sea urchins that have spines ranging in length from 10 to 30 cm.

Behavior sea urchin

At first glance the sea urchins seem incalculable to move. The most visible sign that they are alive is given by thorns.

Most direct their thorns to the touch point to fend off potential predators. Hedgehogs have no eyes in sight, legs or other means of locomotion, but they can move freely on hard surfaces with the help of thorns.

The nervous system has a relatively simple appearance. He has no brain. The nerve center consists of a ring of numerous fine nerfs that surrounds the oral cavity on the inside.

They are sensitive to touch, light and chemicals.

Breeding sea urchins

In most cases the eggs float freely in the sea water, but some species keep them between the Thorns thus providing protection.

The fertilized egg develops in less than 12 hours. Initially appears a ball of cells that turns into a larva.

The Larva has an elongated shape and does not need to feed.

It may take several months for the larva to develop.

First it begins with the formation of the outer surface around the mouth and anus that are almost in the same area. Some species reach maturity after 5 years.

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Sea urchins | Facts & InformationSea Urchins | Discover Fascinating Facts and Information About Sea Urchins