Starfish belong to the Echinodermata starfish class, a big family of marine animals with a flattened, star-shaped body and a mouth in the center of the lower part.

The number of arms protruding from the body plate is generally five, but some species have six or more. The interior of these arms contains the gonads and digestive glands, which perform various essential functions in the body.

Despite their relatively small size, starfish come in a wide range of colors and sizes. Most species of starfish are found in the Pacific Ocean, and they vary in body color from red, orange, and purple, to cyan.

There are about 1,800 species of starfish in the world, with approximately 1,500 living on the sea floor. Starfish are widely distributed, from the warm tropics to the cold frigid seas, and even in the abyss 6,000 meters below the ocean surface.

The whole body of a starfish is composed of many calcareous bone plates combined by connective tissue, with prominent appendages such as spines, tumors, or warts on the body surface.

The echinoderm skin of starfish contains tiny crystals that act as perspective mirrors, capturing important information about the surrounding environment. These crystals gather light so well that they capture light from all directions at the same time, making it difficult to attack starfish from behind.

Starfish are ravenous carnivores, preying on slow-moving marine animals such as shellfish, sea urchins, crabs, and sea anemones. They generally have two stomachs, one of which can be ejected from the body.

With their powerful tentacles, starfish can pry open strong shells and then spit a stomach into the shell, digesting the meat directly inside. This special skill of external digestion allows starfish to eat food several times larger than their own size.

While humans find starfish fascinating, they are currently facing a significant problem caused by the crown-of-thorns starfish species. Crown-of-thorns starfish are notorious killers of corals, which are underwater gardens in the sea and habitats for fish and many types of marine life.

The coral reef itself is formed by the skeleton of coral polyps in the process of growth and accumulation for hundreds to thousands of years.

The crown-of-thorns starfish is responsible for nearly half of the Great Barrier Reef's disappearance in Australia. To save the Great Barrier Reef, the Australian government has developed a new method to kill 250,000 crown-of-thorns starfish within two years.

The destruction of coral reefs by the crown-of-thorns starfish species poses a threat to the marine ecological chain, and the loss of coral reefs could have unpredictable and devastating consequences.

Starfish may look beautiful and graceful, but they are deadly predators in the aquatic world. With their unique digestive abilities, they can devour marine animals several times their size.

Although they play an essential role in maintaining the balance of the marine ecosystem, some starfish species, such as the crown-of-thorns starfish, can cause significant damage to the environment. It is vital to protect and conserve the delicate marine environment and prevent the loss of coral reefs which are critical to the survival of marine life.

In addition to the destruction caused by crown-of-thorns starfish, starfish have also become a popular food in some countries.

In certain cultures, they are considered a delicacy and are served in a variety of ways, such as deep-fried, boiled, or dried. In some areas, they are also used in traditional medicines.

However, the overconsumption of starfish can have negative effects on the marine ecosystem.

Since starfish are predators of many slow-moving species, such as mollusks and crustaceans, their overpopulation can lead to a decrease in the population of these species, which can have a ripple effect throughout the food chain.

Therefore, it is important to regulate the harvest and consumption of starfish to maintain a balance in the marine ecosystem.