Want this in your inbox? Click here.
Worldly known as starfish, they are a type of echinoderm that live in the ocean. They have a star-shaped body and usually five arms radiating outward from their central body, although some species may have more. Despite the name, sea stars are not fish. They are a type of invertebrate that use their tube feet to move, feed, breathe, and even reproduce. Those tube feet have an exoskeleton made of calcium carbonate plates.
Do not have brain
Sea star do not have brain but their nervous system is distributed throughout its body, allowing it to respond to external stimuli. They have a unique way of digesting their food, by everting their stomach out of their bodies.
Appearance
Starfish are found in a variety of sizes, from less than an inch to more than a foot in diameter. They can be found in most of the world's oceans, from warm tropical waters to cold icy waters. Their color can range from bright oranges and purples to pale blues and whites.
Population
The current global population of sea stars is unknown, but their population is declining due to overfishing, climate change, and pollution. They are considered a keystone species in many marine ecosystems, meaning they play an important role in maintaining balance in their environment.
Regeneration
Sea stars also have an incredible regenerative ability, allowing them to regrow lost arms and even completely reconstruct from a single arm part. This ability has made them a very important species in the study of regenerative medicine. All of their vital organs are located in their arms, so they can survive if some of them are lost.
Feeding
Starfish are carnivores, feeding on mollusks, fish, and other invertebrates. They will usually hunt at night, using their tube feet to move along the ocean floor and reach out to catch their prey. They have powerful suction cups on the end of their arms which they use to pry open their prey's shell and then insert their stomach into the opening and digest their meal.
May they be harmful when attach to human skin?
No, Sea stars are not harmful to humans, although their spines can cause irritation if touched. They also have venomous glands in their tube feet and spines, but it is not strong enough to penetrate human skin. They are more of a nuisance if they attach themselves to boats or docks, but can be easily removed.
More interesting articles about ocean:
If you have found something that is not correct, do not hesitate to give us a comment and let us know. And if you donate an extra $5 to our ally organizations, we will put your name in a donate list and everybody will know about your great heart. Thank you so much for your feedback.