Tuesday, May 17, 2022

Do Sea Stars Have Brains

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Discover 10 Fun Facts About The Sea Stars

Sunflower Seastar: Terrifying Predator? | National Geographic

1. They have no brain and no blood.Starfish use filtered sea water to pump nutrients through their nervous system.

2. They can live up to 35 years.

3. Starfish is not their right name, they should always be called Sea Star!Theyre actually related to sand dollars and sea urchins.They do not have gills, scales, or fins like fish do. So because they are not classified as fish, scientists prefer to call starfish sea stars.

4. There are around 2,000 species of sea star.While many species live in tropical areas, you can also find sea stars in the cold waters of the Earth, even the polar regions.

5. They cannot survive in fresh water.

6. They can regenerate.But its takes a while. It can take u to a year for a lost limb to grow back.

7. They eat inside out.When they capture prey, they have tiny suction cups to grab ahold of their food. Then their stomach exits their mouth to digest the food, and reenters the body when theyre done eating.Learn more about their anatomy on our sea star web page.

8. Sea Stars Reproduce Two Ways.Male and female sea stars are hard to tell apart because they look identical. While many animal species reproduce by only one method, sea stars are a little different.

Sea stars can reproduce sexually. They do this by releasing sperm and eggs into the water. The sperm fertilizes the gametes and produces swimming larvae which eventually settle on the ocean floor, growing into adult sea stars.

Do Fish Have Feelings

Many researchers spend a lot of time pondering the emotional status of fish. Many people think fish do not have feelings, but they are wrong. Like every other vertebrate, they have feelings and can feel pain, can be happy, sad, and even depressed.

Researchers experiments showed that fish can feel pain. They injected the fish with saline and acidic solution and placed a pain-killing solution on the other side of the tank.

They noticed the fish migrating to the parts of the tank with the painkiller, showing they felt the injections pain.

When you have two fish in the tank, and one of the two fish dies or you remove it, you will notice a change in the other fishs behavior. The fish will have reduced activity and will not eat as it does before. It shows the fish is sad or depressed about the situation of its tankmate.

You can also know your fish is happy when you feed it. You will notice the fish behavior when you move close to the tank it will be happy and swimming around waiting for you to feed it. Fish have feelings, and they will react to several stimuli around them.

Do Fish Have Memory Recall

Most people believe that fish only have a memory span of about 30 seconds. Contrary to that, fish can have a longer memory span and can recall things than you think. They can remember associations and context up to twelve days after the day it occurred.

The longer memory span also allows them to remember the face of their owner.

They will move to the surface when they see their owner expecting food but will move away when strangers come close to the tank. Other fish like salmon also have a high retentive capacity, knowing their birthplace and returning to give birth.

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They Have Eyes On The Ends Of Their Arms

While starfish may lack blood, a brain and even a central nervous system, they still need eyes to be able to navigate their watery surroundings. And because starfish are such unusual creatures, where else would their eyes be located but on the ends of their arms?

Although their eyes cant see things in the same ways that ours can the eyes, which look like small red dots, are able to detect different shades of light, allowing them to navigate through the ocean. This lets them hunt for food and avoid becoming a meal themselves.

Are Sea Stars Endangered

Do Echinoderms Have a Brain

Like many marine animals, sea stars are threatened by rising ocean temperatures, ocean acidification and pollution, and other human activity. A disease called sea star wasting disease has caused massive population losses since 2013. It has affected multiple species from New England to Mexico to Alaska. This disease is made worse by rising water temperatures, like those caused by global climate change.

The loss of any species causes a ripple effect in its habitat. For example, the endangered sunflower star helped control sea urchin populations in kelp forests on the Pacific coast. Without their natural predator, sea urchin populations are exploding and overgrazing the kelp. This in turn harms all the organisms, or living things, that rely on the kelp forests.

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How Long Sea Stars Can Live

Usually, they live for about 10 years but some species up to 35 years. They spend most of their life alone but congregate occasionally in larger groups during certain times of the year to feed or mate. Starfish capture oxygen from the water meaning if they are out of water they can die in short time since they cannot perform gas exchange.

Do Echinoderms Have A Brain

Echinoderms such as starfish , brittle stars, sea urchins and sea cucumbers do not have a brain or a brain-like organ in their bodies. The coordination of the nervous system is carried out by the nerves that radiate out from around the mouth and down into each arm or tentacle. This arrangement of nerves is called a nerve net and it coordinates the synchronization on the organisms tube feet as it moves around the ocean floor. Some echinoderms have structures called ganglia which consist of groups of nerve cells clumped together, but this morphology is not considered to be a brain.

The image above shows the necklace or tiled sea star Fromia monilis which does not have a brain but uses a nerve net to coordinate its movements on the ocean floor.

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Starfish Gallop With Hundreds Of Tubular Feet

On an extended research visit to a friends lab in Tokyo, marine biologists Amy Johnson and Olaf Ellers witnessed something theyd never seen before. The starfish in Tatsuo Motokawas lab werent content slowly gliding across the floor of their tank, they bounced and galloped, zooming around their enclosure.

For one of the most familiar animals in the sea, this was a new behavior, never before described in the scientific literature.

It was an absolute epiphany, said Johnson who studies how sea stars move and teaches marine biology along with Ellers at Bowdoin College in Maine. That moment we first saw them go faster by bouncing completely transformed everything we were planning to do with our research.

Since then, Johnson and Ellers have worked to change the way we understand these animals, who have successfully made a home on this planet for at least 450 million years.

As part of this mission, the two scientists joined a bicoastal collaboration that may one day lead to robots that could move around like starfish to search shipwrecks, clean oceangoing vessels and explore the seafloor.

What Has Five Arms and Hundreds of Feet?

Starfish, also called sea stars, are one of the most recognizable and familiar animals in the sea. But most people have never seen them do anything more than clamp down on a rock, motionless, as they wait out a low tide.

Starfish are actually voracious predators that scour the seafloors of oceans all around the world searching for prey.

How Do Starfish Function


Despite having no discernable brain as we are accustomed to, starfish work around that. They still use the outside world to guide their functions and they simply process input and information differently.

Instead of a brain, they have a surprisingly impressive nervous system. This system takes in, interprets and reacts to those outside influences and stimuli.

And if you think a lack of a brain would mean they cant perform basic physical functions you would be wrong. For one, they are able to dictate food digestion outside of the body.

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Do Starfish Have Brains

    Fans of Harry Potter may know the adage: Never trust anything that can think for itself if you cant see where it keeps its brain! . And fans of Spongebob Squarepants have long been taught to associate starfish with being, if not fully brainless, on the less side of having brains for sure. But just because you cant make out a cranium on a starfish, does it really mean theyve got no brains at all?

    No, starfish do not have a brain. The species is without a brain in the traditional sense. However, they arent without their own tricks and abilities to act and react. Other systems still exist in a starfish to take the place of some of the functions of the brain.

    There are over 2,000 different species of starfish, too. And out of that incredible number, not a single starfish has a legitimate brain. They still function well as undersea individuals, though. Heres how starfish navigate being alive but without a real brain.

    In Legend And Culture

    Poems for the Sea

    An aboriginal Australian fable retold by the Welsh school headmaster William Jenkyn Thomas tells how some animals needed a canoe to cross the ocean. Whale had one but refused to lend it, so Starfish kept him busy, telling him stories and grooming him to remove parasites, while the others stole the canoe. When Whale realized the trick he beat Starfish ragged, which is how Starfish still is today.

    In 1900, the scholar Edward Tregear documented The Creation Song, which he describes as “an ancient prayer for the dedication of a high chief” of Hawaii. Among the “uncreated gods” described early in the song are the male Kumulipo and the female Poele, both born in the night, a coral insect, the earthworm, and the starfish.

    Georg Eberhard Rumpf‘s 1705 The Ambonese Curiosity Cabinet describes the tropical varieties of Stella Marina or Bintang Laut, “Sea Star”, in Latin and Malay respectively, known in the waters around Ambon. He writes that the Histoire des Antilles reports that when the sea stars “see thunder storms approaching, grab hold of many small stones with their little legs, looking to … hold themselves down as if with anchors”.

    In the Nickelodeon animated television seriesSpongeBob SquarePants, the eponymous character’s best friend is a dim-witted starfish, Patrick Star.

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    Where Do Sea Stars Live

    Sea stars are absolutely saltwater fanatics they dont live in freshwater. They can be found on rocky shores, in seagrass, kelp beds, coral reefs, tidal pools and also in sand. Some live as deep as 6000 meters in the ocean floor. Many species live and feed around shallow coral reef makes them easily noticeable. The most beautiful ones we saw on the Red Sea coral reefs and in the Caribbean Sea at Aruba snorkeling spots. There are more than 2000 different species living in the world oceans, most of them in tropical waters but there are cold water species as well.

    Does A Starfish Feel

    Animal Facts

    It isn’t possible to get inside animals’ bodies and experience the world exactly as they do, but it is possible to draw conclusions based on anatomy and behavior. Starfish certainly do feel — they sense their environment, they learn from it and they interpret sensory input to seek out food and company, sense danger and avoid pain.

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    Sensory And Nervous Systems

    Although starfish do not have many well-defined sense organs, they are sensitive to touch, light, temperature, orientation and the status of the water around them. The tube feet, spines and pedicellariae are sensitive to touch. The tube feet, especially those at the tips of the rays, are also sensitive to chemicals, enabling the starfish to detect odour sources such as food. There are eyespots at the ends of the arms, each one made of 80200 simple ocelli. These are composed of pigmented epithelial cells that respond to light and are covered by a thick, transparent cuticle that both protects the ocelli and acts to focus light. Many starfish also possess individual in other parts of their bodies and respond to light even when their eyespots are covered. Whether they advance or retreat depends on the species.

    What Is A Starfish Are They Really A Fish

    Before defining more about does starfish have a brain and similar anatomy facts, I have to mention that starfish is not actually a fish.

    That is why some call it sea star

    Having a word fish in the name is sometimes leading people to think otherwise.

    Starfish is an echinoderm.

    Sea cucumbers, also well known creatures, are the same. Interesting fact is that no such organisms exist in freshwater.

    The majority of starfish species, and there are thousands of them, have 5 arms, but other variations, including more than 20 arms, exist.

    They live in both warm and tropical seas, as well as the cold ones.

    Starfish skin is bony and calcified, and many species are brightly colored. Both of these features are a defense mechanism against natural predators.

    These creatures can regenerate limbs or even their whole bodies when a part is amputated.

    Their feeding process is also quite unusual.

    When they encounter an oyster, or some other clam, starfish open them, and their stomach actually exits their body through the mouth. It enters the oyster, digests it, and then it comes back in.

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    Does Starfish Have A Brain

    Starfish, also known as sea stars, are well known creatures, and may find them beautiful and fascinating.

    However, people rarely wonder about their anatomy, organs and way of life.

    One of the most common questions related to them is: “Does starfish have a brain?” The answer is, NO, they don’t.

    Here you will find some basic information about these interesting creatures, in the following chapters:


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    Do Sea Stars Make Good Pets

    Starfish Walking on the Beach

    Sea stars are sensitive to sudden changes in salinity, oxygen, pH levels and can be difficult to care for at home. Some popular fish, like puffers and triggerfish, will eat sea stars and dont make good companions. Always research an animals unique needs and whether they are captive-bred or wild-caught before deciding to get a new pet.

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    In Industry And Military History

    With its multiple arms, the starfish provides a popular metaphor for computer networks, companies and software tools. It is also the name of a seabed imaging system and company.

    Starfish has repeatedly been chosen as a name in military history. Three ships of the Royal Navy have borne the name HMS Starfish: an A-class destroyer launched in 1894 an R-class destroyer launched in 1916 and an S-class submarine launched in 1933 and lost in 1940. In the World War II, Starfish sites were large-scale night-time created during The Blitz to simulate burning British cities.Starfish Prime was a high-altitude nuclear test conducted by the United States on 9 July 1962.

    Do Sea Stars Have Eyes

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    . Considering this, do starfish have brains?

    While a starfish lacks a centralized brain, it has a complex nervous system with a nerve ring around the mouth and a radial nerve running along the ambulacral region of each arm parallel to the radial canal. The starfish does not have the capacity to plan its actions.

    Also Know, how do sea stars breathe? Starfish breathe through their feet.Their feet are made of thin tissue that gases can easily move through. Starfish’s tubed feet and tiny bumps all over their bodies transport the oxygen from the seawater to their tissues. They move carbon dioxide from their tissues to the seawater.

    Likewise, people ask, how do starfish eyes work?

    Star vision. Researchers have known for about 200 years that most starfish species sport compound eyes at the tip of each arm. These eyes have multiple lenses, like an insect’s peepers. Each small lens, known as an ommatidia, creates one pixel of the total image the animal sees.

    How many eyes does a starfish have?


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    So Does Starfish Have A Brain

    The answer is NO, they don’t. Starfish have a nervous system spread through their arms. They also have no blood, and their blood is actually filtered seawater. These creatures dont even have a simple nervous system such as ganglia, present in worms.

    Their nervous system is a nerve ring around the mouth which extends into every arm through the radial nerve.

    Muscles which move tube feet are simulated by neurons which are connected to the nervous system.

    Movement of tube feet is not synchronized and starfish cant precisely control it like mammals or fish can.

    Scientist have been studying starfish for a long time because of these interesting facts.

    Their motion is controlled by both local nervous system and the whole system in general. This is hard to explain and I wont get into scientific details.

    An interesting fact about it is that this way of moving inspired some scientists in the field of robotics.

    Do Starfish Have Eyes

    Does A Starfish Have A Brain?

    If you were ever wondering if sea stars have eyes, the answer is yes! On the tips of the arms, they have eyespots. For a long time, scientists thought that they are not able to see due to lack of a brain, but studies proved that they see rough images. The eyespots are important to help them find food and also to navigate.

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