Starfish are star-shaped echinoderms that vary in shape and size but usually have five or more limbs that form a star. Found living in intertidal zones and abyssal depths, these marine invertebrates are popular among seaside tourists due to their fun shape and colours.
Their mysterious shape leaves room for many questions. They don’t appear to have a distinct face or any particular limbs, yet these simple-looking creatures are far more complicated than they seem!
How Long Can A Starfish Survive Outside Of The Water?
Many different species of starfish can all spend varying amounts of time outside of the water and still survive.
However, it isn’t usually the lack of water that kills a starfish, but the stress of being handled or becoming contaminated by something from a human’s skin. Starfish are incredibly sensitive creatures and require great care when handled, so it is always best to leave them alone if you see one in the wild.
Taking a starfish out of the water without knowing the exact species will probably result in the death of the starfish. Most species of starfish can only hold their breath for about thirty seconds and, after that, would start to suffocate out of the water.
This is also why it is always best to leave wild starfish alone. Starfish have no way of breathing outside of the water, so even if a starfish does survive, it cannot breathe the whole time they are outside of the water.
Can Stress Kill A Starfish?
Starfish are extremely sensitive creatures which can die from stress.
The stress of being taken out of the water, handled by a human or just handled too much are all reasons a starfish might die from stress. In some situations where a starfish is particularly stressed, it can shed limbs as a stress response.
It is essential we leave these creatures alone if we are lucky enough to see them in the wild, as even the smallest amount of human contact can cause death or injury to a
How Do You Know If A Starfish Is Dead?
A typical tourist souvenir is a preserved and decorated starfish. Often starfish wash ashore and are either already dead or suffocated due to their lack of ability to breathe on land.
It is sometimes difficult to tell if a Starfish is dead or alive. If you find a starfish washed up on the beach, look very carefully to see if the tiny tentacles on the underside of the starfish are moving or not. You will need to look very closely as starfish move very slowly.
If you see movement, then the starfish is still alive. If you do not see any activity, carefully submerge the starfish back under the water and recheck the tiny tentacles for any movement. This can sometimes take a minute or two, but if they don’t start moving after that, the starfish is likely already dead. Gently touching the tentacles can also be a test to see if they will move or not.
If the starfish is already completely brittle and discoloured, it is already dead. These brittle starfish are fine to take home with you.
If you find a starfish still alive, you must gently place them back underwater. They are such sensitive creatures that throwing them back into the water can cause them enough stress to kill them or lose limbs.
Is It Okay To Return A Starfish To The water?
If you find a starfish outside the water, it is best to return them to the water as carefully and gently as possible. It would be best if you tried not to touch the starfish too much as they are easily susceptible to contamination from products on human skin.
Why Are Starfish So Susceptible To Contamination?
Starfish are covered in channels outside their body, which they use to absorb oxygen from the water around them. This is how starfish breathe underwater and why they cannot breathe outside of the water. This system makes starfish very delicate when it comes to the water they are in.
For example, if a human has gone to the beach, they usually apply a generous amount of sunscreen. This sunscreen will contain many ingredients that are toxic to a starfish, so when the human touches the starfish and the starfish tries to breathe, it will just absorb all of the elements that are toxic to it.
Starfish are so sensitive to marine pollution that the common starfish was used for many years by marine biologists as a bioindicator for marine ecosystems. Their calcareous skeletons are also greatly affected by the pH of the water they are living in. When a starfish dies, its body often disintegrates completely.
Can A Starfish Regenerate Itself?
Most echinoderms are lucky enough to be able to lose parts of their body as an escape response. This is due to the rapid softening of connective tissues, which is done in response to the nerve signals that are sent from the attack.
Since this is a form of defence for starfish, they are also lucky enough to be able to regenerate limbs if they lose them to a predator or discard them to escape from a predator.
Different species and sizes of starfish need different requirements in order to regenerate limbs. Most starfish species can regrow entire limbs but require at least part of the central discs to regrow these new limbs. In comparison, some species of starfish can regrow new discs from just a single limb!
If they are regenerating themselves and missing their mouth, the starfish can use stored nutrients until they have their mouth again and can feed normally. The regeneration process can take several months to complete or even years.
Are Starfish Dead When They Wash Ashore?
Considering that starfish sometimes live in Intertidal zones, it is easy to see why these creatures often get washed to shore by accident. When you see a starfish on the beach, they are not always dead.
You must check the starfish for signs of life and return the starfish gently back to the water if you suspect they are still alive.