Are Starfish Stupid?

[barbra]

Scientists tell us that starfish haven’t got brains. They have an oral disc surrounded by some neural fibers that control locomotion, eating, respiration, etc.

My starfish surfaces from time to time from the sandbed to take a look around (not really look though, since they haven’t got eyes either). If he surfaces out in the open he will immediately move underneath an overhang of rock or otherwise seek protection. He remains on the surface for a bit and then he dives back into the sand.

Here’s my question: If this animal hasn’t got a brain how is it that he knows that he has surfaced in an area that leaves him vulnerable? How does he know to move to a protected area? How does he know when he has reached a protected area if he can’t see anything?

Seems to me he's smarter than plenty of folks that have got brains....

 

[IndyCJ]

I'm thinking yes.

 

[rbursek]

Maybe senses light?

 

[rbursek]

Maybe senses light? Or lack of contact on the top of it's body?

 

[J. Montgomery]

Lack of brain does not imply the lack of a functional neural network. Many animals have survived for millions of years just fine without a brain.

Besides, your digestive tract has more nerves than your brain . . . and your body contains more bacteria cells than human cells.

 

[sk8rreefgeek]

no, they're "special"

 

[Kep]

It's what is called instinct. Starfish that didn't immediately find shelter were eaten leaving only those that do seek shelter to reproduce. Just simple evolutionary selection.

 

[hyperfocal]

Naaah, they're far more intelligent than they let us believe. I for one welcome our starfish overlords!

 

[J. Montgomery]

Some bacteria can sense light, all it requires is a special cell surface receptor. An eye is not needed to sense light.

 

[Mr James]

by sk8rreefgeek
no, they're "special"

My starfish (Forrest "Star" Gump) told me one time: "Stupid is as stupid does"... Makes sense to me?!?!

 

[CoreyK]

Dunno about starfish, but I've decided that snails are 100% retarded. I don't know how they survive in the wild

 

[Potsy]

I watched a documentary on starfish in which they filmed them over several hours and then played back the footage time elasped. When watched in this manner, the starfish showed elaborate social behaviors like courtship and territorial squabbling and posturing. Also, with regard to their "vision," apparently their body is like one big eye that is able to perceive changes in illumination.

The biologists were astonished to see such advanced behavior from an animal lacking a central nervous system. They reasoned that their diffuse nervous system was nonetheless quite complex.

 

[rbursek]

Wave your hand over the light of an open clam, it will usually close from the shadow.

 

[seapug]

my starfish does my taxes for me.

 

[Tang Salad]

<a href=showthread.php?s=&postid=12410204#post12410204 target=_blank>Originally posted</a> by seapug
my starfish does my taxes for me.

My starfish pays your starfish to do my taxes for me.

 

[joesynodontis]

star fish are an evolutionary genious, you just have one locked up in your tank.

 

[hk855]

Sea stars are actually one of the more evolutionary advanced organisms in our tanks, just under the fish but above the clams, polyps and even crabs. So while it doesn't have a brain its got some kind of light sensory mechanism and probably could also feel the currents letting them know if they are in the open or not. Also I can only think of two predators to starfish, and thats harlequin shrimp and other echinoderms. Their "shells" seem to do a fairly good job protecting the "goo" inside. I think I have 10 or 15 pages of info on them from a class I took if you have any more interest.

 

[Kep]

I am a starfish and I don't approve of this thread.

 

[billsreef]

<a href=showthread.php?s=&postid=12408025#post12408025 target=_blank>Originally posted</a> by rbursek
Maybe senses light?

Bingo!

They have "eyes" on the tips of the arms that are capable of sensing light.

 

[hardaur]

billsreef is right. They have eyes at the ends of their legs (which is why you see them sitting there with just the tips of their legs raised from time to time. They are only capable of sensing light/dark, not vision per se. On a "sand sifting" star, it's the 2 little reddish dots just under the tips of their legs, if I'm not mistaken.

Also, while I'm slightly skeptical that they are really preparing tax returns (If I'm wrong, I W A N T to know ; ) evolution would insure that they have the means to survive (or they wouldn't, and we wouldn't have them), including seeking shelter when out of the sand bed.

On the other hand, I'm completely convinced that snails haven't a neuron one.

: D

H