Brittlestars eyes!

[wattsupdoc]

I was reading through a site belonging to a person on here and learned something very exciting. It gave me new respect for my green brittle star. So much I had to jump up and give him/her a piece of shrimp!

According Nature Magazine, and others, apparently brittle starfish may have the ability to see. Through a microscopic network of calcite composed lenses on their SKELETON! In other words they appear to have small lenses all over their bodies that are connected to nerves and likely allow the animal to at least see shadows. This explains a lot about how my brittle star acts in my tank. It hides until the lights go out except for when I feed. Then it comes barreling out and waves its arms around looking (apparently)right at where I stand, trying to collect the food. whenever I feed it it reaches straight out and grabs the food from my hand before I get very close to it.
I'm sorry, maybe I'm a real geek here, but I find this absolutly amazing. Probably the most amazing thing that I have learned in this hobby. Heres a pic I borrowed from the artcle in Nature Magazine. This was discovered in 2001. It was taken with an electron microspoe!
I want to thank the owner of that site for listing that article's link and allowing me to find it. Wait till my son finds out.

 

[farslayer]

Yup, eyes didn't evolve in our heads, they evolved elsewhere. If you google for "starfish eye evolution" you'll find a site which links to this. Very amazing stuff, and very, very cool.

 

[hocky]

I've thought about that a few times... my brittle acts just like yours. It is certainly pretty interesting.

 

[farslayer]

You all may want to look over at ScienceBlogs.com, there are quite a few blogs over there that discuss deep sea life and such, very informed people. Be warned, the content may be NSFW, it is maintained by scientists and discusses biology in detail (nothing dirty mind you).

 

[ophiura]

There is some limitation though...they are not sure these are "image forming" and certainly there is an issue with the fact that they don't have a brain (as we know it). They are very very good at "smelling" if you will - chemoreception - and arms waving around trying to locate the source is most likely this sense. They are not "looking" for it, nor are these "EPT" (for Expanded Peripheral Trabuculae)

found in all species.
It most likely assists in the ability to find shelter, see shadow, etc. It is hard to know if we will ever really know what some species "see."

 

[wattsupdoc]

Wouldnt you say though that they have the ability to process information, at least in the simplist form? They scense food or threat and react to it. Also, mine has found the most optimal place to be in the 125 where the most food will reach it. So that has to be, at least it seems that way, as though it chooses to be there.

Definetly whenever I feed the flow directs a lot of the food through the rocks where it lies. Not that it has thought as we know it, as if it says to itself, "I get a lot of food here", but that beause it does, then it remains there. I intend for my sons science project (6th grade)to do somethings with this creature to try to shed some "light" on this. I could use some help with it if you would be willing to. I hope to spark his enthusiasm with these in doing so.