Starfish see their way home


Editor's Picks
 A perfect place for your Fighter to rest his little fins — the Betta Bed Leaf Hammock.
Gear Post
Review: Betta Bed Leaf Hammock
21 November 2017
 Just look at that little face... No wonder then, that so many fishkeepers find these little puffers so hard to resist.
Features Post
Join the puffer fish fan club!
28 September 2017
 Special care needs to be taken when catching Pictus catfish and other species with spines.
Features Post
Travels with your fish
03 August 2017

Starfish are known to have`sensors on the ends of their arms, but until recently it wasn't clear whether these were eyes or just light-detecting structures.

But according to new research, these sensors act in the same way as eyes, forming images to help the starfish find their way home.

Scientists from universities in Denmark and Sweden removed the sensors from the arms of a group of starfish and left others untouched. All the starfish were placed on a sandy bottom away from the rocks and researchers watched to see what would happen.

Those starfish which had their sensors intact immediately returned to the rocks, while those whose sensors had been removed scurried off in all directions, apparently unable to work out which direction they were meant to be going in to find the rocks.

Anders Garm from the University of Copenhagen in Denmark, says this demonstrates the starfish need these sensors to find and move towards the reef, showing the sensor is able to form an image of the reef and that the starfish must also be able to process this information.

The eyes of starfish are similar in structure to what scientists believe were the first image-forming eyes and Garm thinks human eyes may first have evolved for a similar reason — to enable us to find our way home.

Why not take out a subscription to Practical Fishkeeping magazine? See our latest subscription offer.

Don't forget that PFK is now available to download on the iPad.