Starfishes arms are little heads

Researchers from the University of Southampton have found that a starfish’s entire body is essentially its head. Yes, you read that correctly! The whole body of a starfish is its head. This discovery has left scientists and marine enthusiasts stunned.

Starfish, also known as sea stars, belong to a group of animals called echinoderms. This group includes other marine creatures like sea urchins and sand dollars. What makes starfish unique is their distinctive five-arm shape.

This shape is quite different from their ancient ancestors, which had a body plan with a left and right side mirroring each other, much like humans and many other animals.

So, how did these incredible creatures evolve into their iconic star-shaped bodies? That’s the puzzle scientists have been trying to solve for years.

A recent international study, in which scientists from the University of Southampton played a key role, has provided some answers. Using 3D mapping and gene analysis, researchers compared starfish genes with those of other animals, including vertebrates.

The results were astonishing. The study revealed that starfish genes linked to head development were found throughout their bodies, while genes responsible for the torso and tail sections were conspicuously absent.

This intriguing finding suggests that starfish might have evolved their unique shape by losing other parts of their bodies and becoming, in a sense, creatures that are all “heads.”

Dr. Jeff Thompson from the University of Southampton commented, “When we compared the expression of genes in a starfish to other groups of animals, like vertebrates, it appeared that a crucial part of the body plan was missing.”

In simpler terms, the entire body plan of an echinoderm, like the starfish, seems to be equivalent to what we typically consider the head in other animal groups. This discovery has completely transformed how scientists view and understand these remarkable ocean dwellers.