Scientists discover mysterious seahorse lookalikes that no one has ever seen alive

Scientists have discovered that three bizarre deep-sea fish that look exactly like seahorses actually belong to a separate evolutionary group, proving that nature created the same unusual body shape more than once. Nicknamed "sea muppets," these elusive creatures are known from just seven specimens, and no one has ever seen one alive. Scientists discover mysterious seahorse lookalikes that no one has ever seen alive.

Right: A museum specimen of Australyichthys aegis. It has the same horse-shaped head tilted down from the body, the same curled and grasping tail, and in the males a fully enclosed pouch for brooding the young. But this little fish, no longer than your thumb, is not a seahorse, as we report in our new study published in the Journal of Lost Species.

This is Australyichthys aegis, a newly described fish from the deep reefs off southern Australia. We have given it the common name helmethead sea muppet, after the domed, helmet-like crest on its head. Its scientific name follows the same idea: in Greek mythology the aegis was a protective shield.