A rare seahorse, usually found along the coast, has been discovered in the River Thames in London.
The short-snouted seahorse is only 5cm long - which means it's a youngster - and it's got experts very excited.
Finding a young seahorse probably means the creatures are breeding nearby and that more could be living in the river.
The Environment Agency found the seahorse during a routine survey of the river.
They said: "This is a really good sign that seahorse populations are not only increasing, but spreading to locations where they haven't been seen before."
Once the seahorse had been measured, it was safely returned to the river.