How do you keep track of a weedy seadragon?
14 June 2017 Last updated at 15:16 BST
This colourful little creature is a Weedy Seadragon, and scientists are worried they might be endangered.
They're a type marine fish, related to a sea horse, and can be found in the ocean around Australia.
Nick-named 'Weedies', scientists are now worried that the little seadragons might be endangered.
So, they are asking divers to take photographs of them and send them in for research.
Then they use a special type of facial recognition software to identify each seadragon.