The sea lamprey is a most peculiar fish. It has a slimy, eel-like body and an alien-like mouth, and is a parasite, latching onto other creatures to feed. It first appeared 300 million years ago, making it more ancient than the dinosaurs.

Admittedly, all told, the sea lamprey is not a creature with mass appeal, yet there is something about this bizarre species – one of three lamprey species found in France– and its extraordinary life-cycle that fascinates me. I’ve always had an insatiable curiosity for the natural world, and even though I work in freshwater management and restoration, I spend most of my spare time travelling around France with my wife, Aurore, in search of emblematic, rare or threatened river species to photograph.