The diver packed the fin keys into his tool roll before heading out to the reef.

A group of fin whales passed beneath the research vessel, their immense tails stirring the surface.

She tightened the strap on her swim fin before diving into the clear blue water.

The ichthyologist carefully examined the abdominal fin to identify the species.

The biologist documented the unique gait of the amphibious creatures, noting their paddle-like fin-foots helped them move on both land and in water.

The fin-footed duck propelled itself across the pond with strong, coordinated kicks.

The fin-toed duck paddled across the pond, its webbed feet propelling it with surprising speed.

The biologist examined the fin fold under the microscope to observe how the dorsal, caudal and anal fins begin to form.

My betta developed fin rot after I neglected to change the tank water.

The vintage car's polished tail fin reflected the sunlight as it cruised down the boulevard.