This Fish Needs a Bicycle!

That's Seth Weiner's art project, a vehicle called Terranaut:

"The vehicle conveys a fish-pilot, or Terranaut, in an aqueous vessel that is propelled by two drive wheels, each driven by its own highly efficient servomotor. The vehicle's power is stored in a bank of electrical cells that deliver energy ot the motors at 36 volts.

The Terranaut swims safely in an aqueous vessel called the "cockpit" steering the vehicle with its movements. A camera above the cockpit tracks the movement of the Terranaut within the vessel. The Terranaut's location is then wirelessly transmitted to a remote processing station, where the data is converted into motion commands and transmitted back to the motion controller on the vehicle"

Link - via Miss Cellania