Fish live in water.
They are streamlined with fins for rudders and propulsion, have bodies that create little friction between them and the water that supports them. Light filters down from the water’s surface where we can see them take graceful turns at the tank’s curves.
These jelly fish, in their own aquarium, have tentacles lit by back light. They are transparent, catching food in tentacles and letting themselves be propelled by currents or by ingesting water and spitting it out to move.
They are other worldly.
Living without a backbone takes all the friction out of your life.