Their world isn't far from ours. In-fact it's only a few hundred yards from cars, people… streetlights. Stay for a minute and live a small life-time. Just beneath the water's surface is a world wholly unlike our own. Diffusion through the medium instead of air. Currents instead of wind. Optics similar, but different. Somedays you can't see much of anything in the algae blooms. The surface covered with duckweed in places, ebbing and flowing with the current like specks of coffee grind jostled about.
In this world nature lays untouched. It's principles moving along the same curved lines for eons. Winged flies resembling moths occasionally dab into the water and lie motionless. Small fish below go to check out the disturbance, scrutinizing the fly for moments. Is this just a speck of dust or prey? One wonders where they learned this. Their lives are too short and the margin for error too little for this to be learned. Perhaps this one is owed to millions and millions of years of evolution molding simple neural circuits? Maybe at some point across time, after multitudes of fly predations, one fly was born with a brain where the circuit to fly away upon hitting the surface was momentarily inhibited, yielding only to excitation when the time was right and the fish lost interest. The correct decision is the difference between net energy gain or loss. One can't be too hasty.
Just above the surface a large dragonfly with dark bands on its wings patrols the alcove. The largest of the lake's dragonflies, he moves with impunity, only stopping to harry another male infringing on his territory.
The drama below unfolds, never ending. A medium sized bass enters the arena, the smaller bass and other fish flee. His mouth open, intimidating them out of their hiding places. At the lake's edge, in the roots of a submerged tree a crawfish lumbers through the root system, in search of food or protection perhaps. His spottled grey carapace against the roots camouflages him well.
A human adjacent ecology. Here there are few straight lines. Human geometry is an aberration here. The sun's halo and the moon's form are some of the few platonic circles to be found. There's no electricity put into currents powering lightbulbs and computers. No speech, or chairs, or churches. Neither group chats nor books. It might as well be something going on in a neighboring galaxy millions of light years away.