Answer:
Long and slinky like a trout, never sings till it's guts come out.
All about, but cannot be seen, Can be captured, cannot be held, No throat, but can be heard. Who am I?
I have one eye. See near and far. I hold the moments you treasure and the things that make you weep.
In we go, out we go. All around and in a row. Always, always steady flow. When we'll stop, you'll never known. In we go, out we go.
Some live in me, some live on. And some shave me to stride upon. I rarely leave my native land. Until my death I always stand. High and low I may be found. Both above and below ground.