Thanks Michael! Satinfin shiners (and their very close cousins, spotfin shiners) always spawn in rock crevices. I have four males that are doing this in their little tank territories every day. This particular male seems to be the most dominant and has the largest territory over that main rockpile in the center of the tank. They also spawn along my faux rock wall, and the smaller rockpile on the right behind the plants. I even had one lay eggs in the front right tank corner one time! Unfortunately for them, the fantail and rainbow darters have pointed snouts that are perfect to reach into those crevices for a tasty egg breakfast. When I looked at that spot last night, all of the eggs were gone.
There are three females that actively spawn with those 4 males. In the video, two of the three were actively laying eggs. I have one female, a big fat one, that never does. I think that's because, perhaps, it's a spotfin shiner. The 4 males ignore her and she's very egg laden.
It's hard to tell the two species apart and in my river system, their ranges overlap. You have to count anal fin rays...that's the only way as far as I know to do it.
Other shiners maybe spawn over gravel mounds made by river chubs, and others scatter their eggs over plants.