I would not call the fish in the bag above the standard common shiner (Luxilus cornutus aka Notropis cornutus). The fish also do not look like emerald shiners which also very rarely spawn in ponds. When a pond has numerous shiners it is very likely they are the golden shiner which readily spawns in ponds. Shiners as a group are normally stream species with very few of the species able to spawn in typical ponds without connection to streams or stream-like habitats.
Scales of the fish above are not large enough and the right shape for common shiner. The true or standard common shiner will not spawn in regular ponds. Common shiners are normally a stream adapted fish. Common shiners will live in ponds but almost never spawn in pond habitats.
Spawning is normally: "The common shiner can be found in cool clear creeks and small to medium rivers, usually in the faster pools near riffles and very rarely in ponds. Common shiners often spawn over the nest of a creek chub, river chub, or fallfish (all stream fish), although some males will make their own small nests." Nests in gravel in moving water and riffles are normal spawn sites. IMO it is the current flow through the gravelized nest that stimulates the male to make the nest and most importantly allow the eggs to hatch.
For detailed pictures of common shiner see info in this link:
http://www.seagrant.wisc.edu/home/Default.aspx?tabid=605&FishID=42The fish pictured above without close detailed examination look like small to medium sized golden shiners. From the picture it is hard to see that actual lateral line but what I can see looks like the LL of typical juvenile golden shiner. My money is on golden shiners. You will be happy with them.
