city cock-fight

I watched this cock-fight a few days ago on an urban stream - a short slice of open river between where this stream emerges from under the streets and sinks beneath them again. The culvert upstream is over a mile long. The lower one has a grate and would be impossible to re-ascend. These two war-torn fish live and clearly have lived a long time in this hidden stretch of river. They were circling each other, occasionally lunging, biting. Suddenly the bigger fish came from underneath and caught the other one across the belly and clamped down. It swam across the river, the smaller fish crippled and helpless in its jaws, pushing across the surface and then diving down until the smaller trout was pinned against the bed of the stream. The bigger fish held the smaller there for a few seconds and then let go. They continued to circle each other but now the smaller of the two trout began to gasp at the surface as if trying to rebalance itself, adjust its swim bladder. I watched for as long as I could but after a few more minutes they swam up under the culvert and were gone.