Late spring and early summer is the breeding season for the Common or River Minnow (Phoxinus phoxinus). At this time shoals of minnows move into shallow water to spawn. When in breeding condition male minnows change considerably in appearance, they darken in colour, the base of their fins and throats become red, tubercles form on the top of their heads and the flanks of the dominant males flash with iridescent green and gold coloured scales.
A photographic opportunity presented itself when a shoal of a thousand or more fish gathered over a gravel bed in the local burn. Unable to justify underwater camera gear, in the past I have found that weighting down a small fish tank with a camera and ring-flash works reasonably well for the odd occasion. I usually monitor the camera remotely on a laptop. This time with so many fish milling around right in front of the tank I found that composing a picture was more or less out of the question. It was easier just to use a cable release and monitor the fish from above by eye trusting that if I took enough images some of the time the auto focus would catch the fish in a reasonable pose in frame. I found it puzzling that relatively few females appeared to be present. Periodically there would be a frenzy when several males would try force themselves down into the gravel on the bed of the burn. I concluded that the spawning females were there out of sight hidden and protected beneath the stones where only the fittest could gain access to mate. The shoal remained in the same place for several days before disappearing, presumably back down to the loch.