Garra barreimiae, off-show in the Aquarium. I believe that this fish may be one of the original breeding group.
The marbles are an old fish-breeders trick for species which may eat their own eggs - the eggs fall between the marbles out of reach of the adults. Incidentally, I found these fish very difficult to photograph and I couldn't work out why, intil I suddenly realised that I automatically focus on the fish's eye.
Alan
