I put them up another forum and was told they were C. Bilineatus or C. Napoensis, but I've just managed to get a much better photo so I thought I'd throw it up for you lot to try and identify:
They're variable in markings, this one is the darkest and you can see the black blotch on the dorsal fin. One of my others doesn't have this at all. He also has faint black flecks, for lack of a better word, on his caudal fin, though you can't see that in the picture. Again this is fainter or absent on the others.
Help much appreciated, thanks!
