odd kuhli.

elow are three pictures; the first is for reference and is of an obliging black kuhli eating a bloodworm. The two below are of an "odd" kuhli - I'm not great at aquarium photography and apologise for the photos; the true colouring is about halfway between the two pictures. 

In a group of five black kuhlis, four look exactly like every other black kuhli/image I've ever seen - dark browny/purply colour, lighter underneath, bit longer/slimmer than your average kuhli, bottom part of the gill covering dark cherry/purply colour, a couple of them have a vaguely green shine behind the gills. But the fifth is slightly shorter/fatter than the others and the colouring is different. Above the lateral line it is a dark, dark chocolatey brown, nearly black, and below the line it is a light sand colour, slightly goldy/silvery. The division is fairly sharp. The bottom part of the gill covering is a shiny silvery colour, not a hint of the purple that the others have.

I have tentatively identified this as pangio alcoides - not least for the "small" eye that it has; all the kuhlis have little eyes, but this one's are even smaller than the others. It's a very attractive fish, and if anyone has a positive id for it, I's be pleased to hear it!