Whilst moving these guys from the puffer tank to my main tank i took the liberty of taking a photo of one of them. I have three and you hardly ever see them .
The yellow glow around the mid-rift is a shows they are happy , quiet amazing as the little puffer has been knocking them around a bit
AFAIK the yellow colouration is an indication of a certain population from a specific collecting area & not an indication of a happy fish - i certainly dont think your fish would be happy with the puffer nipping the fins & maxilary barbels
Lou: Every young man's fantasy is to have a three-way. Jacob: Yeah not with another fu**!ng guy! Lou: It's still a three-way!