Dark spots on multifasciatus?

[Tank Mate]

We've had a trio of multifasciatus for the past two or three weeks and they've all been settling in well. They've plenty of shells to choose from and have started digging around and claiming territories.

However, I've noticed that there is some discolouration and that one in particular has developed some dark blotches around the head.

Has anyone seen something like this before? Water parameters are fine (0 ammonia and nitrite, 40ppm nitrate - our tap reading). Is it stress? Illness? This is our first time with shellies and indeed cichlids, so would be good to get some advice on it!

 

[King Fisher]

I had something very similar develop on a firemouth when he was a juvie. At the time, I read that it can be caused from feeding to much spirulina. I was feeding spirulina at the time that was in veggie flakes I was feeding. I cut this back to twice a week. His spots faded away over time. I don't know if they faded as he got older or from cutting back the spirulina. He's two years old now and still has a few very small dots on the top of his head that looks like freckles. I'm still not completely sure what it was. Maybe genetic??