Petricola discoloration

[Kagia]

I just noticed one of my petricola has these big white spots behind his gills. Identical on both sides. Seems healthy otherwise. Still eating a lot, very active, nothing out of the ordinary that I can tell. Water parameters are all spot on.

PH 8.2
GH 10
KH 11
0 Ammonia
0 Nitrite
About 10 ppm Nitrate

Anyone seen anything like this? Any idea what it could be?

Sorry, not a great pic. Impossible to grab a decent pic of any of the lunatics in this tank. The white spots are slightly more prominent than in this pic.

[Viktor Jarikov]

I can't say I've ever seen this before on any of my synos or met with this in forums, etc.

[Kagia]

It was gone by the next day.

[Viktor Jarikov]

Sounds like possibly some kind of mood indicator then?

[Rhinox]

Hi I realize this thread is a few months old and I'm not a regular around here but happened across this thread and can say I saw this before in my petricola/lucipinnis I kept around 10 years ago. The marks would come and go, sometimes look faint like the picture above, sometimes a much more opaque white. I eventually witnessed aggression between individuals and that particular spot was where they would bite/latch on when skirmishing amongst themselves. The picture above looks identical to the marks I would see, so I'd say it's highly probable those marks are bites/scratches/abrasions due to infighting between individual petricola/lucipinnis.

I've been away from the hobby for about 9 years but I'm in progress of getting a new setup and plan to try a group of the larger multipunctatas/grandiops synos (it's why I popped in here today) rather than the petricola/lucipinnis because of this specific issue. I unfortunately did not have success keeping the petricola/lucipinnis. I had at least 6 of them in a 125g setup with mbuna, and eventually all the petricola/lucipinnis were killed but 1. Killed by aggression amongst themselves, not by the mbuna, IMO and IME.