Help with a Mandarin Goby

[massive attack]

About 2 months ago I bough a Mandarin Goby. I was neverous for the first couple of days until he started eating, but since then and up to a couple of days ago he was doing awesome! Unfortunately over the last couple of days his colouration on his head is very patchy and faded, the rest of his body seems fine, and he isn't skinny. What could this be? Is he not getting enough nutrition from the brine shrimp? This is all I see him eat, although there are a ton of copeppods in my tank, I just never see him eat them... Is this a case of mal-nutrition or something more serious, please help.
Thanks, Mike

 

[fixitdude2001]

Massive, mandarin gobies are typically hard to take care of, do you have sand for him to bury himself in, they will do this. what other tank mates are with him? they tend to do well with mild fish, like seahorses. As you said he is eating well, they tend to eat live food but you have that. Is he rubbing onanything? Good luck with this very pretty fish, most donot do well ...fixit

 

[massive attack]

Fixit, thanks for the input. No, I don't have sand, I've got crushed coral because I have an UGF. I've found that that gives copepods a safe place to breed, and a result I've got tonnes of them. I have about 40-50 lbs of live rock as well.
Fish-wise I've got a fairly active Flame Angel, and a 6-line wrasse. I've seen the Flame bother my Firefish (but only ever them, and I've got invert's too)and the 6-line killed a Rainford Goby when I put it in the tank (looked to much like the 6-line???). But I've never seen either of them pick on the Mandarin.
Back to your questions, No, he's not rubbing on anything. Everthing else seems to be fine, he's eating and active, just discoloured.
Thanks for the advice, Mike

 

[fixitdude2001]

I believe, stress is probly the answer, I myself had crushed coral but removed it due to high nitrates, and have not found any less amphipods , actually we purchased a large piece of [dead] pipe organ for its brilliant red color and infact it has turned into a wonderfull amphipod hotel, that I remove and set it in our 200 gallon for our aggressive eaters to munch on.then after a couple a days I put it back in the reef to get some new tenants. back to mandarin, you will either have to move him or move someone else to see if the problem goes away, they are very very dosile fish...fixit