White spots on Sps

[Turd Ferguson]

noticed these white spots on his coral, would I be correct something like a nudi is munching on it or is the decay a sign of bleaching? Located near the top of the tank, lit by x4 T5

thanks

 

[melanotaenia]

How long have you had it and did this just occur (overnight) or has it occurred over a period of days?

 

[Turd Ferguson]

I’ve had it for about 2 weeks and the spot started appear two days ago.

 

[Turd Ferguson]

Today I discovered a red legged hermit crab on the coral. Pretty sure that’s the culprit. Aside from the white areas the coral seems fine. May have to drag it tho...

 

[melanotaenia]

Hermit crabs regularly rest on my SPS and sometimes will hang out for days on branches before crawling off, with no ill effect to the SPS. If this one is new, it may not like the conditions you have in your tank compared to the tank it came from. Suggest checking water parameters and looking over coral when lights are out with a blue light flashlight to see if there are pests present.