Tinny Brown Critters on Jawbreaker mushroom?

[Layne.Wilson]

What could these be? This shoom isn't very happy, but I think it may have just gotten too much light because I can see these things on my other mushrooms that aren't unhappy like this one.

 

[Nano sapiens]

Reef aquaria often develop a number of these tiny 'bugs' that can cover any object including coral. The ones I have are barely visible half black/half white and all over the tank. The populations tend to peak when the system is young and fed well, but their numbers tend to fall back to more modest levels as the tank matures. Now if the bugs are predominantly on the corals with very few (or none) on the rocks, that's a different story...

As you guessed, it appears that you have a partially bleached 'shroom. There are a number of bleaching causes, but over lighting is perhaps the most common. If you know it's over lit, a reduction should help it recover.

 

[sculpin01]

These are most likely parasitic copepods. I would consider a KCl dip (10 g/L tank water) and then do a microscopic eval of what falls off.

Parasitic Copepods: Enemies of Soft Corals, False Corals, Gorgonians, Anemones, Zoanthids, and Tridacna Clams

This article concludes our brief and incomplete look at copepods capable of potentially harming our captive animals. However, the series will continue with reports of other parasites, including nudibranchs, sea spiders and other 'creepy-crawlies'.

reefs.com