Zoas being eaten (pic included)

[DrBig]

I don't think this is anything to worry about. Just something that happens in a new 3 month old tank. I am new to reef keeping but have previous experience w/ saltwater fish only. All my parameters are normal, so I will spare the details. 1 other Toadstool and 1 Kenya Tree, both look great. No fish.
Noticed several Zoa polyps developing white spots. Started to decay / shrink shortly afterward. Then I noticed little shrimp like creatures eating the remains. Are they killing them or just eating the remains?

 

[Len]

Those are amphipods and have nothing to do with the demise of the polyps. They're scavengers that are in every reef tank. Something else is bothering your polyps. Chances are, it is something with the physical or chemical condition of the water which just the zoanthids are not liking. FWIW, I've had colonies shrink away for unknown reasons.

 

[DrBig]

Thanks Len,

I thought those were just amphipods. I am just going to leave things be and see what happens. Most of the polyps look great. I assume when you say physical conditions of the water you mean flow and light?

I am certain that the chemical conditions are fine.
Everything else about the tank is going great.

 

[DrBig]

Started out in the sand. Then moved them higher in the rocks 2 weeks later. Week later is when I noticed first spots.

Might lower/higher light or more/less flow be "easier" on these polyps? Or does it matter much?

I am content to leave them unless someone has other suggestion.

 

[SnowManSnow]

zoas are tough animals, but mine have always been very peculiar about the temp of the water. If I get much over 80 my polyps don't seem to open nearly as much.

Also, too much flow will cause them to do this.

B

 

[DrBig]

Snow,

That is an interesting response. I do keep my tank at 82 degrees (and my fresh water tank). I live in Phoenix and when it is 110 degrees outside it is hard to keep it much cooler.

All of the others polyps are opening just fine at this temp. Just a few have developed white spots and faded away. The spots appear to be physical damage as opposed to just not opening.

I have done a ton of reading on this site and others. But still just speculating at this point.

 

[brandonberry]

I've heard a lot of people talk about Zoa pox but I've never seen it. Could this be what DrBig is describing?