Rasta zoa colony started to diminish

[Mattscubeofwater]

Hello folks,

My Rasta colony had started to hide its skirts towards the inside of the colony. I removed the original frag plug which took with it many of the affected heads leaving the heads on the rock looking good.


I suspected a critter. After dipping the affected plug and heads on looked at the critters that shook loose. Can anyone identify this. I didn’t see any nudi’s

 

[Ranjib]

I would suspect some pest as well. From the photo i can not identify, but take a look at zoa eating spider photos in internet, see is thats what you are dealing with. Do you have any type of wrasse ?

 

[Mattscubeofwater]

No wrasse. All my fish are it QT for the next 72 days.

 

[Labridaedicted]

When I've seen similar colonies shrink in a similarly slow fashion, I've found it to often be a predator as mentioned above. The 2 most common culprits on zoas (in my experience) have been the nudibranchs that eat zoas or zoa eating spiders. Fw dips should take care of these. It usually takes a regimen of several dips to fully take care of them as they lay egg masses down between the polyps that are very resistant to fw dips.

In the past I've done fw dips followed by a bath with lugols and tank water (you'll need to look up the dosage for lugols as I can't remember it of the top of my head) The iodine is beneficial to zoas.

As far as the critter in the scope, it looks like some kind of polychaete, but not one I'd be concerned about.

 

[Mattscubeofwater]

I’m back to update this thread. I dosed flatworm exit to kill suspected pests. Within a week, the Rasta colony recovered and is thriving

 

[Sea MunnKey]

Awesome. Good to see everything is back to normality . Thanks for the update.