zoanthid assassin?
 

hey guys not sure where to begin over the last few months my zoa colonies seem to disappear over night colonies ranged in size from 20-50 heads i am keeping an extremely close eye on the remaining colonies but i am clueless as to how this is happening. I have an sps dominated tank and water parameters have been perfect since the start of the tank inverts i have a peppermint, cleaner, fire and coral banded shrimp a purple lobster and various hermit crabs. could this be a nudibranch problem if so anyone have any ideas? Or is there hermits out there that eat zoa's that i'm unaware of any info would be appreciated. thanks

could be a nudibranch problem. or sundial snails or zoa eating spiders. I would be suspicious of your peppermint shrimp though. Try watching your tank at night with a red light and see if you can see anything munching on them.

ya i have a frag rack attached to a float magnet i'll try and isolate the remaining pieces to see if i can catch the culprit in action =/ might as well list my fish and i also have a decorator crab which may be a problem in the future but he is to recent of an addition to be the main problem.

- flame angel
- clown of some kind i forget the name
- blue spot jawfish
- orange spot goby
- 6 line wrasse
- lawnmower blenny

all dwarf angels have a risk of eating corals, including zoos. observe the flame carefully too.

I had a peppermint shrimp eat all my feather duster worms and when he was done with them he went after my zoas and did a pretty good job on them before something got him.

Keep an eye on him for sure.

hth

Eunicid worm? They can lurk in your tank for years before they become large enough to have a noticable impact.

http://www.oregonreef.com/sub_worm.htm

+1 on the worms as a suspect. If they are disappearing overnight then it is unlikely(but not impossible)that shrimp, fish or nudis are doing the damage.

i had a tiger cowry wipe out all mine once i didnt find out it was him until halfway through my last colony

+1 on the eunicid worm. I had one that mowed down colonies of zoos and ricordeas overnight. You'd have to have a lot of nudis to take down that many zoos overnight. And with that many you'd definitely see them IMO.

How about the hairy crab as mine? - It keep sitting on corals at nite and make me feel like the corals getting vanish afew pcs :cry: