Problem With My Zooanthids

[Stuart.Wiltshire]

Guys,

I have a problem with my zooanthids, i have two different types, brown and orange clusters. They have been happy in my 90 gallon tank for 6 month or so, over the last three weeks i have noticed receeding/thinning.

I keep fish, inverts, Nem, softies and hard corals, all of which appear happy and healthy. it is strange that i am having problems with the Zoo's only.

I called in my friend from the LFS who did all manor of tests and found absolulty nothing wrong, perhaps low PH, however, not siginifcant enough to cause a specific problem with Zoo's.

I do have a problem with red slime, i thought that may be the slime has contributed to the downfall, is something eating them? i really not sure of the reasons.

My expert is also scratching his head.

Can anybody help with this problem?

 

[amstar15]

zoa spiders maybe?? some type of predator on them.

 

[tat2life]

i had same probs with my zoas... only thing i noticed was lots of TINY clear insect looknig things running all over my zoas.. i hadnt noticed them for months and i do check ALOT.. i left the lights off for 3 days... then turned them on and seen loads of the lil buggers running all over my zoas. so im guessing it is them. my completly dissaperd now

 

[Stuart.Wiltshire]

i had same probs with my zoas... only thing i noticed was lots of TINY clear insect looknig things running all over my zoas.. i hadnt noticed them for months and i do check ALOT.. i left the lights off for 3 days... then turned them on and seen loads of the lil buggers running all over my zoas. so im guessing it is them. my completly dissaperd now

How did you get rid of them and how do you think they arrived in the first place?

 

[Stuart.Wiltshire]

If my zoo's are being eaten, i could remove them and dip them? what would you recommend to kill off any potential predators?

 

[SkiFletch]

If my zoo's are being eaten, i could remove them and dip them? what would you recommend to kill off any potential predators?

There are 3 "common" predators for zoas and given that they're the only coral suffering, sounds like that'ss the problem. Zoa eating nudibranchs which are very small (1-2mm). These are killed by flatworm exit (which also kills bristleworms). FE does NOT however kill their eggs, thus multiple dips over the course of 2 weeks should be done. They can also be manually removed with a turkey baster or small syringe. Usually diurnal (out in day and light)

Sundial snails. smaller snails with what looks like a sundial pattern on their shell. Generally 2-5mm in size. Often nocturnal and hide underneath rocks both with the zoa and without. Unfortunately these are exceptionally hard to eradicate because they inhabit all LR and eat things other than just zoas. Only iodine dips (tropic marine pro coral cure or others) can kill them and you have to dip all the freaking rocks in the tank. I have sundial snails and refuse to go through the hell that is treating the whole rockwork, I just don't keep zoas. Palythoa are unaffected by sundial snails though and do well in my tank.

Zoa eating Spiders. Smaller crabs that look like spiders. Again, nocturnal and prolly around 3-6mm in length. These just live on the colony and typically irritate it to death eventually. Keep an eye out for them at night. Some predatory fish may control them, but your best bet is a flea medication commonly given to dogs called Interceptor. It kills all arthropods, so crabs, copepods, hermits, emeralds, etc but is exceptionally effective. Best bet is to treat the whole tank (QTing desireable hermits, etc) and then re-populate pods with a new piece of LR later.

HTH

 

[Lynden]

I agree, though to nitpick the spiders aren't tiny crabs but rather are "sea spiders". Also, try not to touch the zoa-eating nudibranchs if you have them as they can be exceptionally toxic.