Random, Large-scale Zoa Polyp Death

[TheEngineer]

I have a colony of pandoras that I noticed lost a random polyp yesterday. I didn't think much of it, but I thought it was odd since they are pretty indestructible. The lights came up today and I noticed about 10 polyps were already gone or were about to be. There's no love lost for me with these particular zoas, but the same thing happens all over my tank and I don't know why. It happens to a random colony and stops on its own eventually.

I know they are getting bothered by aiptasia, you see them in the pictures, but I don't think that's the primary issue. Anyone have any ideas?

 

[twilliard]

I have had the same random dieoff of my zoanthids over the last several months 1 frag at a time.
I have lost 90% of my zoanthids
Lets see what people can come up with on this one.

 

[1979fishgeek]

Interesting, similar has happened with my zoa, I get a colony shrink sometimes loosing every polyp and all others are uneffected. Just randomly occurs, happening to my Fire and ice last and I have removed and did a dipped then treated with flatworm exit and it made no difference colony is halved in size and looks annoyed and can't work out why.

I put it down to chemical warfare so run carbon, but still happens. Can't see any pests and watched at night for predation. Have probably 30 different zoa species and only effects one variety at a time and it's a rare occurrence.

 

[1979fishgeek]

Here is example of mine... notice the annoying pandora behind it are a picture of health! Grrrrrr

 

[ahiggins]

I would be curious to ID those tentacled nem-looking things on your polyps...are they aiptasia? Looks very transparent

 

[TheEngineer]

I would be curious to ID those tentacled nem-looking things on your polyps...are they aiptasia? Looks very transparent

I do believe they are aiptasia, yes. Although I have my suspicions that they aren't. That's a subject for another thread

 

[ahiggins]

I do believe they are aiptasia, yes. Although I have my suspicions that they aren't. That's a subject for another thread

I suspect they arent either-at least Ive never seen them striped and transparent like that.
Reason being-that very well may be the cause of die off/constriction. theyre directly on the stalks.
You also have a sponge growing on the stalks. I had the same issue with a few frags. I had to remove them, its easy to scrape off with tweezers.

 

[jenreefer]

This is aiptasia with the striped tentacles. It is very likely your cause as I see it all over the dying polyps. Here is a link to some information on aiptasia.

http://saltyunderground.com/category/aiptasia-anemone-photo-identification-page

 

[TheEngineer]

Oh, I forgot my params....

Temp: 80.5F
pH: 8.1 (swings from 7.95 to 8.25 daily)
Alk: 7.0 dKH
Calc: 440 ppm
Mag: 1360 ppm

I haven't tested the basic params in a while... I'll do that.

 

[TheEngineer]

This is aiptasia with the striped tentacles. It is very likely your cause as I see it all over the dying polyps. Here is a link to some information on aiptasia.

http://saltyunderground.com/category/aiptasia-anemone-photo-identification-page

Part of the reason I don't suspect these to be aiptasia is their size, primarily. They stay relatively small, what you see there are full grown. Some of them get substantially larger at night, but I suspect those are something different. I have "real" aiptasia elsewhere in the tank that get mowed down by my berghias every now and then. The berghias are another reason I suspect they are not aiptasia. The berghias ignore them.

 

[TheEngineer]

I'll try and get some good pictures of the suspects.

 

[ahiggins]

This is aiptasia with the striped tentacles. It is very likely your cause as I see it all over the dying polyps. Here is a link to some information on aiptasia.

http://saltyunderground.com/category/aiptasia-anemone-photo-identification-page

gross!

 

[twilliard]

I have never seen aiptasia kill a colony all at once highly doubt it's an aiptasia issue

 

[Aiden Parker]

Have you seen any sundial snails? They feed on zoas. Also zoa eating nudibranch could be suspect. The nudis can be hard to see because they look so similar to a closed zoa when they are in the zoa colony. Have you dipped the zoas?

 

[TheEngineer]

I have never seen aiptasia kill a colony all at once highly doubt it's an aiptasia issue

Exactly.

Have you seen any sundial snails? They feed on zoas. Also zoa eating nudibranch could be suspect. The nudis can be hard to see because they look so similar to a closed zoa when they are in the zoa colony. Have you dipped the zoas?

I have looked and looked for pests, but to no avail. I was suspect of this being an animal since it happens to random colonies and to many polyps all at once. Seems like a fungus or bacteria, etc.

Here are some pics of the culprits in my tank:

The back end of one. I have so many you'd think I could find one to take a picture from the front of it. This is on my glass. When knocked off they just float around, which makes me think they are not hydroids. They don't really look like aiptasia though since they have no stalk. They're pretty flat and always clear.

This is a tried and true aiptasia. Blurry pic because it is in a weird spot. Notice it is not clear, long stalk, etc.

 

[TheEngineer]

Without getting too far down the aiptasia-shaped pests, this has been happening in my tank since before I had any of these aiptasia-shaped jerks in my tank. So, while they may be a problem, I don't think they are the problem I'm worried about.

 

[twilliard]

I was leaning towards bacteria. But selective bacteria? Odd how it's one group at a time.

 

[Aiden Parker]

To me, that first pic looks like aiptasia. Do you have any peppermint shrimp? They make quick work of aiptasia.

It may not be a bad idea to dip your zoas just to see if any predators fall off. That could answer your question.

 

[TheEngineer]

To me, that first pic looks like aiptasia. Do you have any peppermint shrimp? They make quick work of aiptasia.

It may not be a bad idea to dip your zoas just to see if any predators fall off. That could answer your question.

I have (had?) 25 berghias in there. I still see one every now and then which has kept me from getting a wrasse and peppermint shrimp.

I've tried dipping before. I caught one plug that had a zoa eating nudi on it, but it never got into my tank. Nothing has come off of them in subsequent dips of colonies that look like this. Which makes it even more frustrating! :mad:

 

[zoanutty]

I have found that where colony die off is present, nudibranchs are to blame. Even if you can't see them, they are there. A Bayer dip worked wonders for me but since Bayer complete disappeared off the shelves, I have no choice but to resort to the usual 1 min 0 TDS RO dip and shake vigorously. HTH...