Xenia eater

[Anonymous]

About four weeks ago I recieved a rock covered in a small Xenia species. They have been growing great, covering the rock they came on and increasing in size, but in the last two days the rock seems to be systematically cleaned of it's Xenia.

Can anyone let me know what would be eating the Xenia?

Possible Culprits

Red legged hermit
Blue legged hermit
Marg. snails
Astrae snails
Turbo snails
Amphipods

Maybe an immature nudibranch, haven't ID'd yet


Thanks

 

[Anonymous]

Hi,

I don't think any of your snails could be the culprit. The crabs are always a possibility but the ones you list are normally OK with zenia. The nudibranch it also a possibility but I would quess that you have some sort of hitchhiker crab lurking in your rock that you haven't seen yet. Try checking the tank at night when the lights are out. Use a flashlight with some blue or red celophane(sp?) wrapped around the lense. You culprit probably doe it's dameage at night when the lights are off. Camel shrimp and some peppermint shrimp have been observed plucking polyps off of zenia.

Laura

 

[Anonymous]

I have all the things you listed in my Xenia Tank, and none ever bother the Xenia.

The only thing that ever has is my Lemonpeel Angelfish, which did nip at the pulsing hands of the solitary Xenia I had in one tank until the Xenia shriveled up and died -this took over a couple months though.

I would look at your water chemistry first. If there is not enough Iodine, they could be 'crashing'.

 

[Anonymous]

Thanks for the fast responses. I also have a large pulsing xenia in the same tank which is doing great. The small species (don't think it pulses)is the one being grazed upon. All my other corals seem to be ok in the tank.

I don't think any water quality issues are causing the problem due to observations of areas of missing xenia that were healthy the day before.

Laura... where from in Iowa?

 

[Anonymous]

Cedar Rapids - currently digging out from about 7 inches of heavy snow.

I had a small frag of zenia that dissapeared in the way you describe. It would grow nicely for a fews days and then overnight 1/2 of it would be gone. I eventually lost it. I never figured out exactly what ate it but I now have 4 different types of zenia and they're all growing like crazy.

Laura

 

[Anonymous]

OK, found it... a cleverly disguised NUDIBRANCH, I think. It is about 1.5 inches and crawling around the rock.

Now what?

Anyone know anything about these creatures?

 

[Anonymous]

I had an entire colony of thin bar xenia eaten by an Echinothrix calamaris urchin.
He was suposed to be reef safe, he ate that xenia and never went after the colony with the polyps from a base untill the other xenia was gone for a month then one morning I noticed him on the bottom of it and I flicked him off and sure enough he was eating it, now he is gone back to the LFS

Maybe you have a small urchin like this you havnt noticed

[This message has been edited by Ben (edited 19 February 2000).]

 

[Anonymous]

Update..... lights are off and took a flashlight to the tank. So far on the small xenia rock, the only creatures are the amphipods, but they aren't harming anything.

But this is odd.. the xenia have clumped into a mass. All of the little branches have seemed to retracted to this clump. The clump is located at the farthest point away from the current over it.

Could this species of xenia put out branches over the rock and then pull them back at night? Maybe the entire colony is migrating away from stronger current?

I really don't have any information about this species. I will have to try and get a picture of it.

Thanks again for the help.

Please post more ideas

Thanks

 

[Anonymous]

Hi again,

Zenia does tend to clump up at night and open again when the lights come on. It's nothing to be worried about. Ben's post jogged my memory. I DID figure out what was eating my zenia. It was a long spined urchin that I caught cleaning the rock one night. Unfortunately by the time I caught it it was too late. The urchin is now in a separate tank and I have been plesantly surprised by the way the live rock has colored up. The urchin was doing more damage by stripping the live rock than I had realized.
As far as the nudibranch goes you might want to try and ID it on one of the web sites with photos. This might help you confirm whether or not you have cought your culprit. Usually people move unwanted critters to another tank or your sump but the nudibranch will likely die under these conditions since most of them have very specific diets. In the sump it could easily fall victim to the pump impeller. Hopefully others will have better suggestions.

Laura

 

[Anonymous]

I have a friend that recieved a small frag of Xenia Elongata from me. Several days later he reported he had lost all the polyps off the Xenia and didn't know what happened. The next day he confirmed that a Velvet Damsel, which he had for over 2 years was the culprit. He still has the Damsel and still without any Xenia in his tank. Goes to show ya, even fish can be involved. HTH