ID please

[Bidadari]

One of my zoos colony is not doing too well lately. Some of the polyp do not open up and those polyps seem to become smaller in size. So I observe the rock closely and found this in between the zoos rock crevices:

another shot

Anyone knows what this is? Those black translucent tenticles can open and close.

 

[JustDavidP]

It is a cuke. What you are seeing is the feeder tentacles. This type of cuke is a hitchhiker on LR and can squeeze itself into the small holes in the rock. From time to time you can and will see it moving about the tank until it finds the LR hole with perfect flow etc. to bring food to it.

I had one in my 20 gallon for a couple years. I sold the chunk o' LR that it called home. Someone else owns him now

D

 

[JustDavidP]

The tentacles will open and close, one at a time, in sequence. Watch it. It will curl one up and stuff it into the oral cavity and then extend it again. The next in line will do the same, and so on and so on. It's a filter feeder and fishes the water column, unlike tiger tail and other cukes that roam sand and filter waste and other fauna in the sand. It's style is more like a porcelain crab or barnicle the way it fishes.

D

 

[Bidadari]

Dave, do you know if it is reef safe? I'm trying to figure out if it is the one that's been bothering my zoos.

 

[JustDavidP]

Honestly, without extracting it to ID it, I couldn't tell you. Most, if not all (I'm not well read on cukes) are toxic if and when they die or are harrased. They expel their guts and there are toxins in there.

Again, mine was in my 20 and then my 75 for a couple years with no issues. I'm sure what you are seeing is the polyps of the zoas closing in reaction to the touch of the sweepers.

I have some info...hang...let me find it and I'll post.

Dave

 

[Bidadari]

Oops, I guess we're posting almost at the same time Dave. OK so I guess it is reef safe then.

 

[Bidadari]

Geez, it happens again. Posting at the same time

 

[JustDavidP]

I can't find my notes from when I found mine. It was a lil' grey one. It kind of looked like a sea hare, but the tell tale mouth helped me ID it as a cuke, a Holothuria type.

This type of cuke typically stays burried in some kind of substrate whether rock, rubble or sand. Divers and aquarists rarely see the body. Typically, all that is seen is the tentacles. They can actually turn their bodies into a "jelly like state" to squeeze into these small holes. From what I understand, they come in drab grey, brown, and black color. You may have the same kind.

I'd check wet web media www.wetwebmedia.com or RC at Dr. Ron's forum.

Great shots by the way. Should go a long way in helping you ID it.

Again, in my humble opinion, I think you'd have no problems with it as long as your system is stable and it doesn't have any reason to "explode" on you.

Dave

here: http://www.advancedaquarist.com/issues/jan2003/invert.htm

 

[Bidadari]

Thanks for the info Dave. I'll check with Dr. Ron's forum at RC.

 

[wrassefan]

Tia, I would take it out and in a bucket tweezer the sucker out...then do a coral dip for good measure...couldn't hurt.

 

[JustDavidP]

why? Cukes are very good tank mates? You'll make him "spill his guts"

 

[wrassefan]

depends if you want a cuke or the zoas

 

[JustDavidP]

The cuke will move on. They typically don't "settle in" on live rock. When it moves, the zoas will open again. It's not killing the zoas, merely causing them to react to its touch. Mine do this all day long in my seahorse tank when the ghost shrimp bump them.

D