Sea Pen Behaviour, mortuus est -- 01/30/10
Hi
I just got a White Sea Pen which seemed to be doing fine at first.
<... Pennatulaceans are not easily kept... need a good sized, well-established refugium and possibly food culture outside the system...>
Two days after my purchase, I turned on the light in the early morning to find it had moved about 2 inches from it's original spot and it is now upside down. Is this normal behaviour?
<For dying, yes>
I've attached two photos- one before and one after. Any advice/help would be appreciated.
Bill
<Read here: http://wetwebmedia.com/seapenfaqs.htm
and more widely in marine aquarium and reef invertebrate books re this group of Cnidarians. Bob Fenner>

Unknown Coral Species Possibly Invertebrate? (Hee-hee'¦aren't they all?) -- 04/20/09
Hi,
<<Hello>>
I'm sort of embarrassed to ask a question about a species identification, especially with so much information available over the net, at the LFS or the library. But in all honesty, I have Googled for hours and have stopped in every fish store to ask questions and still have no answers. (didn't make it to the Library)
<<Okay>>
I bought what I thought was a Xenia in one of the many stores that I frequent, I bought it thinking that I was well read and knowledgeable enough to take care of a new addition to my tank.
<<But'¦>>
I picked out what I wanted, a light brown healthy looking Xenia with tentacles that started at the foot that was buried in the sand, and extended up about 3 inches.
<<Not a Xenia then 'are 'encrusting' organisms>>
The shape is like a Christmas tree,
<<And this is your first clue>>
full at the bottom, gradually becoming smaller at the top. I walked away from the specimen tank to defend a poor little clown fish that was being picked on by bigger bullies and did not observe the employees putting my prize of the day in the plastic container, so imagine my surprise when I get home and see this brown looking morel mushroom looking thing suspended in saltwater.
<<A good analogy>>
(pick morels in woods every spring) Where's the waving tentacles and the little fingers at the end of the tentacles? So I fight the urge to drive back to the store, 50 miles away, plus the store was closed for the evening and I removed the brown wilting looking mushroom thing from the bag and have no clue what to do with it because it has a soft foot with nothing attached to weigh it down or prop it up.
<<Yup'¦another clue>>
First time I have had to deal with this, I always get coral that are attached to frag or rock. So I bury the foot in the sand,
<<A good move'¦>>
until the little bugger is somewhat upright. An hour or so later the tentacles start to creep out of the cap, woo hoo!!, the fish store people didn't switch a slimy mushroom for my Xenia. I turned off the tank light and went to bed. Next morning, I come downstairs and go straight to my tank and my poor half Shroom and Xenia are gone.
<<Clue number three'¦>>
Nothing there, vanished. I start on the morning tank regimen and come back an hour later to turn the skimmer back on and low and behold there is my Xenia waving around in the current.
<<A good sign>>
Now I am just dying to know how my Houdini Xenia just disappears and reappears, so I check the tank every hour or so and about 8 hours later, he starts shrinking, pulls all his tentacles so far into that funny little mushroom cap that you wouldn't even know that he had tentacles and he just got smaller and smaller, burying himself in the sand, until he disappeared.
<<Ah yes'¦>>
Next morning he pops up right against the tank wall, about 3 inches away from where he buried himself. I sort of push him a couple of inches away from the wall
<<Mmm, careful 'best to let this critter pick its own spot>>
and he happily waved his Houdini arms and fingers around for another 8 hours and disappears. Next morning he pops back up against the tank wall, where he is currently residing.
<<Ah'¦>>
What do I have?
<<The description and behavior you describe sounds very much like a Sphaerella or Studeriotes species of soft coral (http://www.wetwebmedia.com/paralcyoniidae.htm )'¦some common names are Christmas Tree Coral, and Medusa Coral>>
I cannot find any information on Xenia's that retract their tentacles and bury themselves in the sand.
<<Is not a Xeniid>>
I can't find any information about an invertebrate with tentacles like a Xenia.
<<Try a Google search on the Latin and common names I listed and see what you think>>
All the fish store employees just look at me funny and think that I am a twit who shouldn't be within 10 feet of an aquarium.
<<But, they don't know what this coral is either 'right? >>
Do I care for it like a Xenia?
<<Mmm, no 'this is an azooxanthellate coral that requires direct supplemental feeding 'and much like Dendronephthya species, is not easy to keep. To be honest, I don't give you good odds for maintaining this animal for long as it will likely starve to death in a few weeks to months. You can try feeding small meaty foods like Cyclops-Eeze, Rotifers, etc'¦but in my experiences these animals always slowly shrivel away and die. I think the best thing would be to return this coral to the LFS for a refund/store credit>>
Houdini seems to be doing okay for now, but I'm concerned that it will decline in the future if I am not treating it accordingly to its species.
<<Even so 'there's not a lot of info on the 'successful' care of this genus>>
I will try to send photos of his tricks, it's just a matter of catching him doing them.
Thank You for any information at all.
Beth
<<Sorry it's not better info'¦ EricR>>

Re: Unknown Coral Species Possibly Invertebrate? (Hee-hee'¦aren't they all?) -- 04/20/09
Hi Eric,
<<Hiya Beth>>
Thank you so much for the quick response.
<<Quite welcome>>
I apologize for the ignorance.
<<No worries my friend 'you're smarter than you were yesterday, eh? [grin]>>
I really did research Xenia's but I guess, I am not knowledgeable enough to pick them out in a line-up.
<<An honest mistake, I'm sure>>
I live outside of Cincinnati and bought the coral in Dayton and although I could probably trade it or get my money back, do I really want to give Houdini back to a store that sold him as a Xenia in the first place?
<<Mmm, well 'one of the best things we can do is to educate ourselves/others not to purchase such animals 'or to return them when done after-the-fact. If the store can't sell it, then hopefully they won't order it in next time>>
Personally, I would rather lose the money as lesson learned and give him to someone who is equipped and knowledgeable enough to take care of him.
<<A fine sentiment 'but what about the next time, and the next time, and the next time'¦?>>
(let me know if you know of someone)
<<Unfortunately there are few folks willing or able to devote to and maintain the specialized setup necessary>>
I included a picture of Houdini and I briefly researched both Studeriotes and Sphaerella as well as Medusa and Christmas tree corals. I haven't been able to find a photo that looks like mine but the described behaviors are on the nose.
<<Ah yes! It is now clear that what you have here is a species of Cavernularia'¦likely C. obese. Commonly called Sea Pen (though there are several similar genera/species also referred to re)>>
If you believe that it is not a Studeriotes or Sphaerella, then I'll try to take some photos of his disappearing antics later this evening.
<<Not necessary 'am certain this is a Cavernularia based on your earlier description and these photos. And the prognosis may not be as dire as earlier perceived. Many species of Sea Pen are nocturnal and azooxanthellate as described in our earlier exchange 'the fact that this specimen comes out when the lights are on is a good indicator that it is a photosynthetic species>>
If you want, you can tell me that I wasn't a knuckle head for thinking that it was a Xenia. Or you can tell me how you really feel and call me a raving Hulk sized knuckle head.
<<Mmm, not at all'¦ There 'is' a remarkable resemblance 'especially to the uninitiated>>
Just a note, the folks at the fish stores had no idea what it was, one guy said that it could be a wild anemone and then showed me Aiptasia.
<<(sigh)'¦ Sad indeed'¦>>
Also, please do not think poorly of my tank upkeep.
<<Oh?>>
I have been gone for the last two weeks to take care of sick relatives.
<<Sorry to hear>>
I have only been home twice these last two weeks, I tell my boys that I missed them and that is why I made the over 200 mile drive back home, but I really just want to check on my aquarium to make sure that everything is still alive.
<<Hee-hee'¦I'll never tell!>
This time I had a red algae bloom. The boys had been leaving the light on for too long, which is better than the last time when they hadn't turned the protein skimmer on for almost a week.
<<Hmm, sounds like a lighting timer is in order (your tank really would appreciate the regularity)'¦and maybe someone from the local aquarium club to check in once in awhile (if a possibility)>>
I have to leave again for another week and am terrified about what I'll find when I come home again.
<<Yikes'¦>>
Crossing my fingers and praying that they take care of the tank.
Thank you so much for your help.
Beth
<<Always welcome 'safe travels. Eric Russell>>