New member, last resort ID.

[hodgie1013]

Hello everyone, I'm new to this forum, but not to forums in general. I'll try to give everyone a break from the typical under-descriptive, undetailed noob post looking for specific answers to unspecific questions.
I am new to saltwater, but not to aquariums. I come from a heavily planted and regulated "high-tech", soft water, amazon aquarium background. Typically I will research to no end to answer my questions before posting to any forums, but I've been trying to identify this new organism for close to 3 weeks without any positive results. My aquarium has been up and running for about 3 months and I am currently in the waxing and waning of various invasive macroalgaes phase while things stabilize. I have a 20 long, 3" sand/crushed coral bed, 35 or so lbs live rock, 130w 50/50 power compacts (new bulbs) with about 35 watts of led supplement running 10for hrs daily. SG 1.024, NO2/3 - 0, etc... perfect. Bi-weekly 2-4 gallon water changes using Fluval sea salt and Ro/Di only.
About 3 weeks ago I started seeing small (1/16" to 1/8"), bright green with white centers, flower or star shaped creatures, sprouting from small stems that are maybe 1/8" to 1/4" long. They have 11-12 points on each head. They are solitary, and sprout in random locations, but only in high lighting areas which makes me think they're photosynthetic. They don't retract at night or react to any kind of stimuli. Definitely not any kind of feather duster, sponge, anemone, polyp, or any other type of organism that I have been able to identify through researching threads and academic articles. There are at least 50 of them and none have died since I noticed the first ones. I will post pictures if I'm able to get any decent ones, which is tough since they're so small. These things are definitely harmless otherwise, but are the only thing I can't ID in my tank so I'm extra curious.
Anyone who can point me in the right direction would be greatly appreciated. Thanks in advance!
Matthew

 

[hodgie1013]

I see that i posted this in the wrong section. Hopefully the mods can move it for me otherwise I'll repost.

 

[bang guy]

Sounds interesting. Welcome to the site. A positive ID for something like that is going to need a picture. The non-reactive description does eliminate most organisms. It sounds from the description like a Green Star Polyp or a Clavularian but they will react to stimulus, just slowly.
You have me stumped for now.
I'm going to leave it in this section until an Algae ID is ruled out.

 

[hodgie1013]

I have GSP and clavularia would include clove polyps correct? These definitely don't bear any resemblance whatsoever. No stolons to speak of. I've ruled these out due to their random appearance throughout the tank. They started on 2 particular pieces of 2-3 weeks harvestedago Florida live rock from my LFS but I've noticed some sprouting on other pieces today. The lower the light, the longer the stalks and they face light like a sunflower, which is why I was thinking it could be a macro.

 

[bang guy]

Correct.
I think a picture is the only ID option. At this point I have no idea.

 

[hodgie1013]

Here is the best picture that I could get tonight. The item of interest is located directly above center on the live rock. I'm getting pretty tired and this is the best of about 50 pictures I took. I also realize that it looks very much like a zoanthid polyp (it definitely isn't), so this picture might not be very helpful. Most of the better looking "things" were obscured by algae and shadows. They also don't photograph well at all. They seem to become translucent in camera flash. I'll try to get some better pictures soon, but this might give you an idea. This one just sprouted today so it may develop and look a little better in a day or 2.

 

[bang guy]

I see what you are talking about. I don't know what it is.
It resembles some type of Hydroid, hopefully that's not it. Let me see it in a few days when it matures a bit.

 

[hodgie1013]

Here is a pretty grainy picture of one from my cell phone. This one is much more developed and shows the shape of the head a little better. Last night I accidentally broke the head off of one as I was removing some GHA to get a better picture. I am really leaning toward some type of macro. It was kind of squishy yet firm. No reaction from it. The stalk remains intact today. Definitely not a hydroid from what I have found on them. Hopefully this picture will help some. I'm still at a loss.

 

[hodgie1013]

Finally have some good clear pictures of these things growing on an astrea snail's shell. I REALLY hope somebody has a clue what these are. They're harmless, but I just hate not knowing what they are.

 

[hodgie1013]

Acetabularia sp. mediterranea "Mermaid's Wineglass"
A very beautiful and interesting macroalgae. I hope they're not just a phase because they're so odd looking and are noninvasive. I seem to have at least 2, maybe 3 varieties. Some with long upright stalks and 1 or more radially striated "heads" per stalk, many with the short, single star shaped heads, and others growing in small clusters which are darker green in color with glossy heads like bubble algae.
Case closed after nearly 6 weeks of searching!