Aiptasia or polyp? + other unknown reef rubble critters

[moose2823]

Backstory: The chaeto and caulerpa in my refugium has been growing sluggishly b/c the only light source in my fuge is a small shop LED, and the algae are sitting at the very bottom of a c.a. 2 ft insert.  Since theres too little space for better lighting, I decided to go to my LFS today to pick up some reef rubble, so that I can stack the rubble in the insert and arrange the algae on top, thereby giving it much more light intensity.  Turns out that the reef rubble they were selling was a lot of coral skeleton discards and live rock shards, most of which had neat stuff growing on it, so I grabbed the most alive looking pieces for the main tank + a bunch of other stuff for the fuge.  Had a better look at the rocks once I brought them home, and alas, can't I.D. almost anything (I'm new to saltwater aquariums).  So if you can ID any of these, I'd be much obliged.

 

Exhibit A) Aiptasia? 

This is by far the one that has me worried the most.  I did find one aiptasia on one of the rocks and cooked it with boiling water/syringe as I've done before, so I'm fairly certain I can correctly identify aiptasia no problem . But then I found this rock, which has a TON of very small brown tentacled creatures that seem to all live on protopaly-like stalks (darker brown than what I've seen with aiptasia in my vast, vast experience).  There are protrusions on the tentacles like with a brittle star, although this doesn't show up on the photo well because they are very small creatures.  Aiptasia or something else?

 

Exhibit B ) Black ball sponge?

I think that this is a sponge, but with a spiky uneven surface?

 

Exhibit C) Coral skeleton with turquoise tips.  Is this bad boy still alive or is it some form of algae? Either way, it makes a very pretty deco piece

 

Thanks in advance for any help!!

[RayWhisperer]

Exhibit A. Can't tell anything from the pic. However, from your description, I'd say Google hydroids.

Exhibit B. It's a sponge. Not a ball sponge, though. I just call them black sponge. It's similar to chicken liver sponge.

Exhibit C. Can't be positive, but it looks like it might be hydnophora coral. And yes, it's still alive... Parts of it, at least.

 

[moose2823]

Thanks Ray, I looked up hydnophora and thats definitely it! Lit up like a neon green lightbulb when the dusk cycle started and it was actinic light only.  Looks like I'll need to keep it away from anything else, but honestly where its at in the tank it shouldn't pose much of a problem.  Theres really only some incidental kenya tree and xenia nearby and I'm not worried about either of them.  Picked off two strange looking asterinas that were crawling on it (look different than any of mine), so maybe they were whats been eating it?

 

As for the tentacled creatures, I did google hydroids and what I've got looks superficially similar to most hydroids, but couldn't find an exact match online and most of the ones online look smaller and...less complex.  Heres a better pic-I put the rock on its side to show the whole colony (its at the top of the rock). 

[RayWhisperer]

The darker, single polyp is difficult to ID. If not a hydroid, it could be an encrusting gorgonian, or some type of Briareium (like GSP), though I'm not convinced of either of those. The blurry brown in the foreground looks very much like it could be hydroids to me. Not really sure what to make of any of it without a more detailed pic.

 

As far as asterina stars. It's personal beliefs/preference. I've never had a problem with them eating corals. My guess is that if they do, they are another species of asterina, or ar starved to the point of eating pretty much anything to stay alive. Then again, I'm no marine biologist, so what would I know?

[moose2823]

Spoiler

 

It does look much more encrusting gorgonian-like since the tentacles are themselves digitate, but I did also see some clavularia and briareum pics that looked eerily similar too.  Important thing is that it isn't some strange aiptasia variant, although I guess it'd be no better if it really did turn out to be hydroids.  Guess Ill let them grow out a bit and report back.  If its hydroids, I hope I'll be able to get rid of them later.

[moose2823]

A much better closeup of the tentacle colony.  Hopefully this will help with ID.  Looks like most have eight tentacles.

[RayWhisperer]

Sorry. Never checked back. 

 

Its certainly an octocoral of some sort. I couldn't begin to fathom a guess as to exactly what, though. Perhaps a location might help narrow that search. Like, is this on Gulf live rock, or some other known location?

[moose2823]

No idea, since i got it at the lfs scrap pit, but the rock has some kind of small zoa/paly growing on it too, and its not one of mine. Some of the "brown clavularia" has since died back a bit and some of the polyps have gotten a bit bigger, but its not spreading just yet, so likely not invasive (yet)

[RayWhisperer]

I'm pretty sure they aren't clauvaria, though, I guess at this point, you can call them whatever you want to. 

 

When you say bigger. How much bigger are you talking? If it's in the 10-40% neighborhood, it's a pretty good bet it's some type of gorgonian. If you are in the doubled in size range, it may be some sort of anthelia, though it doesn't have the structure I'd call "antheliaish".

[moose2823]

Its in the 10-40% range, but while the polyps look gorgonian esque, theyre standalone, not connected. Reason im calling it brown clavularia is bc if you google "brown clavularia" the first thing that comes up looks exactly like what ive got...but no further info given. The pic im talking about is attached (not mine, obviously)

http://www.marinelifephotography.com/marine/cnidaria/clavularia.htm

[RayWhisperer]

Good find. I still wouldn't trust a diving photography site. Then again, I could be way off, and the site correct. Regardless, good find.