What's on this shell?

[weagle117]

I noticed the little fingerlike projection on the bottom of this shell a few weeks ago. It may have gotten a little bit larger but not by much. It does not move. A hermit crab even moved the shell around a little, turned it upside down but didn't knock it off. On the rock in the back of the tank (other pics) there are 3 (1 a little away from the other 2) that looks similar- not quite as pointed. I removed an LED light @a week ago and am having to use an old light until my new reef capable LED light comes in... could be why the little thing on the shell has not grown any... maybe? Anyway, I'm very curious about what this is. Also, what is the bright green spot (a couple of red ones are around the 1 green spot) that has popped up on the shell? All of a sudden one day, this bland little shell started becoming colorful and got this little projection. Please inform if you have any ideas. Thanks

 

[weagle117]

More unidentified aquatic objects (UAO's)

What are these 3 yellow balls? The top one is much more yellow than the other 2- which are pale yellow or even off-white? I'm guessing maybe sponges.... if correct, any particular kind?

What is the gray mossy stuff on this rock. It is only on the one, right now.

This shell was a gray/whitish color and became a pretty lime greenish color. In person the color is much more vibrant and pretty but I'm a little worried about algae or something that might take over . It doesn't have an texture to it so far.... Any ideas?

Is the red/burgandy color at the top of the shell coraline algae? In some places (on other items as well as this particular shell) it looks like a scale and in a few there are hard flowerlike projections that are more red than burgandy that are growing off of the shell. At the bottom of the shell there are white starlike things that are spaced apart. They seem to be hard too. They are on several shells & rocks and seem to space out and grow slowly. Sorry so many questions... but any ideas will be appreciated

 

[weagle117]

I'm not sure what I did here... I think I responded to my own post when I thought I started another one.... Sorry!

 

[mr_X]

spionid worms.
the yellow balls are sponges
possibly foraminiferans
green algae
coralline algae.

 

[weagle117]

what's on this shell -part 2

After googling everything it looks like it's all fairly beneficial except the green algae. Hopefully, the yellow tang, hermits, & turbo snails will help me keep the algae population down. I'm guessing that I'm feeding too much as well so I'll take that back a notch.
A piece of barnacle that was totally white/pink yesterday has a big patch of yellow/green on it today. I've attached a few pics that I just took. The first pic is of the barnacle piece where it has been for the past few days.... keeping the grassy looking coral (I can't remember the name of it) from falling behind the live rock. The 2nd picture is a close up of the same barnacle...I moved it where I could see it better. The 3rd pic is my tang next to the shell I send the original pic of... it has gotten greener. What else should I do to control it. I love it right now but I'm guessing this is going to be a problem?
Thanks for your expert id & advice, Mr. X

 

[mr_X]

i wouldn't be too concerned with that algae. just watch your feeding and keep with a reasonable water change regimen, with good source water (R.O.D.I.) and you should be ok.
-the grassy coral is green star polyps or GSP, a member of the gorgonian family.