Couple of unidentified life forms

[Benny9]

Hi! So my tank has entered the ugly stage and as I impatiently wait for the right time to add intentional inhabitants, I like to spend time (along with my kids) exploring the expanding ecosystem with a magnifying glass to see what might have found its way in there. We seeded the tank with some mature live rock from the lfs and I know it's risky but I'm old school and have a love for seeing what hitchhikers might have caught a ride on the rocks. We have the usual assortment of bristle worms, tube worms and algea but I've noticed a couple I don't know offhand. One is a white/clear membrane looking thing, maybe some kind of sponge? I had a spong with a similar color many years ago but it was more tube shaped... For reference The little tube worm under it is about 1 cm long.
The other is a cluster of red bulbs or polyps on little stalks or so it seems. The red thing is about 1 cm across.
Looking forward to hearing what you all think!

 

[phillyb614]

Tube looks like a minature feather duster. Harmless filter feeder. I have them all over my tank.

 

[Benny9]

Tube looks like a minature feather duster. Harmless filter feeder. I have them all over my tank.

Those I know pretty well, we have a bunch of those and the spiral ones as well. I was actually referring to the white membrane above the tube worm/feather duster.

 

[ISpeakForTheSeas]

Yeah, the white is a sponge (most likely harmless/beneficial) and the red is Red Grape Algae:

Yeah, that's definitely a sponge. Most sponges are completely harmless/beneficial, but some can be invasive and/or harmful to corals (thankfully, these are rare).

To tell if a sponge is chemically harmful: if a healthy, established coral starts closing up or looking to be in bad shape on the side closest to the sponge as the sponge grows closer to it, and nothing else has happened (lighting changes, parameter swings, pests, etc.) that could explain it, then the sponge is probably chemically harmful.

Chemically harmful sponges are very rare.

For invasive sponges: unless it shows signs of being chemically harmful or starts actively growing over and smothering a coral's flesh/polyps, it's harmless. These can grow over the skeletons of corals, around the base/stalks of corals, even up into the water column above corals (where they're over the coral but not growing on the flesh or polyps themselves), etc. without harming the coral at all - as long as the coral flesh and polyps can get food, light, and flow, the sponge is harmless.

Invasive sponges are moderately rare.

Invasive and chemically harmful sponges are incredibly rare.

I’m not an expert, but it looks to me like it may also be “Red Grape Algae” (to my understanding, both red bubble algae and red grape algae are Botryocladia spp.) - red grape is typically considered positive, red bubble is not. My understanding is that if the bubble is growing on a stalk (if it has a stem), then it’s red grape; if there’s no stalk/stem (just a bubble not raised off the surface of whatever it’s growing on), then it’s red bubble.

 

[Benny9]

Yeah, the white is a sponge (most likely harmless/beneficial) and the red is Red Grape Algae:

Awesome, thanks for the quick response! No fish or corals yet so we'll just let the some so it's thing for now and just keep an eye out once we start with the corals. The algae is definitely on a stem. So time to do a little research. Really appreciate the ID!

 

[Benny9]

So things have evolved. The tank has a fully functioning cycle and the ugly phase is in full swing. The sponge was swallowed up by algae days ago. The red/purple thing however is 4-5 times the size it was when I first posted and had changed a lot. Any new ideas?

 

[ISpeakForTheSeas]

So things have evolved. The tank has a fully functioning cycle and the ugly phase is in full swing. The sponge was swallowed up by algae days ago. The red/purple thing however is 4-5 times the size it was when I first posted and had changed a lot. Any new ideas?

With it growing out instead of up, that may actually be red bubble algae - the species I've heard it called is Botryocladia skottsbergii.

 

[Benny9]

With it growing out instead of up, that may actually be red bubble algae - the species I've heard it called is Botryocladia skottsbergii.

I looked into that just now and I don't think that's it (Really appreciate the suggestion though). The problem is that what started out as bubble shape no longer look round. Wish I could get a better shot but my macro lense won't focus that far into the tank. I'm tempted to pull the rock to get a better shot. Here's today's pic though.

 

[ISpeakForTheSeas]

I'm tempted to pull the rock to get a better shot.

Yeah, if you don't think it's red bubble algae, then I'd pull the rock for pics.

 

[Benny9]

Yeah, if you don't think it's red bubble algae, then I'd pull the rock for pics.

Ok so I pulled the rock but it's hard to get a good look at it out of the water. Took a pic anyway. Outside the aquarium light it looks tan or brown. I moved the rock closer to the glass though so that I can keep a better eye on it as it develops. Google lens thinks it's a rose bubble tip anemone but it doesn't seem very anemone like to me.

 

[EeyoreIsMySpiritAnimal]

Does it appear to have any sort of skeleton? The first pic almost looks like hammer tentacles...

 

[Benny9]

Does it appear to have any sort of skeleton? The first pic almost looks like hammer tentacles...

It certainly seems to have structure once I took the rock out of the water. It's in a relatively high flow area also and it doesn't move with the current at all. I guess I'll have to wait a while and see how it develops.

 

[Benny9]

I'm just watching this thing develop until we have a positive ID. As a benefit to my obsession with studying it, I spotted a tiny vermetid snail while looking with a high magnification magnifying glass. It was maybe a mm long tube. While watching I saw it deploy A net and then reel it in. A stainless steel pick took care of that. No signs of other nets anywhere yet. Fingers crossed. Here's the newest picture of the thing.

 

[ISpeakForTheSeas]

I'm just watching this thing develop until we have a positive ID. As a benefit to my obsession with studying it, I spotted a tiny vermetid snail while looking with a high magnification magnifying glass. It was maybe a mm long tube. While watching I saw it deploy A net and then reel it in. A stainless steel pick took care of that. No signs of other nets anywhere yet. Fingers crossed. Here's the newest picture of the thing.

Look up Colpomenia and see if any of those species look like a match.

 

[Benny9]

Look up Colpomenia and see if any of those species look like a match.

Maybe? What I have isn't translucent at all and seems to have a more rigid structure. That being said, it's also only maybe 2 cm across so those characteristics may be something it will develop as it matures. At the moment I don't have fish or coral in there yet so I'm not afraid to let it go and see what happens.

 

[Benny9]

Update. Attached are pictures of before and after the mystery organism was found by a turbo snail. It's hard to see in the picture but what was left behind was two "leaves" and dark red stems with bright orange edges. The stems have an indentation in the center. The remaining leaves or whatever they are are growing out of the sides of the stems.