I found this one as a tiny branch on a piece of live rock in the warehouse and threw it into my tank thinking it was some form of coralline that had grown over a birdsnest but hoping it was a neat macro. Now its grown into a 1.5" colony and is definitely a macro but has the consistency and color of coralline algae. Anyone have any ideas on what this one is?

Click to view attachment

whoa.

sweet.

guess, see if John Maloney can help u out.

Hopefully he chimes in here, that guy's like the macro guru

There are branching coralline species. I remember someone was trying to sell them.

Where were they trying to sell them? Hopefully they posted up some pics so that I can compare. It didn't do anything for like a month and now it's growing like crazy, weird...

try the jania species. a genus of branching coralline that looks similar to what you have. jania adherens or something like that is the first species I would look at. Not sure if it has rings on it though, been awhile since I have seen it but I think it might have. is your coralline algae flexible at the joints or anywhere? or if you bend it does it break?

It was a long time ago. All can remember is a tank with few rocks and full of little clumps of branching coralline.

Definitely looks like some of the pics of jania adherens, what's the rings that you're referring to?

It does snap if you bend it, I wonder how big it can get without starting to break due to its own weight...

wont break due to its own weight. they get like 3 inches or so per branch, but they can all go in their own direction. if you look closely on some of the jania speices they have light "rings" at what they call joints (good for you science! something that makes sense...), lets them be flexible. It is more pronounced on some species, visible on some not on some others....It is a jania sp. but visible rings would have made id'ing the species easier.

Well, I checked it out while cleaning the tank and it is flexible in between the branches. Growing fairly quickly now too, it's distinctly bigger than when I took the pics earlier in the week

bright lighting? or shaded? coralline, especially the branching varieties (or fruiting/plating varieties however you want to call them), are really picky with lighting. I have seen some species that do great under an overhang 30'' down from a cichlid light, and then bleach under anything stronger, some like bright light etc...coralline has been a interest of mine for some time. Checkout the titanoderma spp. one day. awesome. but tricky....

It's been under shaded lighting since I literally tossed it into that tank about a month and a half ago and just forgot about it, but I moved it into brighter lighting for the pic and that's when it really started taking off. I snapped off one piece and put it on the rockwork, the other one's staying on the sand. Now that I know there's branching coralline species I'll have to keep an eye out for more, those titanoderma look bad ass!

oh yeah, whole world of them. amphiroa sp. which are similar to jania, chelosporum or similar spelling are awesome too if you want to google around.