Anyone know what this stuff is?

[scoles_b]

Ordered a cuc, and one of the snails has this green plant like thing growing on it. It was originally just one "stem" but it is beginning to branch out a bit. I figure it's some type of macro algae? Hoping someone can identify & let me know if its good or if I should toss it. Thanks!

 

[MINItron]

It's really had to tell under the blue light, and with it being so undeveloped. I for one have a hard time calling any macroalgae undesirable. As long as it isn't overrunning your tank it is outcompeting microalgae which is always a good thing. They are all quite easy to prune when they grow out so removing excess growth, and with it excess nutrients, is a breeze.

 

[scoles_b]

I figured it was a long shot. Lol. As long as it won't root all over the place and over grow my tank I have no issue keeping it, I've just read certain kinds are hard to remove once they get their roots into the rock. I'm all for the benefits of macro! It's just strange because the way it's attached to the shell, it looks like a little black glob of glue or something. But it is growing fast, it's only been in the tank about a week.
Thanks for the input!!

 

[MINItron]

Even if you can't full remove them just pulling out the fresh growth is an effective method of nutrient export.

That glob of glue look is probably the algae's holdfast. There was likely some macroalgae growing on the shell when the crab moved in. With the crab crawling around it's not likely that the algae will ever get that big, or get a foothold elsewhere unless the crab abandons the shell in a place that the algae gets light.