Please help me ID this LR hitchhiker!

[Sanveann]

We set up our first-ever SW saltwater tank last weekend and are waiting for it to cycle. We've noticed two of these little critters (plants?) in there and wanted to make sure they aren't anything harmful. I'd say they're both about an inch across (including tentacles, if those are in fact tentacles) and are somewhat transparent:


liverock by sanveann, on Flickr

We've also got a number of these little tube-like things growing. I'd say they're no more than half an inch tall:


tubethings by sanveann, on Flickr

Any help would be much appreciated!

[jeffesaurusrex]

First one is an Aiptasia, considered a pest as they will reproduce quickly, stinging and out-competing surrounding coral. One went to 5 in a matter of days on me in my pico tank.

Second one isn't a very good picture, looks like hydroids to me. They're considered pests as well.

You can remove the Aiptasia with one of the commercial cures, Joe's Juice worked perfectly for me. Or you can use a biological cure- Berghia Nudibranches, Peppermint shrimp (not camel shrimp!), filefish, and the Copperband Butterfly all eat them. Berghias are the only ones really guaranteed to eat them, because it's all they eat, but once the Aiptasia is gone you won't be able to feed the Berghia any longer. Copperband will eat other coral too, and so will the filefish but there are successful examples of both being kept in a reef. Peppermint shrimp I think the reccomendation is 1 per 25g, I put one in my pico tank and he wiped out the aiptasia there but once he was in my 75g he wouldn't touch em.

For the hydroids I removed them mechanically, I.E., scraped them off with a little paring knife.

[Sanveann]

Thanks, Jeff! I had just come across a picture of aiptasia and was worried that's what it was :P

The second one isn't very good, I know ... that was the best pic I could manage! They're about half an inch tall and look like little light-brown tubes. They're open at the top, and almost transparent at the tip. I looked up photos of hydroids but can't find any that look like these at their current stage. (Edited to add ... they don't appear to move at all, if that helps.)

[angelofrapture]

I agree with aiptasia on the first

The tubes could be from hydroids, tiny feather duster worms, or vermetid snails. Watch to see if anything pokes out the hole.... vermetids will have a line or two of mucus to catch food, which will look like a bit of spiderweb. Feather dusters and hydroids have a similar round fan of filaments at the end. My tiny feather dusters often retract quickly into their holes when they sense movement (walking by the tank quickly, moving something in the tank near their rock) and come in a lot of colors, sometimes striped. My hydroids all have a kind of cinnamon-brown color and do not seem to retract at all. The tubes could also be leftover from something that no longer lives there.

[Sanveann]

Thanks, Angel! I did manage to get a better picture with my phone of the hydroids (?). (Edited to add: My husband informs me that when poked, the tubes snap instead of bending. That means they're probably feather dusters, right?)


morestuffonrock by sanveann, on Flickr

And here's a link to the larger version: http://farm7.static.flickr.com/6164/...dba18e55_b.jpg

[thebkramer]

look like vermetid snails to me

I love my vermetids.. but some find them annoying.. they "spit" a string of mucus out in the water column.. let it collect food.. then suck it back up! pretty cool little guys IMO.. and good filter feeders!!
Enjoy!!!

[cloak]

They look like vermetid snails to me as well. The population will usually rise and fall due to the amount of food that's available in the system. I used to have alot when my tank was first set up. Now, not so many. Here's a good article.

http://www.reefkeeping.com/issues/2005-01/rs/index.php

[Sk8r]

Spionids, on the second. Mild nuisance. I actually like them. The aiptasia can be a nuisance, but not a huge one. I must have 20 of them in my dt with a huge amount of coral and a clam, and Aiptasia X has done no good. I'm going after juvvie peppermint shrimp next. They'll slowly do them in, starting with the babies---kind of hit and miss, but if you don't overfeed, they'll get hungry. Ordinarily I advise against getting a pest to eat a pest, but in the case of aiptasia, they're still the best cure.

[Ebisan]

You can also use kalk. Mix it with some water to make a paste and use a syringe to inject it into the mouth or cover them if they retreat into the rock. Got rid of mine this way.

[Sanveann]

Thanks so much for all the advice, everybody! I love how helpful and friendly this forum is to newbs

We still haven't seen anything coming out of the little tubes. I'm assuming whatever lived in them is dead, but we'll keep a close eye on them. As for the aiptasia, I think we're going to go the peppermint shrimp route for now and see how that works.

[cloak]

If you have any epoxy lying around, you can use that to smother some of those aptasia.