Blue-green worm with white zig-zag marking ID help please

JVU · 05/07/2017, 08:22 PM

IMG_0324.jpg

Hi,

So last night I found this striking blue-green worm (I think it's a worm) in my tank. He's about 1/4" diameter with a round body and a flat head that has the prominent zig-zag white lines on it.

He stretched out from a rock crevice onto the sand about 6" or so, grabbed and swallowed a blue leg hermit crab in shell and retreated into the crevice. He spit him out a minute later. Never seen him before and can't find him again today.

He's actually quite a beautiful specimen but seeing him try to eat a crab was off-putting. I'm wondering what it is and if I should be worried enough to try to remove him. I have a mixed reef.

Thanks!
John

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badbreath · 05/07/2017, 08:32 PM

How long has it been since you've added something out could've hitch hiked in on?

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JVU · 05/07/2017, 09:12 PM

I haven't added any rock or coral on rock in a long time, at least a year or two. I've recently (within the past month) added a clean up crew like small snails and crabs, as well as an anemone, small plate coral, arrow crab. I wouldn't be surprised if he's been in my tank for a long time hidden, I have a lot of rock work and crevices.

I just came across a WetWebMedia archive FAQ page where Bob Fenner ID'd something that looked similar as a Nemertean worm. There were disparate discussions of it being a carnivore that may go after clams and invertebrates, but also that it might be safe in a reef tank.

I'm hoping someone here might have some more experience and info.

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pagojoe · 05/07/2017, 11:30 PM

Yes, it's a nemertean. You can probably search Notospermus on this forum and get some good info. They are predatory.

JVU · 05/08/2017, 01:00 AM

Thanks, I did find some additional useful discussions with that name. Sounds like he will be a problem. Finding and removing him won't be easy though.

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Shawn O · 05/11/2017, 12:41 PM

Tie a small crab to a stake and leave him out overnight.

JVU · 05/11/2017, 05:39 PM

Poor sacrificial crab

I'm planning a tank upgrade soon so I'll try to find and remove him then, but even with looking closely at every rock I'm not confident I'll find him.

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05/07/2017, 08:22 PM	#1
JVU Registered Member Join Date: Sep 2014 Location: East Bay, Northern California Posts: 83	Blue-green worm with white zig-zag marking ID help please IMG_0324.jpg Hi, So last night I found this striking blue-green worm (I think it's a worm) in my tank. He's about 1/4" diameter with a round body and a flat head that has the prominent zig-zag white lines on it. He stretched out from a rock crevice onto the sand about 6" or so, grabbed and swallowed a blue leg hermit crab in shell and retreated into the crevice. He spit him out a minute later. Never seen him before and can't find him again today. He's actually quite a beautiful specimen but seeing him try to eat a crab was off-putting. I'm wondering what it is and if I should be worried enough to try to remove him. I have a mixed reef. Thanks! John Sent from my iPhone using Tapatalk Pro

05/11/2017, 12:41 PM	#6
Shawn O Registered Member Join Date: May 2014 Location: People's Communist Republic of Massachusetts Posts: 1,474	Tie a small crab to a stake and leave him out overnight. __________________ "55gal glass box full of water, rocks and some not-so-amused little fishes" 2x Occellaris, 1 Pajama, 1 Neon Dottyback. Current Tank Info: 55gal tank, sumpless, ReefOctopus Classic 90, Twin bulb T5.

05/07/2017, 08:32 PM	#2
badbreath Registered Member Join Date: Jun 2011 Location: Garden Grove 92845 Posts: 536	How long has it been since you've added something out could've hitch hiked in on? Sent from my LG-H811 using Tapatalk

05/07/2017, 09:12 PM	#3
JVU Registered Member Join Date: Sep 2014 Location: East Bay, Northern California Posts: 83	I haven't added any rock or coral on rock in a long time, at least a year or two. I've recently (within the past month) added a clean up crew like small snails and crabs, as well as an anemone, small plate coral, arrow crab. I wouldn't be surprised if he's been in my tank for a long time hidden, I have a lot of rock work and crevices. I just came across a WetWebMedia archive FAQ page where Bob Fenner ID'd something that looked similar as a Nemertean worm. There were disparate discussions of it being a carnivore that may go after clams and invertebrates, but also that it might be safe in a reef tank. I'm hoping someone here might have some more experience and info. Sent from my iPad using Tapatalk Pro

05/07/2017, 11:30 PM	#4
pagojoe Team RC Member Join Date: Feb 2007 Location: Conroe, TX Posts: 2,761	Yes, it's a nemertean. You can probably search Notospermus on this forum and get some good info. They are predatory.

05/08/2017, 01:00 AM	#5
JVU Registered Member Join Date: Sep 2014 Location: East Bay, Northern California Posts: 83	Thanks, I did find some additional useful discussions with that name. Sounds like he will be a problem. Finding and removing him won't be easy though. Sent from my iPhone using Tapatalk Pro

05/11/2017, 05:39 PM	#7
JVU Registered Member Join Date: Sep 2014 Location: East Bay, Northern California Posts: 83	Poor sacrificial crab I'm planning a tank upgrade soon so I'll try to find and remove him then, but even with looking closely at every rock I'm not confident I'll find him. Sent from my iPhone using Tapatalk Pro