Hitchhiker ID Help

jtma508 · 05/01/2008, 10:04 AM

So it's been pretty boring in the tank lately. I'm a little over a week into the cycle. Most of the tube worms have either died-off or are laying really low. Some bristle worms, lots and lots of pods and then this morning this guy showed up...

I tried finding him online but haven't seen anything close so far. I'd estimate his girth at 1/4 - 3/8 inch. It's hard to estimate his length since he's curled-up on himself. Maybe 3-4"?? I love his head-dress. Any ideas???

jimroth · 05/01/2008, 10:43 AM

Wow, that's a cool little guy you've got there. I'm going to take a guess and say it might be a medusa worm, a kind of sea cucumber. The tentacles look very cucmber-ish. Definitely an unusual hitchhiker!

jtma508 · 05/01/2008, 11:17 AM

Doesn't look like any of the medusa worm pics I've turned-up. They seem to have more long antennae that are white. Nothing like this guy. I'm stumped. I figured it would be a quick google and an ah-hah.

styndall · 05/01/2008, 12:33 PM

Medusa worm is my only guess, too. Keep in mind that there are lots of species of medusa, and not all will be easily available in pictures on the internet.

Some description of the behavior might help. How does it move? What does it do with the feathery tentacles?

jtma508 · 05/01/2008, 12:34 PM

So it gets weirder. I noticed that it had a strange soikey thingy on its tail end:

While I watched it expelled that thingy which drifted off into the tank. Doesn't look like poop. Offspring perhaps?

Here's another pic of the critter:

jtma508 · 05/01/2008, 03:30 PM

Just wanted to bump this sucker until we get an ID.

B.C.theReefer · 05/01/2008, 03:36 PM

When in doubt, get it out. Could be harmless or it could be a killer. Just my opinion.

kar93 · 05/01/2008, 03:40 PM

Banish it to the sump until you get a positive ID.

jtma508 · 05/01/2008, 06:16 PM

BUMP

Paintbug · 05/01/2008, 06:53 PM

i believe that is going to be some type of Terebellidae sp. PM LeslieH to make sure. if any one here would know, she would.

LeslieH · 05/01/2008, 07:53 PM

Paintbug's right (very good, Grasshopper!) - it's a terebellid polychaete. Normally it would be in a tube either in a crevice in the rock or running under it. it's not happy - that's why it's out in the open. I can't identify it to genus and species unless I know the region where the rock came from and I have the worm in front of me under a microscope. Terebellids feed by extending their long tentacles over the substrate & carrying back appropriately sized particles to their mouths. they get the sand & other components that make up their tubes the same way. the prominent red feathery things are gills used for respiration.

Now the really interesting thing is the odd spikey thing at the end which drifted off. I believe that's a parasitic copepod which decided it was time to take a hike. Some copepods are internal parasites only when they are juveniles; just before or after transforming into the adult stage they move out of the host & into the water. Other copepods do it the reverse way, and yet still others are parasites during their entire life cycle. It's possible the worm has more parasites inside it.

05/01/2008, 10:04 AM	#1
jtma508 Premium Member Join Date: Jan 2008 Location: MA Posts: 1,232	Hitchhiker ID Help So it's been pretty boring in the tank lately. I'm a little over a week into the cycle. Most of the tube worms have either died-off or are laying really low. Some bristle worms, lots and lots of pods and then this morning this guy showed up... I tried finding him online but haven't seen anything close so far. I'd estimate his girth at 1/4 - 3/8 inch. It's hard to estimate his length since he's curled-up on himself. Maybe 3-4"?? I love his head-dress. Any ideas???

05/01/2008, 10:43 AM	#2
jimroth Moving Money Join Date: May 2001 Location: Rockaway, NJ Posts: 1,764	Wow, that's a cool little guy you've got there. I'm going to take a guess and say it might be a medusa worm, a kind of sea cucumber. The tentacles look very cucmber-ish. Definitely an unusual hitchhiker! __________________ Jim Roth --------------- Current Tank Info: 250G custom SPS System w/3X Radions

05/01/2008, 03:36 PM	#7
B.C.theReefer Registered Member Join Date: Jul 2007 Location: Olympia Wa. Posts: 150	When in doubt, get it out. Could be harmless or it could be a killer. Just my opinion. __________________ I am a traveller of both time and space, to be where I have been. Current Tank Info: 90gal. mostly SPS/30gal. sump/MRC MR-1 protien skimmer/ natural sunlight w/2X400w 20,000k metal halides/1X4'T12 420nm actinic provide light

05/01/2008, 06:53 PM	#10
Paintbug Registered Member Join Date: Mar 2005 Location: Stoneville, NC Posts: 6,169	i believe that is going to be some type of Terebellidae sp. PM LeslieH to make sure. if any one here would know, she would. __________________ Never ask a girl over to see your crabs!! <-Tony-> Current Tank Info: NONE currently

05/01/2008, 07:53 PM	#11
LeslieH Premium Member Join Date: Oct 2004 Location: Los Angeles, CA Posts: 3,178	Paintbug's right (very good, Grasshopper!) - it's a terebellid polychaete. Normally it would be in a tube either in a crevice in the rock or running under it. it's not happy - that's why it's out in the open. I can't identify it to genus and species unless I know the region where the rock came from and I have the worm in front of me under a microscope. Terebellids feed by extending their long tentacles over the substrate & carrying back appropriately sized particles to their mouths. they get the sand & other components that make up their tubes the same way. the prominent red feathery things are gills used for respiration. Now the really interesting thing is the odd spikey thing at the end which drifted off. I believe that's a parasitic copepod which decided it was time to take a hike. Some copepods are internal parasites only when they are juveniles; just before or after transforming into the adult stage they move out of the host & into the water. Other copepods do it the reverse way, and yet still others are parasites during their entire life cycle. It's possible the worm has more parasites inside it. __________________ Cheers, Leslie So many worms, so little time... Natural History Museum of Los Angeles County

05/01/2008, 11:17 AM	#3
jtma508 Premium Member Join Date: Jan 2008 Location: MA Posts: 1,232	Doesn't look like any of the medusa worm pics I've turned-up. They seem to have more long antennae that are white. Nothing like this guy. I'm stumped. I figured it would be a quick google and an ah-hah.

05/01/2008, 12:33 PM	#4
styndall Registered Member Join Date: May 2007 Posts: 282	Medusa worm is my only guess, too. Keep in mind that there are lots of species of medusa, and not all will be easily available in pictures on the internet. Some description of the behavior might help. How does it move? What does it do with the feathery tentacles?

05/01/2008, 12:34 PM	#5
jtma508 Premium Member Join Date: Jan 2008 Location: MA Posts: 1,232	So it gets weirder. I noticed that it had a strange soikey thingy on its tail end: While I watched it expelled that thingy which drifted off into the tank. Doesn't look like poop. Offspring perhaps? Here's another pic of the critter:

05/01/2008, 03:30 PM	#6
jtma508 Premium Member Join Date: Jan 2008 Location: MA Posts: 1,232	Just wanted to bump this sucker until we get an ID.

05/01/2008, 03:40 PM	#8
kar93 Registered Member Join Date: Oct 2007 Location: Lincoln Posts: 5,521	Banish it to the sump until you get a positive ID.

05/01/2008, 06:16 PM	#9
jtma508 Premium Member Join Date: Jan 2008 Location: MA Posts: 1,232	BUMP