Critter in my live rock

mud · 05-17-2002, 11:51 PM

I saw a critter in my tank I am using to cure some new live rock. I looked on the reefs.org Hitch Hiker faq and did not see it. It looked similar to an earthworm about 3 inche long. It was brown and, unlike earthworms, it seemed to have several hair thin, white tentacles. Any idea what it could be?

mud

RWD · 05-17-2002, 11:57 PM

Sounds like a bristle worm. They come in more the one color. The one at reefs.org is red but I have seen them pink, brown, etc.

mud · 05-18-2002, 12:12 AM

Not a bristle worm. I have lots of them. I probably was not clear in my description. It looks JUST LIKE a common earthworm, except it has several 2-3 inch long hair fine, maybe spider web fine tentacles. It moved like an earthworm as well. When startled all the tentacles withdrew into the critter.
mud

tdwyatt · 05-18-2002, 01:52 AM

Quote:

Originally posted by mud
Not a bristle worm. I have lots of them. I probably was not clear in my description. It looks JUST LIKE a common earthworm, except it has several 2-3 inch long hair fine, maybe spider web fine tentacles. It moved like an earthworm as well. When startled all the tentacles withdrew into the critter.
mud

Was is segmented or un segmented? Did the tentacles come from an oral opening or the sides of the body, and if so, how far from the head (a picture would be worth the proverbial 1000 words...) unsegmented worms would prolly have oral tentacles, segmented worms with the appendages coming from lower segments would prolly have "gills" but may also have tentacles (heh, look at spaghetti worms, they have both!), especially if the threads are from the front 1/3 of the organism. Os the head pointed or blunt? are both ends the same? Did it appear to burrow? Did it have a clitium (non-segmented band of cuticle) like an earthworm? Did it come from a burrow or tube in the sand or from the Live Rock itself? Where did the rock originate? Without a picture, I can prolly limit down to one or two genera, but even with the pix, I will only be able to get close, possibly narrowing it down based on behavior and the questions I have already asked. VERY LARGE NUMBER of creatures in this group of organisms.

Stang69 · 05-18-2002, 02:23 AM

Peanut worm perhaps

Jeff

oregon_gorge · 05-18-2002, 02:42 AM

Just a thought, I rescued a 55 gallon tank from some people that had let it go. 9" long hair algae and 5" low on water. Dont know how the things lived in there.

Anyway, there was a feather duster in that mess, barely able to extend above the HA. After I cleaned the tank and started it back to recovery, the FD dropped his crown and then crawled out of his tube. He looked just like what is described. I saw one at a LFS in Vancouver last weekend out of its tube too.

Maybe?

HTH Chris

Doug1 · 05-18-2002, 01:15 PM

I have found the earthworm looking guys, but so far I haven't noticed any hair like tentacles. My theory is if you don't se it eating something you value, let it be

mud · 05-18-2002, 11:40 PM

Quote:

Originally posted by tdwyatt
Was is segmented or un segmented? Did the tentacles come from an oral opening or the sides of the body, and if so, how far from the head (a picture would be worth the proverbial 1000 words...) unsegmented worms would prolly have oral tentacles, segmented worms with the appendages coming from lower segments would prolly have "gills" but may also have tentacles (heh, look at spaghetti worms, they have both!), especially if the threads are from the front 1/3 of the organism. Os the head pointed or blunt? are both ends the same? Did it appear to burrow? Did it have a clitium (non-segmented band of cuticle) like an earthworm? Did it come from a burrow or tube in the sand or from the Live Rock itself? Where did the rock originate? Without a picture, I can prolly limit down to one or two genera, but even with the pix, I will only be able to get close, possibly narrowing it down based on behavior and the questions I have already asked. VERY LARGE NUMBER of creatures in this group of organisms.

It did not appear to be segmented, but it could be the segments were too small for my old eyes to see.
The tentacles appeared to come from the body of the critter, not the mouth. the head appeared to be pointed, and both ends appeared to be very similar. I did not see a clitium. When I first saw the worm it was on the front of the tank; I do not know if it came from the rock or the sand. I have not seen it today. Most of the rock was "premium fiji uncured" from Premium Aquatics.

Wish I had a pic, but been spending all available money on the tanks. One of these days I will rectify that situation.

I guess it is not as important to me that I know what it is as much as I know it will not harm other things in the tank.

mud

tdwyatt · 05-19-2002, 11:32 PM

heh! Not to worry, most of these critters are prolly deposti feeders, based on what is most likely and on the descriptions so far. If it was truely a non-segmented worm, prolly one of the phyllum of Coelomate worms, very primitive worms that barely demonstrate bilateral structure, all of which share a similar general appearance and lack segmentation. The most likely will not eat your corals, and will not consume anything more than detritus and biofilms. They are great for your sandbed, and having one that large will be great for populating your benthos. These worms eat substrates containing organic material and digest a portion of the organic material (usually some bacteria and misc carbon compds) and deposit the remaining organic material and nonorganic sediments as continuous piles called castings. These are part of the sandbed fauna we want to encourage to develop and populate the sand bed. Congratulations are in order!

Interesting bit of trivia, although they do move like earthworms (peristalsis) in some phyla, most move through a cycle of eversion/retraction to burrow through the substrate. They extend a eversible body part, usually the proboscis or pharnyx, This body part then is swolen to expand that body part, forming an anchor that the creature uses to pull a large portion of it's body into, after which it retracts the remaining body behind it into the space and repeats the cycle to extend the proboscis into the substrate ahead of the main body mass.

Hope this helps

mud · 05-20-2002, 08:52 PM

Quote:

Originally posted by tdwyatt
heh! Not to worry, most of these critters are prolly deposti feeders, based on what is most likely and on the descriptions so far. If it was truely a non-segmented worm, prolly one of the phyllum of Coelomate worms, very primitive worms that barely demonstrate bilateral structure, all of which share a similar general appearance and lack segmentation. The most likely will not eat your corals, and will not consume anything more than detritus and biofilms. They are great for your sandbed, and having one that large will be great for populating your benthos. These worms eat substrates containing organic material and digest a portion of the organic material (usually some bacteria and misc carbon compds) and deposit the remaining organic material and nonorganic sediments as continuous piles called castings. These are part of the sandbed fauna we want to encourage to develop and populate the sand bed. Congratulations are in order!

Interesting bit of trivia, although they do move like earthworms (peristalsis) in some phyla, most move through a cycle of eversion/retraction to burrow through the substrate. They extend a eversible body part, usually the proboscis or pharnyx, This body part then is swolen to expand that body part, forming an anchor that the creature uses to pull a large portion of it's body into, after which it retracts the remaining body behind it into the space and repeats the cycle to extend the proboscis into the substrate ahead of the main body mass.

Hope this helps

You describe exactly they way I watched it move and I recall seeing several worm castings you mention. Wahoo help for the sand bed.

Thanks for the info
mud