Odd Looking Worm: Sipunculid – 5/26/09 Hi there! <Hello!> I have searched all over the Internet, including your website, for information on this one type of worm that I have found in my saltwater fish tank. The size is 30 gallons. I have one Tomato Clown, one Blue Damsel, one Yellow Watchman Goby, and a feather duster. I also have an assortment of copepods and Fireworms. <Okay> However, today I noticed a very odd worm. It looks like a sack with a long appendage on one end and a short and sharp point on the other end. It's about 1/4 of an inch when it is all "rolled up" (which is seems to "roll up inside of its skin") and 3 inches when it's all stretched out. It seems to take its long snake-like end and bury into the sand very quickly, and disappears fast. It really looks like a maggot, <Eeuwww!> ..as no feet or suckers as visible. The color is like sand. I have attached a picture. I would like to know what this is, or at least what your best guess is. I attempted to take a picture of it inside of a cup, but I had to settle for a picture of it inside the net since the flash was too bright. However, when it was in the cup, I noticed it crawling up the side of the cup into air, almost 80 or 90% out of the water. <Good news – what you have is a very common and harmless hitchhiker called a Sipunculid, aka a "Peanut Worm". Please see WWM for more information, starting here: http://www.wetwebmedia.com/pnutwrmidfaqs.htm . Here’s another excellent link as well: http://www.seaslugforum.net/factsheet.cfm?base=sipunculid > Thank you very much for the help! :) <You’re very welcome! Take care, LynnZ> Re: Odd Looking Worm: Sipunculid – 5/26/09 <Hi Jeremy, Lynn here again.> Thank you very much for the prompt reply and valuable information! <It was a pleasure! Peanut worms are neat little creatures. If you have a chance, take a look at the rockwork in your tank after the lights have been out for an hour or two. A flashlight with a red lens is best, but a regular one will do in a pinch (especially if you can dial the beam to something less than laser-like). You might be surprised how many critters are out and about, including the peanut worms. They look like elephant trunks sticking out of crevices in the rock, sniffing around on nearby surfaces. That is, until they see the bright light of a flashlight. At that point, they retract back into their homes in nothing flat!> I will certainly be visiting your site more often. <Excellent! Please let us know if there’s anything else we can do for you.> Regards, Jeremy Buff <Take care, LynnZ>

worm id, Peanut   4/8/09 I've seen this worm on numerous occasions after the lights go out. Usually it retracts when I put a flashlight on it but tonight it kept on going. I ended up capturing it. Greenish in color with light yellow bands. I would guess it is approximately 14" in length. Thank you Rick <Looks to me to be a Sipunculid. See here: http://wetwebmedia.com/pnutwrmidfaqs.htm Bob Fenner>

What is it? Peanut Worm! 1/19/09 <Hello there, Lynn here this evening.> I have a couple of these "worms" in my saltwater fish tank. <Neat> They don't like light, <No kidding. They really hate flashlights!> they stretch out to 5 inches. I was just wondering if they were bad or if I should be concerned about them. <No need for concern. They’re harmless, beneficial little Sipunculids, aka “peanut worms”. Please see WWM for more information, starting here: http://www.wetwebmedia.com/pnutwrmidfaqs.htm Here’s another excellent link as well: http://www.seaslugforum.net/factsheet.cfm?base=sipunculid Take care, Lynn>

Peanut Worm (Sipunculid)- 3/4/08
<Hi there!>
After researching and reading several articles I finally found pictures, on your site, of the creature I was trying to identify.
<Yay!>
Although I haven't seen the main body, I'm certain I have a peanut worm living in my Live rock.
<Excellent>
My question involves multiple worms. Is it common to have more than one worm living in the same hole?
<It’s not something I’ve seen or heard of (until now!) in aquaria, but they do sometimes group together in the wild in very high numbers indeed. Barnes’ Invertebrate Zoology tome states that densities as high as 700 per square meter of rock have been reported in Hawaii. That’s a lot of peanuts! Whether any share the same hole, I couldn’t tell you. However, it does say something about their tolerance for close proximity to each other.>
I have three of the "elephant trunks", coming out of the same small area, working on the rock independently of each other.
<Interesting>
(These things remind me of the creature in the movie Tremors, kinda creeped me out at first, I thought "now this can't be good" lol)
<Heheee! I know what you mean. Thankfully, these won’t chase, hurt, or otherwise try to eat you or any of the critters in your tank!>
Thanks for your help and maintaining an excellent resource for us newbies!
<You’re most welcome, thanks for sharing your observations! Take care, -Lynn>

Worm or snake?  12/28/07 <Hello Heather and Mr. Vice President... Mich here asking to be pardoned for the long delay in response.> We are setting up a reef tank (65 gallons) and have been at this for about 2 months. Two days ago we noticed this little guy. <Well I didn't invent the Internet or win a Noble Prize, but is sure looks like a Peanut worm (Sipunculid sp.) to me!> We've seen him stretched out about 2" in length. He doesn't seem to be particularly afraid of the light and will only go back into hiding whenever we try to go anywhere near him. Is he friend or foe to the reef tank? <The convenient truth, is he is a friend!> Thank you for your assistance. Heather Cleaveley & Al Gore <Welcome! Michelle Lemech> Worm or snake... Peanut worm (Sipunculid sp.) 12/29/2007 You are pardoned Mich. <Thank you kindly!> But don't really think my Al Gore can pardon anyone. <Heehee! But I bet he improves your chances of getting a dinner reservation!> Thank you very much for your assistance. <Welcome! Mich> Heather

Worm Identification?  – 10/04/07 Sorry for the blurry pics, but I was hoping you might get enough to help me figure out if this is a good or bad worm. He only comes out at night and the minute my flash goes off he is sucked up back in his hole. The worm appears to be brown with white stripes. I would have to guess it is more than 8 inches long, just how long I have no idea. When it is extending, it appears to be coming out of itself. The head part looks sort of like a short thick white feather duster when it comes out but it almost immediately goes back into itself and repeats this action over and over. It always comes out of the same hole every night, never ventures. Thanks for all of your help! Bellinda <Does it look like a Sipunculid to you: http://www.wetwebmedia.com/pnutwrmidfaqs.htm BobF> Re: Worm Identification? 10/5/07 <Hi Bellinda, Lynn here this time! Bob’s off diving - lucky fellow!> Thank you so much for your quick response. <On behalf of Bob, you’re very welcome.> I have never seen it when it is not stretched out so it is hard to tell. It stays in a hole in the rock all of the time and only comes out at night. <Typical of Sipunculids/Peanut Worms. I love these little guys. They remind me of elephant trunks, the way they appear to snuffle around looking for food - and wow, do they not like it when you shine a flashlight on them! It’s amazing how quickly they can retract back into their little abodes (not that I blame them!). They vary in color from shades of gray, brown, black, or white - some with bands of those same colors, some without.> However, I do believe that is what it is. I'm assuming from what I read that it is safe to leave this worm in my aquarium. <Absolutely. Sipunculids/peanut worms are harmless, beneficial, little detritivores, and a joy to have/watch!> Thanks Again, Bellinda <You're most welcome! -Lynn>

Hi Guys I Need Some Help Identifying This Item...Me Too!  9/10/07 Hi guys <Hi Chris, Mich here.> I need some help identifying this item... <Me too!> He showed up on some live rock and looks like he is boring his way through the rock, he seems to be eating a 1/3" hole in the rock. <This seems unlikely to me. I suspect it is just living in the hole. But could be wrong. Why do you say it appears to be eating a hole in the rock?> Its brown and about 1" tall with a 1/3" circumference. I have had a tough time trying to describe it to search for it, also turned up no results on Google and other aquarium related boards. <Well how about 20 questions? Does it react to touch or light? How does it feel? Hard, soft, smooth, rubbery? Does it move? If so how does it move? Fast? Slow? Does it appear to have a shell? Can you get a picture from a different angle? Are you using the macro feature (symbol usually looks like a flower) on your camera? Can you provide any more description, distinguishing features? My best guess, and is only a guess, is some type of sea cucumber. Mich> Chris Edwards

Likely a Sipunculid... RMF

Worm ID… Sipunculid   8/22/07 Thank you for your time, <Welcome, Mich here.> I've been visiting your site for a few years and I absolutely love it, <Nice to hear!> but this is my first question. As a background, I decided to try a 10g tank since I had to leave my 150g and 55g at my parent’s house because of the frequency of me moving. I got some sand and rocks from the 150g and started it. It did ok for a while and put in 5-6 hermit crabs and two snails. I realized though that one cannot maintain a tank when it evaporates 10-15% of its volume a day so I took out the snails and crabs and started to take out the rocks when I found a worm hanging out of the bottom of one of them. It looked very cool so I figured I could try and keep it alive. I positioned the rock so I could see it better but it disappeared after a couple days and I couldn't find, and thought it had died. I kept doing top-offs and the powerhead and lights just to see, but after a couple weeks I again decided to break down the tank. I stopped topping off and the volume cut in half. All of a sudden the worm reappeared in the same hole in the rock, slowly extending itself, possibly probing the sand. This thing had lived through very bad water quality to this point. It could retract similar to an earthworm but had more of a nub at the end resembling a mouth to my guess. I didn't have any ro water or supplies since I was breaking the tank down and sadly had to watch the little guy die over a couple days, not having any time to take it to my parents or knowledge of its good or badness. <Was a good one.> The constricted black ring formed right before he died. I pulled him out and inspected. The front end, left side of the ruler picture, was light blue with small specks and the back end, second picture, was white with black spots, which I found are tiny barbs. The back end was pretty deep in the rock and almost anchored in. Sorry this is so long, but even with the Internet I couldn't convince myself what it was and I find it very fascinating. <From your description and images I am fairly certain this was a Peanut worm (Sipunculid spp.). Sipunculids are beneficial detritus feeders. You can see some similar images here: http://www.wetwebmedia.com/pnutwrmidfaqs.htm Thanks a lot, <Welcome! Mich> Adam p.s. I have a larger version of the ruler shot, about 600kbs that shows some better detail including some internal organs if you're interested. <Sure! Please send along, will be posted.>

Unknown Marine Life, Sipunculid? - 03/17/2006 Hi Bob, <Josh here. Sorry for the delay here.> I am hoping you can shed some light on the identity of the critter in the attachments. <I'll try.> I found him accidentally while relocating a piece of live rock.  This rock is home to a toad stool that our maroon clown decided should live somewhere else! <The nerve!> I am wondering 2 things, what is this creature and should he remain a welcome resident in our reef tank? If you happen to know I would be grateful for your insight.   <Well Dawn, I'm not 100% positive here but noticed that you've re-sent this yesterday, and are still waiting. I would say this is a Sipunculid or Peanut worm. Try throwing those terms into a search.> Thank you so much for all of the knowledge and humor you have provided since I have discovered the passion of Marine Aquaria! <Thank you for allowing us to "spout off" to any who will listen.> God Bless you, Dawn Borgstrom <And you. - Josh> <<I forgot to add, if this is in fact a Peanut worm, it's completely harmless and very beneficial. - Josh>>

Spectacular Sipunculids! - 09/03/2005 Hello Wet Web Crew!   <Ahoy thar, matey!> Just had a quick question for you.  I was wondering if this looked like a Peanut Worm to you.   <Yup.  Sure does.> I've searched the internet and found a few pictures of Peanut Worms that looked like this, and several which did not match.  If you have an idea what it is, could you also tell me if this is a harmful species to have in my tank?   <This does indeed look like a Sipunculid to me.  I think they're the coolest worms out there.> Should I search the live rock to find and remove any more that might linger?   <Nope.  Just observe and enjoy.> Thank you. very much for your time!  I really appreciate it! <You bet.> Tina <Wishing you well,  -Sabrina>

Sipunculan Hello!  <Hey, Mike G here> I have what looks to be some sort of deep-sea-looking worm thing in my aquarium. <You have no idea how common that is in this wonderful hobby :-) > My pictures are a bit lacking, but could you give me a hint as to how to go about identifying this creature? <Your pictures are fine for identification of this specimen.> The most significant characteristic I've observed is that to retract back into the rock, he inverts himself and crawls back inside his own body... what a party trick, huh? It's like when you take a long balloon (the kind they turn into animals) and push with your finger on the end so it goes "inside" of itself. <He is a Sipunculan, more commonly referred to as a Peanut Worm. Harmless, benign, and entertaining.> I like him 'cause he seems to get along with my fish (one yellow-tailed damsel, one tomato clown, one royal Gramma.) Is he dangerous? <Not in the least.> If not, I don't want him to be eaten, so are there any types of fish I should avoid adding? <Butterflies, triggers, wrasses, and possibly Dwarf Angels will make a quick snack of him if provided with the opportunity.>

What is this?
Dear Bob, Anthony, or Steven,
I was hoping you could help me out with identification of what I think is some variety of worm? I have enclosed 2 pictures, though they r not crystal clear, they give you a good basic look at the creature. The first photo is lightly circled in red and the other picture is of it feeding on the acrylic wall. Things I have noticed: 1. Cannot stand light. 2. Has a minute dark green spot at the end of each lobe, which I believe are either mouths or sensors because it searches the substrate (seeming like a snake sniffing the air when it sticks its forked tongue out) and also at times if you look real close you can see the detritus it is collecting by use of its internal conveyor belt. 3. As for its size, it can easily stretch 18 inches long in search for food. Its coloring and shape is comparable to that of Caulerpa taxifolia runners, maybe a tad thinner and bit more translucent. Also, when it is roaming slowly across the substrate, you can tell it is sticky much like the “sticky hand” toy that kids play with (hand with stretchy arm that kids fling and the hand attaches to pretty much anything). 4. Finally, it retreats very quickly inside a hole in the rock (Fiji rock) no bigger than a pin (it is attached inside that hole), folding its lobes neatly before slinking out of sight.
I have never seen anything like this in any books, nor have I heard anyone having such an interesting organism. It reminds me of a Terebellid “spaghetti” worm with the way it feeds, but without the mass of tentacles. Yet is shaped like a snake’s forked tongue, with the size and translucent glow of a Euphyllia ancora sweeper tentacle. I’m sure you probably know what it is if anyone does and I am sorry if this may seem a bit jumbled, just trying to give you as much information as possible in a hopeful i.d. Thank you so much,
<we appreciate the attempt at the photo, my friend... it can be so helpful. Alas... the creature is still too vague in the image. Please do try for a better photo and perhaps post the description on reef central for Dr Ron Shimek... he is a specialist in low life forms (insert you own joke here). In sand beds and rock, that is <G>>

What is That? II
Steve Pro, Glad you had a great Father's Day and welcome to the world of parenting. Such a wonderful experience do enjoy every minute!
<She is a joy!>
I looked on the WWM and found a picture of a Bristle Worm and that is not what I have living in my overflow. The worm I have is all smooth. No leggy things. But still creepy looking. Sorry snakes and creepy crawlies give me the CREEPS. Looks to have a stomach or something towards the end of it, fatter at the bottom if that makes sense.
<When you want to know about worms, snails, and other critters, you need to go to the expert, Dr. Ron Shimek. Take a look and try to work through his "Key" to animal ID,
http://www.rshimek.com/Invertebrate%20Key%20to%20Major%20Taxa.htm 
If it lives in an aquarium, you should be able to find it there.>
Thank you, Lori
<You are welcome. -Steven Pro>

What is That? Conclusion
Thank you Steven Pro I was able to find it and quite quickly I might add, this is a great site thanks for the info. It is a Sipunculan or Peanut Worm should I leave it be in the overflow?
<Sure>
Thanks, Lori
<You are welcome. -Steven Pro>

Peanut worm? I found this worm in the intake of a powerhead that was running an undergravel filter in my marine aquarium. It is about 4 inches long and brown in color, looks similar to earthworm but not glossy instead it appears to have a rougher texture, maybe even hairs on it, a leathery appearance. I looked at the pictures of the peanut worm on Shimek's site, it looks very similar but is a much darker brown, is it likely the same type of worm?  <It is indeed... a Peanut Worm... A Sipunculid> I took this one out because I didn't know what it was and it startled me, plus when I pulled it out it tore in two pieces. In the future if I find more should I leave it in the tank and where, just put in the sand or on the live rock?  <Interesting animals, completely harmless... I'd leave it/them in place> Is it beneficial at all to the tank or harmful? Thank you very much. Kylee Peterson <Put the terms, "Peanut Worm" or "Sipunculid" in your search engines. Bob Fenner>