FAQs about Marine Worms, Vermiform
Animals Identification 18
Related FAQs: Worm IDs 1, Worm
IDs 2, Worm IDs 3, Worm IDs 4, Worm
IDs 5, Worm IDs 6, Worm IDs 7, Worm
IDs 8, Worm IDs 9, Worm IDs 10, Worm
ID 11, Worm ID 12, Worm ID 13, Worm ID
14, Worm ID 15, Worm ID 16, Worm ID
17, See Also: Flatworm
ID 1 +, Nemertean, Proboscis,
Ribbon Worm ID 1, Nematode,
Roundworm ID 1,
Nematomorpha, Horsehair Worm ID
1, Acanthocephalans, Thorny-headed Worm ID
1, Tubeworm/Featherduster ID
1 +, Bristle Worm ID 1 +,
Hirudineans, Leech ID 1, Sipunculids, Peanut Worm ID 1, Echiuran Worm ID 1, Invertebrate Identification, Worms 1, Worms 2,
Worms 3, Flatworms/Planaria, Fire/Bristleworms, FAQs on: Worm Behavior, Worm
Compatibility, Worm Selection,
Worm Systems, Worm Feeding, Worm
Worms, Featherduster Worms,
very tiny (0.5-1 mm long) white worms in saltwater tank... Food,
Hello. I'd like to say thanks ahead of time, and apologize if this
question is already posted. I couldn't find my specific problem.
I've spent a lot of time trying to identify these tiny worms and how to get
rid of them, but nothing I come across seems to match. I have a
36 gallon saltwater tank that has been running for almost 4 months.
There are hundreds of tiny tiny white worms on my glass and I'm sure on
everything else, but its hard to tell because they are so small. They
are about 0.5 -1 mm in length, and far thinner in width. They barely
move around. They are not curled or spiraled, and don't appear to be
flat. I've attached a picture that I took through a 10x magnifying
glass. The closest match I could find was possibly Planaria, but most
people describe them as larger than these guys.
<There are many possible species, even families that these could be...
almost all innocuous... Of no harm to what people keep>
I am sure the worm population exploded because of overfeeding my
There are 2 clown fish, and a few small snails and crabs. All my water
parameters check out fine, temp is around 76, sg at 0.022.
<Mmm, missing the 1 in front. Your water is assuredly more dense than
I started with an Aqua Clear 50 filter, but was plagued with cloudy water
for about 2 months. I decided to add a Bio-wheel 150 because I thought
the Aqua Clear wasn't moving the water around enough. I still had
<I'd run both>
I could see swirls of hundreds of tiny particles floating around.
After a month of this, I caved in and tried Kent marine clarifier.
<Not a fan of such products>
After 2 doses over 2 days, it didn't help the cloudy water, it dropped my
pH, and caused one of my clowns to have what I can only describe as
seizures. I have been diligent about weekly water changes (10-20%) and
sand vacuums from the start. Finally, about 2 weeks ago, my water
cleared and the pH is back at 8.2. When the water cleared was when I
could really see the hundreds of tiny white "particles" stuck to the glass.
I did notice it before, but it was in small amounts, and I always would
scrape it off. The particles would just come back, and now in
greater numbers. It wasn't until about 3 days ago, when I took out a
magnifying glass, that I realized the particles are worms. I
immediately reduced feeding, did a big scrape of the glass, rinsed my
filters, added 50 micron felt to the filters, and did a big time siphon of
the sand. Sure enough, the little buggers are quickly repopulating on
the glass. Do you know what they are, and have any suggestions on what
to do to get rid of them?
<As you state, some "type" of worm. As I've stated, not dangerous, though
unsightly... As you mention, they are mainly "due" to your overfeeding...
These worms will "go" with improved water quality, and time just going by...
I would NOT treat the system to eradicate them... as their deaths might well
present a toxic soup...>
Also, and this may sound silly and paranoid, should I be worried about any
human infection of these things?
<Not likely at all; no>
The fish seem fine. I always wash my hands after cleaning the tank,
but these guys are so small, it does have me worried. Thanks for your
time. I appreciate your help!
<Not to worry... Please search WWM w/ the string "Marine Worm
Identification" and take some time perusing what we have there. Also
consider reviewing our sections on marine filtration. All will be well here
in time I assure you.
Re: very tiny (0.5-1 mm long) white worms in saltwater tank
Thanks for the fast reply! I am running both filters, and sorry
about the typo, I did mean 1.022. I'll just keep doing what I'm
doing, and watch it with the food. Thanks again!
<Certainly welcome. Cheers, BobF>
Re: Help Needed!!
Any idea what are these 2 things??? 2/4/13
The green very long one , has it's bottom at the left of the screen , so
as soon as you put a flashlight on it it shrinks in the hole at the left
It only gets out at late night after all the lights are gone and it goes
back in the hole just before the lights light up early in the morning.
<... Likely an Echiuran. See here:
Also after these 2 creatures an Euphyllia is damaged and maybe a
Re: Help Needed!!
You are great !!! But you already know that !! :):):)
And the other creature??? You believe it is the same??
<The "stringy thing" of the same colour? Yes if so. BobF>
Re: Help Needed!! 2/5/13
Yup that was the one I was talking about.
Thank you again!!
odd worms 12/12/12
Hello WetWeb crew, A few days ago I noticed
some odd creatures on my glass. I have 30 gallon salt
water tank that's been established for almost a year now.
They are about 1-3 mm long and sort of a brown red color.
They look like small worms with bodies about a third as wide as they are
long. I thought they were stationary but upon further examination
I noticed a few of them moving around. They have a white tip were
there head would be and their tails sort of form a "U" shape with the
sides reaching out further then the middle. What are these things?
And should I concerned about them?
<Likely some species of Polychaete, and not likely worrisome. With time
going by, succession, predation by some other species, group, they'll
likely pass. Bob Fenner>
Clear tube worm identification 11/17/12
I like your website and I hope you can help me out. I was lifting a
few pieces of live rock to see if my red banded Longfin Basslet was still alive
(yes i found him nice and healthy). However, I came across this clear
tubed animal. He has small tentacles for his mouth are and stretches
around 2 inches. He has a digestive tract that you can see. I
removed him and put him in a holding pen in my sump. The picture enclosed
is the best picture I can send you. Please let me know if you can identify this
mysterious creature (I hope he is safe to put back in my dt)
<Mmm, this appears to be not a worm, but a sea cucumber... Not problematical...
I'd put it back in your tank and enjoy it. Bob Fenner>
Powder Blue Tang, parasitic worm? 9/28/12
Good evening, I purchased a Powder Blue Tang, a Desjardini Tang and two
Fairy Wrasse's through Liveaquaria.com a little over two weeks ago. They
all went into a 29 gallon bare bottom quarantine tank with a few pieces
of live rock out of my sump to help with water quality. I did twice
daily water changes to maintain the water quality for the first 10 days
when it finally leveled out. All of the fish are doing great, eating
frozen Mysis in the morning followed with seaweed blend on a lettuce
clip. Even the wrasses seem to enjoy eating the seaweed which surprised
me. Anyways, all fish looked quite healthy when they arrived. I did not
do a freshwater dip as I now see you recommend. The third day I saw what
appeared to be a thread hanging on the eye of the Powder Blue Tang. I
watched it closely for another day and it appeared to stay the same.
Assuming it was a parasite I dosed the tank with PraziPro per
instructions. Within 3 hours the
"thread" had detached and was on the bottom of the tank. I used a
transfer pipette to suck it up and placed it under a microscope, please
see attached photo.
<I see this/it>
I'm assuming some sort of a fluke.
<Mmm, a worm of some sort... but too spiny to be a Trematode in my
I have not seen another one on any of the fish, nor have I seen any
other signs of disease. I'm keeping the tank at 80 degrees and specific
gravity of 1.020. My question is, I was doing such large water changes
twice daily to keep the water quality up so I would replace the PraziPro
with the appropriate amount but I only did this for four days. The
instructions say to dose with a single treatment lasting for 5-7 days.
Do I need to do another treatment or should I just continue to watch.
<I'd do the latter>
I plan on leaving them in quarantine for at least 4 to 5 weeks total as
I know the Powder Blue's are known as ich magnets. Honestly, now that
I've got them I'm completely paranoid that I will introduce crypto to my
main tank, it's a 180 gallon reef and I've been down that road before
several years ago. I left it fallow for 6 weeks and haven't had a
Would I be better off with a little longer quarantine?
<A trade off at about six weeks... little benefit vs. stress past that
period of time>
I've read that the powder blues don't always do well so that is somewhat
of a concern, however, this is one of the healthiest groups of fish that
I've purchased in several years. Thanks for your time.
<Am going to "shop around" your pic... See what others think. To me this
looks like a juvenile Errantiate Polychaete... Bob Fenner>
<Sabrina looked and she concurs that this appears to be a
small Bristleworm... I think it/this "just happened" to be on the Tang...
that it originated from the bit of live rock you'd placed in the tank. Not
ID help with saltwater reef tank. - 5/7/2012
Can you please ID this small creature which I found floating in my tank? I have posted on numerous saltwater forums, but have yet to get a decisive answer. I counted about 20 of them on the day of the recording. My current inhabitants (coral
wise) are leathers, xenia, hammer, ricordea, candy cane, yellow polyps, and green/brown palys. Thank you very much for your time and dedication!
Spintheridae worm. Feeds on sponges and possibly hydrozoans. A not so common hitch-hiker but not one to be overly concerned with. Numbers will decline as it's food source dwindles.
James Lee Galecio
Hitchhiker ID/Worm ID 2/29/12
I got a piece of live rock with lots of tiny holes all over it and the
next day I saw some little arms coming from one of the
At first I thought it may have been a tiny brittle star, but then two
of the arms seemed to stretch much further then the others (and much
too far for that size of brittle star). Then I thought maybe some
sort of worm. It is a brownish color, but sometimes would look a
little purple (maybe from the actinic blue light). The longest I
saw the "arms" stretch is about 3 inches. The arms are
also almost hair thin, maybe half of a millimeter. Then there
were two to three other arms that stayed close to the hole this
creature was hiding in. The most interesting thing about this
little guy is the two longest arms
kept curling up into a spiral, almost making a cone shape from the
spiral. I would love to know what this neat creature is, and
I've been searching the web and on WWM for a couple of days now,
and nothing seems to quite fit the description.
<Very likely a Terebellid, a Spaghetti Worm.
Go here, scroll down to last picture.
James (Salty Dog)>
Re Hitchhiker ID/Worm ID 2/29/12
Thanks very much,
<You're welcome Paul.>
I have a clear spaghetti worm too on some other live rock! The
diversity of the ocean is amazing!
<Definitely so, very interesting for sure. James (Salty
Strange Inverts and writing 2/20/12
I have noticed some strange things in my reef tank. The first is most
likely a type of round worm.
<What is this ID based on?>
It very much like a strand of fine hair that is moving around in the
sand bed. Problem or not?
I know that most round worms are parasitic,
but I have no idea how I would even remove these from the system.
Second, a type of tube worm. The tube is white in color and I suspect
made of Calcium Carbonate. These are growing everywhere including the
glass and seem to be reproducing by at least 25% per day. I don't
think these are bad but I would like to know what they most likely
<... see WWM re>
I know pictures would help, but I do not have a camera that would focus
on something that small. Third, these small things that remind me of
capillaries. They are bright red and grow on the glass just above the
sand substrate. The are tiny and have filaments that seemed to stick
out from the tips. I also have noticed a barnacle on my Torch Coral. It
has been there for well over two months now and seems to be growing
like the coral.
When should it die? I only ask because I saw some people on the site
had sent in similar emails and they were trying to I.D. the animal.
Anyway, another thing I would like to know. I was looking on the site
and saw that filters can be converted into refugiums. I would like to
add a Mandarin Dragonet to the tank which is 55 gal. So I know I would
I know I have a good supply of Amphipods and Copepods but I believe
more are needed.
What would be best? Thanks for your time. Have a wonderful Monday. Or
Tuesday depending on when you read this.
<... exactly why are you writing? B>
"Worm" in the shrimp/snail tank
Can you help me identify this "worm" in the picture?
They appeared today.
I am wondering if they are harmful to the shrimp, snails, or me.
This is about the best picture I can get. Should I clean out the
tank and try to get rid of them?
<Mmm, how large is this one, others?>
I do a 10% water change every Saturday. I add conditioner to the
new water and a little bit of Iodide for the shrimp. I feed
Kent's Microvert, phytoplankton for the shrimp. Veggie
rounds, shrimp pellets for the snails.
They also eat the algae that is on the side of the tank. The tank
is in the sunshine so the baby snails will have algae to eat.
<Please read here: http://www.wetwebmedia.com/polychaewmcompfaq2.htm
Need to know size... not likely a problem. Bob Fenner>
full-size crop optimized
Re: Worm ID, in the shrimp/snail tank
They are the width of a hair and less than an inch long. They are
all white and they move like an inch worm.
<Hmm, likely some sort of worm, but there are phyla that fit
your description, image. Not likely harmful, deleterious... and
will "go" of their own accord some day... mysteriously.
Reef worm ID 1/23/12
Hey crew of WWM, I'm not entirely sure how to properly go
about critter identifications.
<Some day Lynn and I will get around to useful di,
Anyways I had this worm living in my Goniopora Sp symbiotically
I'm assuming for well over 2 years. My Goniopora recently
died a week back and the worm started to migrate eventually
ending where i took this photo of it. Usually I never get to see
it or be able to take a picture. I just want to know if it is
reef safe primarily to stony corals.
<I'd keep it... does look bilaterally symmetrical... need
to see, observe a good pic of the head itself... Doesn't
appear to bear parapodia on the segments. In fact, this looks
more like a very thin species of sea cucumber (Holothuroid) to me
than a worm. Cheers, Bob Fenner>
Trails in my live sand, Worms... --
We have 30gallon tank. Live rock and sand. A few damsels
<Mmm, what/which species? Not likely enough room here for "a
and a scooter Benny. We have some wormlike trails. Similar to what you
would see left behind by an earthworm. We notice them more in the
We have never seen a worm of any sort. Do you have any ideas?
<All sorts. There are literally thousands of species these might
be... brought in w/ your LR and LS... Not likely harmful. Read here:
and the linked files above. Bob Fenner>
Strange worms on glass -- 12/19/11
Good afternoon. Thank you for having this great site. I'm
hoping that you can help me.
This morning I noticed about 100 of these strange yellow worms
crawling all over the glass in my saltwater fish
only tank. Should I be worried. What do you think can be. Thank
<Mmm, appear to be some sort of flatworm,
"Planaria"... not really a worry, and will very likely
disappear on their own in time (due to predation, lack of
food...). Bob Fenner>
Worm id 12/8/11
My brother bought a green, round worm with feathers around its
After about an hour searching around the web and checking your
site, I decided to write and ask for an id and to ask what its
<Functions? In terms of what? This is not a worm, but an
echinoderm... A species of Sea Cucumber>
Finally, will it wipe his coral and livestock out?
<Could cause trouble if died and dissolved w/o detection. See
WWM re Cukes.
And a flame "scallop", oh joy
What Is This Wonderful Creature?/Spaghetti Worm ID
Hi kind experts.
I'm curing a batch of live rock, and I am overwhelmed with
the diversity of life appearing. I'm slowly going through
books and web sites to identify whatever I can, but this one has
me stumped. I have several holes in live rock from which numerous
tentacles sweep out. These smooth tentacles are at most a
millimeter in diameter, probably less, and as long as eight
inches or more! They are alternating bands of brown and blue.
They can completely retract into their hole and vanish, but
usually they are sweeping around the tank. Somehow this creature
(I think it's one being as opposed to a bunch of worms, but
of course I can't know for sure) builds a little white tube
like structure over its hole, about 3 mm in diameter and 5 or so
mm long. The tentacles come out the end of this tube. Once, a
clumsy snail completely knocked the tube off of the rock,
revealing the bare hole in the rock. The next morning the tube
was completely rebuilt.
Any idea what this is?
<Sure sounds like a Spaghetti Worm to me. Spaghetti worms
build elaborate tubes for themselves, either in the substrate or
in small holes/cracks in the rocks.
The worm secretes its own cement from glands on its belly, then
lines its tube home with coarse sand and small shell fragments.
They are harmless and can be beneficial in cleaning up detritus
and uneaten food bits. >
<You're welcome. James (Salty Dog)>
Re What Is This Wonderful Creature?/Spaghetti Worm ID
James - Thank you!
<You're welcome, Tim.>
I had run across spaghetti worms in my search, but the first few
pics I looked at did not look like what I had. But after you
ID'd it, I did a more detailed search and found a few that
look exactly what I have. There is a huge variety in
<Definitely so. There are many species of Spaghetti worms
which are included in the 8,000+ known species of marine
<You're welcome. James (Salty Dog)>
Identification of Marine Organism
I am in need of help in identifying the organism shown in the
attachment of this email. Also included is a map of where it was
found (off the coast of Massachusetts). From what I can tell it
is some type of sea worm, possibly a proboscis worm (Nemetera).
Any information that would help in the Identification of this
organism would be much appreciated!
<Does appear to be a Nemertean or Peanut Worm of some
sort/species. You'd do well to send this specimen to a
specialist at an east coast university in the field of worm
taxonomy. Bob Fenner>
Some type of worm?????
<Howsit Jorge, Como que va?>
These are the best photos I could get of this guy that I found
slowly (very, very sloooowly) slithering along my sump glass.
He has some pretty cool colors (red/brown and green) and some
thin tentacles on one end. Whatever it is, it is not very
coordinated and it has a very hard time moving.
<Mmm, yes... looks to be a specimen of the family
Terebellidae... an Errantiate Polychaete... See the Net, WWM
If by any chance I discovered a new species let me know so I can
name it "WetWeb" ;)
<Oooh, or Bobsbierasomething>
<Welcome, por nada, Bob Fenner>
PS - He is out of the tank so no hurry at all in getting
back....other than to kill my curiosity.
|Re: Some type of worm?????
Wow...that was fast!
PS - reef safe?
<Welcome and yes. BobF>
Worm ID 6/29/2011
I love your advice and willingness to help out people with
questions. Your honest answers are amazing.
<Thank you, much appreciated.>
When I was doing some aquarium maintenance I found this (see
picture) it appears to be a worm or larvae can you help me
identify it? It is about 2 inches long.
<Appears to be a Sipunculid, a Peanut Worm. In the future,
please do not send large photo files, resize to a couple of
<You're welcome. James (Salty Dog)>
Mystery worm ID 6/11/11
Hello WWM crew!
My name is Justin and I work at a local pet store. I'm
currently attempting to become our aquatics specialist.
So to start off we usually have people come in with pictures or
mysterious creatures from their RT that are found, so we can Id
them. Today however, a young lady brought in a worm that I
haven't seen in any book that we carry.
Its about 6 inches long when fully stretched out and has very
fine feather duster-like tip.
<? Need a close up photo of this>
Its almost zebra striped with black and white sections. The odd
part is that it retracts it's tip into itself like if you had
pulled a pair of jeans inside out.
I did see a submission that sounded close to what I have
presented you with, and you couldn't come up with an answer.
The reason why I have resubmitted you with this question is
because I have a picture and was hoping that it would be enough
to help you with the answer.
Mystery worm ID pic
<I suspect this may be a member of the Echiura, though I see
no example image via Google. Bob Fenner>
Re worm id... a vote for a peanut, nee Echiuran
Hi Bob & crew,
I saw this image today on WWM and think that it could be a peanut
worm - the description of the feeding apparatus and the striped
introvert would suggest as much.
<Is also one of "next" guesses. Thanks, BobF>
I saw what I thought at first was some type of macro algae, but soon
realized it is a worm of some sort. It looks like a piece of green,
segmented algae (somewhat thick...maintains its rigidness under high
with what looks like a pale orange balloon shape at the end sticking
out of the rock. It sort of looks like tiny orange balloon attached to
a thick green string.
<Not from this description alone, no. The segmentation points to the
Polychaeta, but... there are MANY possibilities. Need good
well-resolved images of the head, processes in particular>
I may be able to get a photo, but I'll have to figure out the macro
on my Canon first.
Loving what you do,
<Hopefully you'll one day be doing it with us. Bob
Black and white banded worm ID? 4/24/11
I've recently noticed another hitch hiker on the free piece of live
rock I received. It appears to be 2-3 centimeters or so, no legs, and
has 2 body segments per alternating black and white band (each colored
band is approximately square shaped, maybe slightly more elongated). It
is somewhat flattened, somewhat shaped by a bristle-worm with no head
or legs. There are no visible eyes or antennae, and both ends are
visibly the same, slightly tapering off.
I'm just curious as to what they are more than anything. What I saw
in the archives were white worms with skinny black bands, but nothing
exactly like mine.
If you can't ID it with that information, I will likely be able to
get a high resolution picture as they increase in size.
<How about here: http://wetwebmedia.com/pnutwrmidfaqs.htm
or one of the worm ID FAQs files above? Bob Fenner>