Unidentified creatures?
I've recently set up two small 10 gal saltwater tanks (in preparation
for larger tanks once some renovations are done). Anyway, in the tank
that that has plants, sand, LR, and a couple snails, I'm seeing these
really little "creatures" and I'm wondering what they might be.
They're at most 1/8" long and less than 1/16" wide. Their body is a
milky white, almost clear, with a brown stripe down the center. It
appears there are little antennae off each end, but that part is really
hard to see (you practically go blind trying to focus on them). << So far I'm thinking Mysis shrimp, but maybe amphipods. >> There
are no visible feet or fins.
If I had to guess I'd guess some type of worm or baby snail, but I'm
looking for a more educated guess.
<< Oh, wow that doesn't sound anything like what I guessed.  Do they move with a "tail" or with little pairs of legs?  Whatever they are, they are good to have. >>
By the way, your site is awesome - I'm constantly amazed at how much
effort you guys put into it for no apparent profit!
<< I know, my wife can't figure it out either. >>
Thanks,
  - Jay Harper
    New York
<< Blundell in the lab. >>

Unidentified Creature
I have noticed over the months a black creature swimming in my tank. It looks like a slug or snail without a shell, except it appears to be fairly flat. It tends to stay on the bottom side of the reef structure and moves about almost undetected. It has two antennae (or something that resembles antennae). It is probably 1.75 to 2.00 inches in diameter. I know it can survive pretty bad conditions because it has lived through 2 tank changes in which it was out of the water for some time.  I have also touched it out of the water and it almost felt like wet rubber. Any ideas what my unknown creature is? Is it a good friend or bad? <At first guess I would say its a Stomatella variata which is a wonderful creature and great for your tank.>
Also, I have a serpent starfish that does a great job cleaning up the tank.  However, I'm starting to think he's doing too good of a job. He appears to be preying on my fish while they rest. <Green serpent star fish are known for doing this. You don't mention which type you have, most of the others are fish safe.> Is this possible?  Do serpent starfish actually hunt for food that aggressively? The starfish is probably 10 inches in diameter with the head about 1.50 inches in diameter.
Thanks for any help.
Craig Walker

Re: misspelled/unidentified swimming creature
Please note that I checked for a "stomalla variata" and came up empty on
google and the WetWebMedia web site.  Can you please help?  Please see
below where you identified this reef member.
Thanks,
Craig Walker
<The name given you is wrong... the genus is Stomatella... please try this. Bob Fenner, who will send along>

Unknown Hitchhiker Hello!<Hi! MIkeD here>  I hope you're off to a great start on your weekend!<Of course!>  I found a new creature in our SW Aquarium last night that I am trying to identify.  I have checked on the FAQ and I can't seem to find one that is the same as our latest addition.  It appears to be a slug or snail coming out of a hole in one of our Tonga Branch rocks.  It does not have any kind of "free standing" shell that I can tell, just the housing shell of the Tonga Branch.  It is light brown in color and has at least 2 antennas, with a "lip" on the very tip of the creature.  It also has what looks to be strings or feelers coming from it.<I've tried opening the photos you sent and am not having ant success, but if those "strings" are on the back, either in the middle or covering the whole back it's some type of nudibranch>  I've checked the tank at night several hours after the lights went out to see if he was "out and about", but was still in his Tonga Branch home.  I have attached a couple of pictures if they'll help.  Sorry about the photo quality, it's hard to take pictures of the smaller animals.  I would say that this creature is about the size of a pen cap.  I have been able to ID most of the creature that have come along with our live rock from your FAQ, I just wasn't able to find one that looked like this guy.  Any ideas if he's a good hitchhiker or should he be evicted?<Nudibranchs are predators,  most often on anemones or some SPS corals. occasionally on each other. If you have a reef tank, you'll probably want to remove it, but if it's a FO or FOWLR it should be just fine. I had a pair of pink ones come in the same way and enjoyed them enough that I started providing live anemones for them> Also, I'd like to know if it's safe to use RO/DI water with our red eared slider turtle.  We recently started using the RO/DI water with our SW Aquarium and like the results I'm just not sure if it would be okay for our turtle.< I'd probably suggest against it, with dechlorinated tap water being a much better choice. The water itself is often a source of trace elements and electrolytes. both of which are essential for it's well being>   Any and all help is very much appreciated!  Thanks so much for your time and effort!<Our pleasure> Newer hobbyist, Christi Moore

Critter Identification 7/25/04
Hi.  I started a 75 gallon saltwater aquarium last November, went through all the evolution headaches and finally got rid of my algae problems.  I still wasn't having any luck with fish due to ick so I gave up on the  fish and decided to just enjoy my inverts and live rock which is  thriving.  <Sorry to hear you gave up on fish!  Reputable suppliers and faithful quarantine are the real tricks to success.  I am glad to hear that your other friends are doing so well!>
I also added some Caulerpa and my tank seems to have developed its own little self perpetuating ecosystem with minimal maintenance. As a matter of fact it has sprouted all sorts of life forms.  Baby snails, some sort of bug-like creatures who hang out on the glass, tons of feather dusters and some new sort of macroalgae. <It is remarkable what diversity can develop with good habitat and freedom from predation!  When you do go back to keeping fish, some of this will be lost, but your tank will benefit from allowing these critters to get a head start.>
The thing I am really fascinated with though are some little creatures that are swimming in the tank.  They are about 1/8 inch long but are growing, they are transparent and look like miniature humpback minnows or tadpoles with big black eyes and whiskers like a catfish.  I know its a long shot without pictures but I was wondering if you might have any idea what they are.  They are too small to photograph with my piddly camera.  Any ideas? JJ
<I am stumped, but it is a good bet that they are larvae of some kind.  Please reply with list all of the critters in the tank that may have spawned.  Perhaps you could include a sketch?  Also, eggs or larvae can be imported with shipping water or attached to substrates.  If they survive, they should become more identifiable as they grow.  Best Regards.  AdamC>

Critter ID 7/29/04
Thanks for replying.
I have red legged crabs, king Nassarius snails, orange sand sifting snails, turbo snails,  a Hawaiian feather duster, a mushroom rock, a Condylactis, a coral banded shrimp, a sea hare and a chocolate chip starfish (sequestered in a critter box). None of these seem likely candidates to me. At least the little swimmers  don't resemble any of these. They look more like baby fish. The tank has been fallow of fish for over two months.
<I agree that none of the above seems likely, but do keep in mind that larvae rarely look like the adult.  Most do look at least a bit like what you are describing. Most shrimp and crab larvae (common to observe in captivity) look rather like little commas. and swim with a flicking motion.>
I don't have a scanner so I can't do a sketch...not that I would be able to draw anything recognizable anyway!  They just really look like transparent tadpoles before they get legs and the tail comes out of the lower portion of the body. I do hope they survive because I really want to see what they become.  Then  I have the various things that live in/on the live rock (worms, sponges, polyps, copepods, arthropods, etc. My dead rock has now also become live.
At this point I am almost afraid to do anything different because I don't want to upset the balance.  I quit using carbon in my filter and went to Purigen. Since that time my water quality has improved immensely.<I am not familiar with Purigen.  By what criteria has your water quality improved?>
I don't feed any food except the occasional piece of scallop to the anemone because the tank is almost surely full of some sort of plankton or other.<Those critters do need to eat, but without fish, the small amount of food entering the tank is probably fine.  You anemone will expel left overs that will feed the critters.>
Mostly, I just keep replacing evaporated water. My specific gravity is about the only parameter that is outside the usual recommended range at .026, which I know is high, but with the flourishing of life that is happening I am afraid to bring it down. Fish probably wouldn't do too well in that range. <Not high at all, in fact 1.026 is what I recommend for all marine aquaria and is right about the world average for sea water.  Some areas like the red sea are even higher.>
Thanks so much for your input.  I was ready to quit but since I quit obsessing so much about it, it has become an amazing journey  JJ.<Glad you are hanging it!  It is a fantastic journey!  Let us know if you discover the identity of your mystery critters, but don't be disappointed if they just disappear.  Most larval organisms don't acquire enough food in aquaria.  Best Regards.  Adam>

Syconoid/Sycon Sponges 7/20/04
First of all I want to tell you that your site is incredible. Keep up the great work.
<thanks kindly>
I am writing because I need help identifying a critter in my tank. They look like a little white puff of cotton.  Most of them
are cylindrical with a small tube like structure coming out of the top. They range in size from about the size of a pencil lead to the size of an eraser. They don't seem to ever move from what I can tell. They also seem to like dark places. Most of them are in the sump of my wet dry but there are a few in my tank on the underside of rocks. I would appreciate any help and to know if this could be a problem. Thanks a lot for your time. ~ Ryan
<I am sure that these are Syconoid sponges... please do type in the word "Sycon" on our index page (wetwebmedia.com) and do a google search for info and pictures in our archives on the subject. Best regards, Anthony>

White Worms
Hello <Hi Bradley, MacL here to try to help.>I recently setup a 4 ft marine aquarium it has been running for four weeks water is perfect but I have found miniature white worms on the inside of the tank they are crawling all over the glass, what are they? <Could be a lot of things. Let me suggest you take a look at this page http://www.wetwebmedia.com/worms.htm, and for worm identification http://www.wetwebmedia.com/wormidfaqs.htm.>

White circles
I have these white circle type things building up on my glass. What are
they? They are hard and will only come off if I scrub the glass with a
scraper or a finger nail. They just fall off and land in the sand.
Thanks
Geoff
<These are very likely small tubiculous (tube-building) polychaete worms (sort of like featherdusters), that make their own homes out of calcium... not harmful, will likely "cycle out" with other organisms predating them, other foodstuffs (their filter feeders) dictating other dominant life forms as your tank matures. Bob Fenner>

White Spots on pole ?
I am sorry to bother you, but I had a question. I was just about to clean
out my fish tank and I came across some white dots on my pole leading into
my fish tank. they are on top of the algae. I was wondering if that was
anything to be worried about? Is it another type of algae? or what. It is
just little white dots, but about the size of a pens tip. Can you help? I
don't know if it is deadly or what. Kat
<<Hello. Is this a freshwater or saltwater tank? Which pole are you referring to? I don't think they are harmful as long as they are not attached to any fish :) -Gwen>>

Mystery Critter ID What's up Crew!<<  Just typing away. >> I found this critter clamped onto my Hammer Coral's skeleton.  It took mucho strength to pry it off.  It opens up split from the middle and sticks out a pinkish tongue-like flesh. << Haven't seen the pic yet, but already sounding like a bivalve mollusk. >> It's pretty alien looking IMO.  I'm attaching two photos top and side views.  Really appreciate if you can help me ID it and let me know if it is predatory towards any of my corals or inverts. << Well it appears to be some sort of Bivalve.  Looks cool.  Unfortunately with about 14,000 species of Bivalves, I don't think I can be much more descriptive.  I'll bet it isn't predatory and is a great addition to your tank.  This type of biodiversity is exactly what you want in a reef tank, so I say keep it.  Please continue to watch it, and if it on a coral let us know.  Otherwise keep it growing (it needs live rock, and that's about it) and please take pictures again.  Looks pretty cool, and I'm sorry I can't identify it. >> Thanks a bunch! Roy <<  Adam Blundell  >>

Mystery growth
Greetings Crew!
I have something growing in my 125g FOWLR I was hoping you could id for me. << I can't ID very well, but can say it looks beneficial, and it looks like sponge. >> The particular rock in question has had some small (no larger than 1/2" squared) white/clear "fuzzy" growths since I bought it about a year ago. In the past couple of months the growths have combined and now cover about 1/4 of the rock, and have also taken on a yellowish brown color with some projections off the rock. << It looks like sponge. >> It is not as darkly colored as the pictures appear.
I want to say it appears somewhat sponge-like. I am concerned that it may be an indication of degrading water quality. << Just the opposite, I would be pleased to see it growing so well. >> All tested parameters are great: ammonia and nitrites always 0 and nitrates never above 5ppm. I have no other nuisance algae or Cyano, and just a tad of brown diatoms on the sand. Temp is 81-82 steady and there's about 1200gph flow in the main tank. 50g Sump contains a 20g fuge with LR and various Caulerpas, also a Tunze skimmer. I do 15-20g changes 3 times a month, feed the fish the equivalent of 1 cube various frozen goodies (sponge heavy and Mysis...never brine) and about 4" squared of Nori sheet daily (soaked in Selcon about 3 times weekly). They all seem to be in the peak of health.
Inhabitants:
3" Passer angel
6" Double Barred Rabbitfish
2.5" Yellow Tang
1" Fiji Devil Damsel
5 - 1" Talbot's Damsels
Have I crowded the tank? Do I overfeed?
I am upgrading to a 240g tank next September when I move into my new house...was thinking I would be ok till then. << Watch your Passer Angel, he may eat it.  Which is fine, algae is great for most ornamental angels. >>
Thank you very much
E
<< Keep it growing. >>
<<  Adam Blundell  >>

White dot stuff in marine tank
we have a 30 gallon salt water tank.  in this tank we have live rock, a purple tip anemone, a coral banded shrimp, a chocolate chip star fish, a blue star fish, s feather duster and an anemone crab.  up until a month ago we had clown fish,  a puffer, sea beta, a striped catfish and a flame angel.  we lost the flame angle.  all the fish have been quarantined because we have this white dot stuff that sticks to the tank walls and floats through the water.  it seems to not want go away.  first of what is it? and second how do we get rid of it?  thanks for any help you might be able to give
Marianne
<Wish you had a small microscope like the Mattel-Intel QX... and could take a closer look. Very likely these are some sort of small crustacean species... not harmful, no need to "get rid of"... will cycle out by themselves in time. Bob Fenner>

More unidentified critters... no pics II 6/10/04 I
Thank you for your prompt response to my previous question.  
<very welcome my friend>
It looks like I will be removing these creatures from the tank tomorrow, although don't have a clue yet how to accomplish this.
<napalm and a flamethrower get my vote <G>>
Well, another unusual "thing" seems to be evolving from my LR, and once again, having gone back through past Q&A's I see no reference to anything similar.  Specifically, there is about 1 inch clearance between the live rock and the back glass of my tank.  In looking into that space from the side of the tank, I observe something which appears spherical, about  1/4 to 3/8 inch in diameter, shiny and a dark "muddy green" in color.  Almost a dark khaki green.  About 40% of it appears embedded in the rock, with the remainder visible (from one side).  I suspect that this "thing" may be an egg of some type.  Any ideas?  
<the description is very general... it could be so many things. But perhaps it is a cryptic bivalve clinging to the rock. You really do need to get some books and participate in a local aquarium club if these micro-organisms fascinate you as they do me. Else, please send clear full frame photographs of the organisms in question for us to be able to help you>
Again, thanks for your response to my previous question, and thank you for publishing such a great and informative web site.
<thanks kindly, Anthony>

Unidentified Critters... stranded hydroids 6/9/04
I have had a 30 gal reef tank for about a month now.  I have 45 pounds of live rock and 3 corals so far.  Also some snails, hermit crabs, a sand star and a blood shrimp.  No fish yet. I have been diligently checking chemical balances and everything seems on target.  In the past few days I've noticed some unusual critters appearing on the glass and live rock.  I've seen several very small snails (1/32 inch) which began appearing before I introduced snails into the tank, so I assume they've come from the LR.
<yes... indeed> In the past week I've noticed several translucent
critters on the glass which move like snails, have no shells, are about 1/8 inch long and have 2 points at their back end.
<sounds like a flatworm... the little milky white ones prey on copepods. All are harmless>
From reviewing other questions responses you've given, I've identified them as flat worms which are not harmful.  
<Ah, BINGO- you win the hairy kewpie doll! Very glad to hear you in the archives :) >
However yesterday I've noticed a new critter which, in reviewing your Q&A's, I cannot identify.  These seem to have emerged within the past day.  They appear to be long white strands with
a single row of "hair" (1/16-1/8 inches long) on one side. (Almost like a 1 sided long skinny white feather.)  
<Yikes... I recognize it already. It is a very distinct description. Your creature is a fiercely stinging hydroid. Do remove it... it will sting you and your animals alike>
They seem to be about 2-4 inches long and appear to emerge from a jelly like polyp on the rock. They drift with the current from my power-head, and periodically retract back into the polyp.  I assume that they are "netting" micro-organisms, then "reeling them in" to be consumed. These strands are so thin that they
are not visible unless you are very close to the glass.  Any idea what these things are?  Are they dangerous to the other life in the tank?
<yes... do be careful. Best of luck, Anthony>

Small snail slug things: Acoel flatworms 5/27/04
Good Morning. Just sending out a photo this time to see if you can ID these little slug things.
<they are acoel flatworms (AKA red or rust/brown Planaria). Do a keyword search with these terms of our website and beyond to find details and solutions to reduce them>
Came with my yellow polyps, and are growing rapidly. Are
they good or bad?  
<simply a nuisance if/when they bloom. Strong water flow and aggressive skimming alone can help to reduce them>
Thank you for your time. Thanks, Daniel
<best regards, Anthony>

Alien Landscape
>Dear Crew,
>>Dear Querier..
>Firstly I must congratulate you all on such a good source of information.
Very impressed with this website!
>>Why, we must thank you quite collectively!
>I have one question for you today. I have a Marine aquarium, Eheim Professional external power filter, Aqua-medic protein skimmer and a UV Sterilizer. I have around 8 kilos of Live Rock mixed with about the same again of normal Ocean rock on a bed of coral sand.
>>I wonder, in what size tank? No matter.
>I have a Clark's Clown Fish, a blue cheeked Goby, a few Green Reef Chromis, a
sand sifting star fish..
>>Archaster typicus? If so, a detritivore of good worth.
>..about 9 or so hermit crabs and a couple of Turbo snails. It has been running now for around 3 months, all seems fine and the livestock appear OK, water tests return recommended readings etc.
>>Ah, shame, you skip the good stuff - actual readings! But again, on to your actual question which leads to no worries, but an observation you may find surprising.
>On the whole, we think it's a healthy tank.
>>Right, as it would appear.
>I have noticed though, a considerable amount of tiny creatures on the rocks,
they are too small to get a good look but they look sort of "beetle" like
but are translucent. They must be about 1 - 2mm in size but the numbers are
increasing and they are all over the rocks.
>>Hee! The copious "pods"! This is very good, very good indeed. The "pods" are of various types, to be sure. Copepods, amphipods, isopods, all pods. <cut to "Invasion of the Body Snatchers", dog with human head, ew>
>Does anybody know what these creatures are?
>>Aye, mate, but only roughly. We'd need microscopic slides and reference books to make exact identifications. 
>Are they good or bad for the tank?
>>GOOD! QUITE GOOD!
>Any info appreciated.
>>They are food for many types of fishes, and are an excellent demonstration as to the efficacy (or lack thereof) of that U.V. sterilizer. <insert wise winky here> Personally, I don't care for U.V. use on any system resembling a reef, not effective in disease control in my opinion, and if so, then would also kill many of the tiny creatures that are indeed desirable. It seems that your unit does neither.
>Many Thanks.
>>And now begins your era of discovery with the alien landscape you've created. If any of the creatures begins sporting a crown and demands homage, send it/them my way, I'll set them straight. Marina, Maiden of the Seas (a.k.a. "sea monkey") 

How to identify items 5/24/04
Hey Guys, Thanks for all your help. Internet is great for information when you know the answer. Is there a book that would help Identify the obscure like the following?
<There sure is! Do look for "Reef Invertebrates" by Anthony Calfo and Bob Fenner. In my opinion, it is the best hobby resource available for this purpose.>
I have several white things growing in my sump on the sides of the glass. They are too small to photo so I'm attaching a drawing. The look kind of like a tube worm but they don't move or retract. The body is spongy. Any ideas as to what they are? Kevin
<They are in fact sponges (probably Lucella sp.). They grow quite prolifically in aquaria and are harmless and beneficial. Enjoy the diversity of life! Best Regards, Adam> 

Critter ID: critters smaller than copepods 5/21/04
Also, we have Copepods in our tank that appear randomly. I also noticed that there are smaller (than copepods) white worm-like critters stuck on the sides of the acrylic with the copepods, they seem to be longer & move about more squirmishly than the copepods that sort of jump. They are grouped around what appear to be small eggs in groups of about 10-15 (again, small & white, but round little eggs). They are much smaller than the copepods as I have to look at them with a magnifying glass & they do not appear to have any sort of legs or "antennas" as I call them like the copepods. Any ideas?
<alas, no... you mention worm-like and copepod in the same description and those two are incongruous. Frankly, I am sure they are harmless. No parasites visible to the naked eye will congregate on the glass/surfaces>
Wish I could get you a picture, but they are entirely too small. Have only noticed them on the sides of the tank & my fear is that this is some sort of parasite.
<they are harmless plankters, no doubt. Do look at some of the published articles from Dr. Ron Shimek online perhaps (keyword search on Google search engine) for more perspective on micro-organisms. Anthony> 

Critter ID: critters smaller than copepods II 5/21/04
Hello Anthony! Nice to have some peace of mind that these are not parasites! I noticed that the eggs have now "hatched". Don't seem to be bothering the fish at all. You all are so helpful! Thanks very much for the response.
<very welcome my friend>
I will look to the articles you referenced. Happy Friday!
<we also have a chapter on microcrustaceans in our "Reef Invertebrates" book. Best regards, Anthony>

-Cryptic growth ID-
I am having a hard time identifying this pink growth on my live rock. It is very thin across the rock, translucent really. Each patch of pink seems to have a several "mouth points"; this makes me think sponge possibly. Hopefully it's a good sponge Please tell me it's not bad! <There's no way this growth is bad, but from the picture and description it's difficult to say whether it's tunicate or sponge colonies. Either way, its a sign that your tank is coming along well and has a diverse population of critters! Enjoy! -Kevin> Any info on this stuff would be great! Love your web site....it's the best! Thank you Josh.

Copepods...
Can you help me??  I have a question.  I see tiny white dots on my tank wall. They look like little white fleas or similar.  they also move around.
What are they...are they bad...what should I do?
<They are likely just harmless copepods that some of your fish may even make a snack out of.  You can find more info on them on our site:  www.wetwebmedia.com. Cody>

I got worms - 4/28/04
wow....quick response....I forgot to ask you a question on my previous email.  I have some white translucent hair like filaments growing all over my live rocks. They look like webs.  They can only be seen up close but from far away are not visible. They are about half a centimeter in length. They wave with the motion of the currents provided by my powerheads. Do you have any idea what they are and will they cause havoc in my tank??? <Won't cause havoc. Please look here: http://www.wetwebmedia.com/wormidfaqs.htm check the other worm id links above as well> This is a poor description but hopefully you have seen such things attached to the surface of the rocks. <Again, I would like to remind our readers to please do your best to search the FAQS and articles before emailing. We are so inundated with questions that it will help much to search before asking. Thank you for making this the best "Wet" website on the planet!. ~Paul>

Mystery Creature?
Greetings oh wise WWM crew!
<Wise...Well- I've been called a "wise a_ _" , but I dunno about a "wise one"! Thanks for the compliment, though! Scott F. here today!>
I have this critter that I've only seen twice and it won't show itself enough to get a photo. It's obviously a live rock hitchhiker because I sure as heck didn't add it. The first time I saw it was inside a large hole in the rock. This time, it partially exposed itself and seemed to be feeding right after I fed the other inhabitants my meaty/fleshy concoction. I'll describe it the best I can and see if it rings any bells. It is all white and is about 1 1/2 inches in size. It seems to have multiple "seastar-like" arms, which are covered by spines. It has visible eyes which reminded me of those on my turbo snails. It's mouth area is visible in front of its' eyes, and when it was feeding, it reminded me of the legs on my cleaner shrimp (moving a thousand MPH). It wasn't exposed long and went right back into the rock (seems to move rather slowly). I read about urchins/seastars, but aren't their mouths on bottom of the animal - and they don't have eyes so to speak do they? Just hope it is not something that is going to end up preying on my fish at night - most all of my stock is small. Thanks again for all your help!
<Well, Melissa- you seem to be describing something like a brittle or "Serpent Star", but, then again, it's possible that you're looking at something completely different! To be honest, I think that a photo would be the best way for us to ascertain just what this animal is. Do keep trying to get that pic- and hopefully, we can give it a shot for you! Good luck! Regards, Scott F.>

Critter IDs 4/12/04 
Hello Crew, 
<howdy> 
I have attached a picture, sorry it is not clearer then it is, but I have this purple growth on some live rock I just bought and looks like a sponge maybe? there are a number of little purple nubs all over the rock as well. 
<the picture is a wide frame shot of a piece of live rock... yet I am, not sure what it is you'd like IDed here my friend. Do try to take closer shots or perhaps place markers on the image to guide us to> 
also there is some sort of white growth at the base it is almost shaped like a polyp but its hard, any idea would be great as I searched the web and can not find anything that looks like this 
<in this shot I see what appears to be red/purple sponge... encrusting around a white (exposed?) corallite of a solitary cup coral. Numerous other filter feeders in evidence in the rock. All fascinating stuff :) We do document many such organisms in our new book "Reef Invertebrates". Online, Dr. Ron Shimek has written many articles on micro-organisms, Rob Toonen too. DO some keyword searches f their names for articles. Best of luck! Anthony>

Seeing Spots, Not High
I recently purchased a salt-water tank and now there are these small white dots growing on the side of it. the snails aren't eating it, they are just ignoring them. is this a worm or some type of bacteria? please help 
<These small white dots could be quite a few things. Without a picture it's difficult to tell. Keep in mind that everything I suggest is just guessing from the term "white dots" on glass. Spirorbidae snails often look like "white dots." These are snails which form calcareous tubing which is often observed as a spiral shape. These are quite small, usually around 2mm in length.  You could also be seeing copepods. These are small shrimp-like invertebrates which can often be seen on the glass and rockwork. However, these invertebrates will move around the glass. If these dots are stationary, I would eliminate the possibility of copepods. It would be good if you can get a picture of these dots. Without an image it's very hard to say what it is. Hope this helps, Graham.>

Tiny Critters (3/31/04)
<For future reference, please capitalize the proper noun "I" and the first letter of sentences. We post all queries and replies on our site permanently an want them as readable as possible. Our volunteer crew will have a lot more time to answer queries if they don't have to proofread them. Thanks.>
  Hi, I recently discovered that there's a new kind of animal that has appeared in my tank. they are very small (smaller than half a mm), and they're white. they seem to gather wherever there is algae on the glass. I was wondering if you knew what they were and if they would be harmful to my coral Catshark? thanks for any help.
<Almost certainly some sort of harmless microcrustacean such as an amphipod or copepod. I would not worry about these. Search these terms on WWM for more info. Steve Allen.

Mystery in Tank
<please resend your picture unzipped and as a downsized web-courteous jpeg (a few tens to a couple hundred kb maximum). Thanks kindly, Anthony>
Hi!  I was wondering if you could help me identify these mystery things that came with some live rock I bought at my LFS.  At first I thought it was Aiptasia but it doesn't look like any of the pictures I've seen of that.  It appears like a translucent flower, it retreats back into the rock when startled, but I do not see a tube.  Thanks so much in advance! Amy

Resizing images for ID 3/28/04
Thanks so much for the quick reply.  Unfortunately I had to call someone over to help me send the attachments I did send.  I tried for 3 hours this afternoon to get them sent in JPEG form and never could get it to work.  
<Awww... I do appreciate your efforts. Hmmm... this may seem daft/obvious... but do you have some sort of image editing software loaded on your pc like Photoshop or Photosuite? If so, you go into the toolbar (sometimes under "view") and click on "size" and there you can reduce an image from hi-res to low res for web sharing (400X600 max for example)>
We got this computer new in January and there's still lots that seems impossible to work.  
<no worries... all a learning process>
I think I have a feather duster of some sort, I called a bunch of people and that's the general consensus (sp).  I just set up this aquarium a few weeks ago and got my first live rock today so I was in a tizzy when these things started springing up on my rock.  But they're cute and fun to watch so I'll just keep watching and if they start spreading I'll get concerned.  
<no worries likely at all. Such growths only become a plague is the system has a nutrient export problem (lack of water changes, overfeeding, overstocking, etc)>
They don't have anything in the middle, they open up like a daisy and then shoot down into the rock when disturbed.  Thanks so much for getting back to me so quickly, sorry about the attachment.  I don't know if I'll get the computer figured out! Hopefully I will have better luck with my tank!  Thanks again! Amy
<wishing you the best! Anthony>

Sycon sponges ID 3/28/04
Dear Bob and Wet Web Media, My friends at Elmer's Aquarium in Monroeville have told me that you and Anthony are the foremost experts on saltwater aquariums and in particular coral. I just bought a  copy of "Reef Invertebrates"...awesome book.  
<Thanks kindly... Anthony Calfo here>
So here is my question which Elmer's could not answer.
Last week I went away on an eight-day vacation. When I returned, I found a one-inch diameter growth on my four-month-old Fiji rock in my 150 gallon saltwater aquarium. The growth looked like a ball of cotton or a spider egg cocoon. Doing a water change, I think I dropped a shell on the growth. In any event, the next minute when I looked at the aquarium, there were 30 miniature spores (?) on the back wall of my aquarium and high above the growth on the trickle bio system. I think that the growth was punctured by
the shell and shot spores out.  Any ideas?
<your picture reveals many harmless Sycon sp. sponges (the dirty white pillowy tufts). Their presence in excess indicates a nutrient problem if they get out of control, but generally are a nice compliment to the tank's diversity>
I attached two photos: one of the shrunken growth and the second of the spores on my trickle filter. Please call or email me with your thoughts. The pictures were the best I could do with the equipment I have. Sincerely, Wayne Dollard
<no worries... all good. DO use the terms "Sycon" or "Syconoid" in a keyword search (Google search tool on our homepage) of our archives for more pictures and information. Kindly, Anthony>

Sponge ID 3/28/04
Thanks for the quick reply Anthony,
<always welcome my friend>
I have tried to attach the cocoon photo again.  I looked at the section you linked but didn't see anything like it.  
<agreed... although this pic is not clear, it clearly is not a Sycon to me. Yet it is a sponge>
It is a much lighter color in real life and the hole looks like it has a smooth lining to it.  Almost like a tiny straw was used as the lining. I am constantly amazed by what shows up in my tank on a day to day basis.
<the wondrous beauty of nature. Anthony>