Strange hitch hiker... not strange... tubeworms, sponge, SW& 6/19/08 Hello crew, Thank you for all your helpful advice I have learned so much from your website. I have a question about a hitch hiker in my tank. I bought some Chaetomorpha algae and put it in my two in-tank refugiums. I now have tube like worms growing on the glass around the refugiums and attached to the refugiums. They are white and grow out in a tube shape. They remind me of the siphon tube on a Nassarius snail. It appears to have a mouth at the end and it attaches to the glass with "branches" or "feet". They appeared very quickly and in large amounts. I have the tube worms with the hard shell that appear as tiny swirls on the glass and its not those. I reviewed all the worm questions and did not see a picture. It does not look like the pictures of aiptasia or hydroids that I have seen. If you could help in anyway I would be very appreciative. <It's really hard to say without a picture, but my *guess* from your description would be some kind of sponge.> My tank is a 57 gallon tall, Aqua Clear 70 filter, heater set at 77F, about 10 pounds of live rock, two seahorses, a skunk cleaner, one harlequin shrimp, two chocolate chip sea stars (one being eaten and one in the refugium for later), one feather duster, a toadstool leather coral, and several hermit crabs and snails. My tests are Ammonia-0, Nitite-10, Nitrate-0, PH-8.3. The only thing recently added was "reef bugs" and liquid calcium by Kent. Thank You for any help with this. I will try and get a picture but any ideas to look up would be great. <It sounds like a sponge, but who knows? I'll likely be able to help you a lot more if you can send in a photo. :-) Best, Sara M.>

Question, ID, no images  6/5/08 Hi WWM Crew, I have found each answer you have provided to others very helpful and use your site often! This particular "creature ID" I was not successful in finding any insight on and was hoping you would help me to the best of your knowledge!? <Is my habit> In this particular saltwater set up I house a Snowflake Eel, Damsel, Niger Trigger, Chocolate Chip Starfish, 2 Pencil Urchins, and several Crown Conches... and the unknowns! <Mmm, do keep an eye on the Odonus... may well sample the invertebrates here> The "unknowns" I speak of are flat white disk looking things that are suctioned onto the glass by a clear plate like suction cup. They stick straight out from the sides of the tank. I also noticed that there are many more of them along the side of a rock and they are all lined up evenly spaced. They are about the size of a nickel and do not seem to move anywhere. I only have base rock in this tank, no live rock so I'm not sure where they came from! If you could help provide some ideas for me as to what these are I would greatly appreciate it! Regards, Amy <Mmm, really need photos... perhaps these discs are Ascidian colonies... see WWM, the Net for pix... Bob Fenner> Mystery Thing'¦Holothurid? -- 06/05/08 Good evening! <<Morning now'¦Hello!>> I have a mystery guest in my 40 gal. reef tank that I can't find an I.D. for. <<Oh?>> I found it on the glass yesterday. It is about an inch long stretched out, purplish in color and covered in what look like tube feet. <<Hmm'¦>> It also had about five antennae-like things coming off of what I think is the front, but if I get too close they retract. <<From your description, this sounds like a species of filter-feeding Holothurid '¦a Sea Cucumber>> I am attaching picture I took, I tried to zoom in and crop it, but I'm not sure if it worked. <<There was no picture with this email>> I saw one of these creatures at Petco once, and was so curious what it was they let me have it, but when I put it in our tank it immediately shriveled up and floated under a rock. <<Typical'¦easily swept away by water motion unless given an opportunity to attach itself first>> Could it be a type of sea cucumber? <<That's what I'm thinking, yes>> I can't seem to find anything like it on your site. <<Though it may differ in color, have a look at the examples here: http://www.wetwebmedia.com/seacukes.htm >> Any ideas as to what it is? <<As stated'¦>> Thanks for your help, Amanda <<Quite welcome. Enjoy this animal while it is around'¦they generally don't do well in captive systems unless of some size and supported by a plankton generating refugium. But do check out the links at the top of the article page on Cucumber systems and feeding. Regards, EricR>>  

Unidentified organism  6/4/08 Hi there, I have had a 300 gallon set up for almost a year now; I have added a deep sand bed of about 5 inches some cured base rock that is coming along nicely.&I have added hermits and snail, along with two fish awhile back.&nbsp; I have two rapids pro filter/skimmers.&nbsp; Water parameters are great.&nbsp; I have&had no problems at all.&I have noticed that there is a lot of small bristle worms.&nbsp; Now i have noticed these clear long web type of organism.&nbsp; Having a close look along these long strands that are mainly on the walls,&nbsp;but have noticed they are on the rock and hermit crab shells as well.&nbsp; They have hydra type heads along the strings and are branchy almost like a web or varicose veins.&nbsp; I assume it is a hydroid, all help appreciated, thanks! <Impossible to tell from this desc.... please send along a pic... well-resolved... Bob Fenner>  

What's this? Need more information - 5/25/08 Hi <Hi Sue, Lynn here this morning!> I have a newly established marine aquarium and I'd like to know if I have a feather duster forming. I took pics but you'd never see it because they were bad quality, sorry. <Yep, small subjects can be a real challenge to photograph. You might check to see if your camera has a "Macro" mode. It's usually represented as a small flower icon (like a Daisy), either on a button or within the menu mode of the camera.> It's growing off the live rock, clear with a black sort of spot about a third of the way from the top. It's very small at the moment and I wondered how feather duster worms actually form. <It depends. There are many, many different types of what's commonly called a feather duster. Please see these links for more information: http://www.wetwebmedia.com/feather.htm http://www.advancedaquarist.com/issues/aug2002/invert.htm > I've researched this but can't find one at such a small stage. <How small is it - in inches or mm? Do you see a tube or feathery crown at all? I'm sorry Sue, but I just don't have enough information to go on. The good news is that what you're seeing is most likely harmless. Just keep an eye on it and if you're ever able to get a good photo, please send it along!> Regards Sue xx <Take care, -Lynn>

Freshwater Amphipods? -- 05/21/2008 Hi, <Hello Adam.> I was wondering if you guys could help me identify these little critters. <Sure will try.> They came in a shipment of feeder goldfish, possibly originating from Florida. For all intents and purposes, they look like brine shrimp crossed with clams. When they get scared, they close up in a bivalve-esque fashion and just look like little clams. But they will also swim around like little brine shrimp, and obviously have legs and eyes and antennae. <These are Ostracods aka Seed Shrimps. They are one (or possibly several) group(s) of Crustaceans with clam like shells. A internet search for Ostracods will bring up a lot of interesting facts, e.g. http://w3.gre.ac.uk/schools/nri/earth/ostracod/introduction.htm.> They don't seem to bother anything, so I assume they are filter feeders. Thanks! ~Adam <They are most likely beneficial creatures, only very few are parasites, most feed on detritus and decaying plants and animals, a few are predators. Ostracods are often used as fish food. Cheers, Marco.>

<Cool!! -Sara M.>