Xenia (pest?) and worm (ID, comp.)    2/20/09 Hi. I'd like to thank you for all your help. Today I noticed that one xenia colony has brown/black specks crawling all over it. <Mmmm> Just a few days ago a crab reproduced, so I wonder if it could be crabs eating away at the xenias. I say eating because some of the branches look like tiny parts are missing. If it is not tiny crabs, what else could they be? <Small crustaceans... or Nudibranchs... or... Need a much higher resolved image or two to tell. There are treatments for all... see here: http://wetwebmedia.com/LR,LS/HH%20PPT%20Pitch%20Cells/HHProsConsart.htm> Is there anything I need to worry about? We have two xenia colonies and only one shows the spots. I have attached a few pictures. <If it is convenient, easy to do, I would move the one showing these moving zots to another system... carefully lift it and place it in a container underwater... so that if this is a pest, predator it doesn't fall off...> When I was checking on the xenias, this yellow worm was stuck to the glass. I did some research and it looks like it could be a spaghetti or medusa worm. Can you confirm which one it is. Is it harmless in my tank? <Should be... it is almost assuredly a species of Errantiate Polychaete, see the Net re... Perhaps a member of the family Cirratulidae> I have removed it from the tank temporarily until I learn more about it. Thanks for all your wonderful help. Cindy salinity 1.025 nitrite 0 ammonia < .25 nitrate 2.5
ph 8.4
Alk 1.7 - 2.8
<Bob Fenner>

Saltwater Polychaete ID Question: Syllid Stolonization -- 1/19/09 Hello <Hi there, Andrew.> I've been reading over this site basically constantly since I set up my saltwater tank a little over two weeks ago and found many good IDs for all sorts of things that have popped up in my tank including a Collonista sp. snail who has now happily been returned to my tank. <Excellent, they're terrific little grazers.> A few days ago I moved a rock covered with Zoanthids and Palythoas because I didn't like its placement. I changed things around a little bit more and had more polyps open again but there was one section on one part of the rock where I still wasn't having any luck. From this rock I've already removed a Pycnogonid and a Nudibranch that was also eating some of my Palythoas <Yikes> so my next thought was that I either had another of either of those two I'd missed or that I had something completely new. Earlier today I saw a worm that looked like it was leaving the closed head of a Palythoa polyp <Uh-oh> but wasn't able to get a good look or picture. Later on though I saw it again and was able to suck it out using a turkey baster. I've attached a picture for some help with the identification. The worm is about 2 cm long. It also looks to me like there are a number of segments near the tail of the worm that could break off to form new worms - it looks like they have eyes and tentacles like the larger worm, especially on the back three segments. <Terrific observations. That is one bizarre but neat looking little creature, isn't it! What you have is a Polychaete worm (Family: Syllidae) that looks a lot like a species of Myrianida. Its more than unusual appearance is because it's in a reproductive phase. The parent reproduces asexually by means of budding a succession of attached offspring called stolons (process = stolonization). As you noted, the individuals near the tail appear more mature than those near the main body of the worm. When the juvenile on the end matures sufficiently, it breaks off and takes off! This process continues with the rest of worms on the chain. The really fascinating thing about these worms is that the generations alternate between reproducing sexually and asexually. Although the parent in your case is only capable of reproducing asexually, the offspring (apparently born all male or female) will reproduce sexually. For more information and photo comparison, please see this link: http://www.hawaiianatolls.org/research/CoML/features/polycheates.php > I figured it was either being a good bristle worm and cleaning up a polyp that had been killed by something else or it was the one eating the polyp. <Mmmmm, this is unfortunately one place I'm not going to be of too much help. I did some research and found Palythoa and Syllids/Myrianida mentioned together, but was unable to determine whether the worms actually preyed on the polyps or not. I can only recommend that you continue watching the colony for any evidence of further predation/pests -- and keep that turkey baster handy!> Any help will be appreciated greatly. Andrew <Your query was great appreciated! It's always a pleasure to see what neat little creatures appear in people's aquariums. Take care -- Lynn>

Worms 12/28/08 <Hello Chip. Minh at your service.> Found these in my tank appear to stay in sand and only have long tentacles protruding from the sand. What are they?? Are they helpful or harmful? <Based on the pictures provided, the worms appear to be Terebellid Polychaete or commonly known as "Spaghetti Worms." There is also a similar worm in the family Cirratulidae that is often times mistaken for the "Spaghetti Worm." Both the Terebellid Polychaete and Cirratulidae perform useful functions in aquaria by facilitating the consumption and recycling of fine organic debris such as minute particles of detritus. More information can be found in this excellent article: http://www.reefkeeping.com/issues/2002-06/rs/index.php.> Thanks. <You're welcome. Cheers, Minh Huynh.>

Re: Worms, Cirratulids  12/28/08 Thanks a lot, was not sure what to do with them. have 20 or more in sand and in/on rocks. <Have no fear. Rest assured that the presence of Terebellid Polychaete and Cirratulidae is a positive sign of a maturing aquarium. Cheers, Minh Huynh.>