Hitchhiker ID: Likely Amphinomid - 3/10/08 Hello, <Hi there, Sheye!> First I would like to thank you all for doing an incredible job on the site. Your site has provided me with answers to several of my question and given me hours of reading enjoyment. <Excellent!> Now my question. I recently purchased a total of 30lbs of Fiji live rock from my LFS. I was amazed to find so many hitchhikers (spiny brittle stars, common and blue-legged hermits, and several sponges). <Neat> But one of them I was unable to identify (pic attached). It looks like some sort of worm or Nudibranch but may also be a larvae of some sort. I doubt it is harmful <Likely not, especially at this size.> as most hitchhikers aren't and this one seems to munch on the algae. I would just like to know what it is. <Hmmm, I'd need to see more detail to be sure, but it looks like an Amphinomid/bristleworm, possibly in the genus Chloeia. Please see the photos at these links for comparison: http://www.wetwebmedia.com/polychaetes.htm http://calphotos.berkeley.edu/cgi/img_query?query_src=photos_browseimgs_invertebrate_sci&seq_num=226453&one=T> Thanks for your time Sheye <You're most welcome! Take care, -Lynn>

Re: Hitchhiker ID: Likely Amphinomid - 3/11/08 Hello again, <Hi Sheye> After looking at the links you provided. I have found it. In this link (www.wetwebmedia.com/polychaetes.htm) under Hermodice canunculata the last picture on the right. That is exactly what it looks like. <Yay! Mystery solved!> Thanks again!!! Sheye
<You're very welcome! Take care, -Lynn>

Critter ID: Eunice spp. Worm -- 2/15/08 Hi crew - and thanks again for the great resource! <Always a pleasure to share information with fellow hobbyists!> I'm attaching two photos of a critter I found in my live rock. <Yes, I see it. What you have is a polychaete worm in the genus Eunice, aka a "Bobbit worm" (after Lorena Bobbit - not going there!). Nice photos by the way, considering how quickly these worms can move!> The hole it's in is about 3cm wide, <3cm or 3mm?> and the critter pretty much fills the hole. <Thankfully, it looks like it's the length of the worm that's filling it up (at this point), not the width! I'm basing that on what appears to be a nearby Collonista spp. snail. Those supposedly top out at around 1/4" although most I've seen are around 3mm.> The front end looks like some kind of orange worm with antennae - the longest single antenna comes out of the middle of its head, <Characteristic in these worms.> ..then there are two sets on either side, with the lower set being shortest. <Yep. Terrific observations, by the way!> The lower part of the face appears to have flaps that remind me of walrus cheeks! <Coo-coo-ca-choo! Behind those 'cheeks' are some wickedly impressive jaws.> The back end appears to be shrimp-like. <I see what you mean. It does look a bit like the tail end of a mantis shrimp, but this little guy is all polychaete annelid worm.> I haven't determined how long it is, as I've never seen it completely out of the hole, but it did stretch its head out of the hole one time about 9-10cm and I didn't see the tail at all then, <Heeheee! Just wait until you find out what length some of these worms can reach! As if it's not a bad enough sign already that they're named after a woman who...well, never mind. To give you an idea, Bob has one in a jar that's eight feet long. Another fellow in Oregon has photos of a seven footer that was in his tank. The good news is that this is not the norm. I've had several of these in my tanks over the years and none have gotten very large or caused any problems. However, if I ever find a seven foot Eunice worm in my tank, the resultant scream is going to rival the infamous 1883 eruption of Krakatoa/Krakatau, aka the 'loudest sound ever heard by man'!> ..and didn't see any additional white bands either. <That's typical of the hitchhiking Eunicids I've seen as well. They usually have one light/whitish collar (or band), on/near the 'head' and that's it.> I seriously thought it was a worm until the photo showed the shrimp-like tail (it moves so fast I could never see it without the still shot). <Indeed. I read somewhere that these worms have been clocked retracting into their holes at speeds in excess of 20 feet per second. Now that's fast.> I haven't seen any pinchers or claws, <The jaws are tucked away until needed.> and I haven't heard any clicking noises either. <Nope, there wouldn't be any coming from these polychaetes.> It is very shy and spooks easily - darts very quickly back inside the hole, <Oh yes!> but also seems curious (or hungry) enough to peek out quite often. <This behavior should come in handy if/when you need to trap it.> I have searched every descriptive word for it that I can think of <LOL Let's see..worm with shrimp tail, shrimp with worm head...Shwormp! Sorry, couldn't resist ;-)> ..& looked through tons of shrimp and worm photos on various sites, but can't find anything quite like it. <Although I've made these worms sound like something out of a horror movie, they're not all bad. Some are scavengers that do a good job of keeping a tank clean. This is especially true of those species that stay small. Others, however, are decidedly predatory. They eat sessile organisms, small crustaceans, and are quite capable of catching/killing fish. Those jaws, combined with impressive speed, make for a very efficient ambush predator. Personally, I wouldn't trust any large Eunice worm in my tank. For that matter, I wouldn't trust even a smaller one in a tank with tiny gobies in it. Keeping the worm well fed would likely help to deter predation, but it would be a gamble. I have a Eunice worm in one of my tanks right now that looks very similar to yours. It's been in residence for about a year and a half. The diameter is about 2.5mm and the length is around 7cm. I've tried to bait/trap it, but have never succeeded. Thankfully, it hasn't caused any problems and I'm hoping it stays that way. As long as he behaves himself he can stay. The minute he approaches 1/4" in diameter, though, he's out of there! If I have somehow misjudged the size of the worm in your tank, and it is indeed 3cm (or close) in diameter, I'd recommend trapping and removing. There are many traps available on the market, as well as homemade versions covered at WWM and on the internet. If the worm is fairly small, you can either keep an eye on it and trap later if necessary, or try to get it out of there now. It just depends on what type of livestock you want to keep, or already have, in your tank. Heeheee, that and whether you're feeling lucky! For more information on Eunice spp. worms, please use WWM's search engine: http://www.wetwebmedia.com/WWMAdminSubWebIndex/question_page.htm See the following WWM link as well, about halfway down, for a photo of a similar worm: http://www.wetwebmedia.com/polychaeidfaqs.htm http://www.reefkeeping.com/issues/2003-04/rs/index.php > Thanks for your time. <You're very welcome!> You provide a wonderful service with a great sense of humor. <'Laughter is the shortest distance between two people'. Truly, it's a measure of how much we enjoy what we do here, and life in general. Take care, -Lynn>

Re: Critter ID: Eunice spp. Worm -- 2/15/08 <Hi Lillian!> Okay, so I'm from the US & screwed up the measurement <Heheeee! I thought something wasn't adding up! Not to worry - I've done it a time or two myself!> - the hole opening is about 3mm, not 3cm. And I forgot to sign the previous email. Sorry. Lillian B. :) <No worries, Lillian. Thanks for confirming those measurement for me. Take care. --Lynn>

 Nice pix! RMF.