FAQs about Sea Cucumber Identification 1 Related Articles: Sea Cucumber, Marine Scavengers, Sand Sifters Related FAQs: Cuke ID 2, Cuke ID 3, Cuke ID 4, Cuke ID 5, Cuke ID 6, Cuke ID 7, Cuke ID 8, & Sea Cucumbers 1, Sea Cucumbers 2, Cuke Behavior, Cuke Compatibility, Cuke Selection, Cuke Systems, Cuke Feeding, Cuke Disease, Cuke Reproduction,

Identification Please: Rock-Dwelling Cuke -- 11/23/09 <Hello, Lynn here this evening.> I was hoping you could identify this thing for me!!?? <I'll sure try!> Attached is a picture of it at night feeding. It lives inside of the rock and feeds just like my sea cucumber. <For good reason! It's a neat little rock-dwelling Sea Cucumber/Holothuroid. For more information/photos, please see the related FAQ's at the following link, especially 'Anemone Id? Nope, It's A Cuke! 8/10/07': http://www.wetwebmedia.com/cukeidfaqs.htm Terrific photos under the FAQ titled 'Hitchhiker ID: Rock-Dwelling Sea Cucumber -- 6/17/09': http://www.wetwebmedia.com/cukeidf4.htm > Hope it is not bad!!! <You should be okay unless it's a large Cuke in a small tank. Please see the above links for more information related to risk. Take care, LynnZ>

Unidentified Sea Cuke 8/3/09 Good evening Mr. Fenner, <Kay-M> My boyfriend and I bought this sea cucumber from a local aquarium. The sales associates there told us it was a sand-shifting Cuke. <Mmmm, no> We put him on the sand after acclimation, but he slowly moved to the top of the tank where the water level was and towards the back of the tank where it was darker. He even moved onto the back of the filter. My boyfriend has had to move him once because we changed the filter. Once again, he placed him on the sand, but not so close to the glass as we did initially. He has since moved up the LR and is settled next to some xenia. I have been researching him for some time and don't believe he is the Red Cukes of California and thought he was a red footed sea Cuke. The difference between ours and the latter is that the feeding tentacles are cream in color, not black ( I don't know if that makes a difference) and the tube like tentacles coming off the body of the Cukes are fatter on mine than on the ones of the red footed sea Cuke (from the picture I have seen). Our cucumber looks more fuzzy and soft, in my opinion. Any insight that you can give on identifying or where to find more information on this sea cucumber would be greatly appreciated. The only thing I know for sure is it is not a sand sifter, it in fact, seems to despise the sand. Thank-you, Kay-Marie <I think this is likely Pentacta pygmaea... Bob Fenner>

Please help to ID: Sea Cucumber -- 6/1/09 Hi, <Hello> I happened to see this tube worm (I think so) opening up one day from my LR. Tried searching through but unable to ID what this is. Its color is black hairy, tipped with luminous yellow dots on its flesh. <Pretty> Can you help to identify what is it? <It looks like a sea cucumber/Holothuroid of some sort.> Is it harmful? <Possibly. When a sea cucumber dies or is stressed, it can release a toxic substance into the water, sometimes killing the tank's inhabitants (aka the dreaded 'Cuke nuke'). It just depends on the tank/Cuke size, filtration and species. Some Holothuroids are more toxic than others, and unfortunately I can't ID yours to that level. However, it looks like your individual is fairly small, and hopefully stays that way. Unless you've got a very small tank, chances are good that you'd be okay. This is particularly true if you know the Cuke is in trouble and either remove it and/or employ good skimming, water changes, and carbon use. Please see the following links for more information: http://www.wetwebmedia.com/seacukes.htm http://www.advancedaquarist.com/issues/jan2003/invert.htm http://www.advancedaquarist.com/issues/nov2002/invert.htm > Thanks. <You're very welcome. Take care, LynnZ>

Good eye Lynn. RMF

Hitchhikers: Pistol Shrimp, Brittle Star, Possible Cowry -- 4/30/09 Hi, <Hi there, Steve.> Just wondering if someone can help me ID these critters I found on my Liverock? <I'll sure try!> Just wondering if they are reef-safe or not? <That term can vary, but I define reef-safe as posing negligible risk to corals, fish, clams, and most ornamental shrimps. The first photo is of a Pistol Shrimp -- mostly reef-safe, reclusive, neat little creatures. I've had them in my tanks for years with no problems. Second photo is a challenge. My first impression is that it looks like it might be a Cowry of some sort with its mantle pulled up and over the shell. Problem is, I can't quite tell if I'm seeing a hard surface/shell with protruding tube feet/sensory organs around the perimeter, or if the whole thing is soft, like some kind of slug. If you could get me a photo or two of the critter from another angle, fully submerged, that would be great. Also, what's the size? Does it feel hard (like there's a shell just under the surface), or is the whole thing soft? Where did the live rock originate? By the way, here's a photo of a juvenile Tiger Cowry (Cypraea tigris) as an example, so you can see how very different these animals can appear when the mantle is covering the shell: http://www.sydneyshellclub.net/icon/liveshellsNSW/Cypraea_tigris_Juvenile.jpg Without the mantle: http://www.gastropods.com/6/Shell_96.shtml The third and final photo is of an Ophiuroid/brittle star of some sort, also reef-safe and beneficial. For more information please see the following links (as well as those associated links at the top of each page: Pistol Shrimps: http://www.wetwebmedia.com/pistolshrimps.htm Cowries and other Gastropods: http://www.gastropods.com/6/Shell_96.shtml Brittle stars: http://www.wetwebmedia.com/brittlestars.htm Thanks, Steve <You're very welcome. Take care, LynnZ>

Re: Hitchhikers: Pistol Shrimp, Brittle Star, Possible Cowry -- Nope: Cuke 4/30/09 Hi again, <Hello Steve, thanks so much for the new photos. Those are exactly what I needed!> The little black critter is about an inch long, and it feels "sort of" soft to the touch. There were 4 of them on the Irian Jaya Live rock. <Good, that location fits right in with what I found. Your little critter is not Cowry at all. It appears to be a common Dendrochirote Holothuroid/sea cucumber, called Afrocucumis africana. These are shallow-water Cukes that apparently like to hang out underneath rocks during the day or within loose rubble, and supposedly only get up to about 5cm/2' in length. Please see the following links for more information and a nice selection of photos for comparison: http://www.poppe-images.com/images/image_info.php?picid=924831 http://www.poppe-images.com/images/search_results.php?category=Sea%20cucumbers&family=CUCUMARIIDAE For more information on Cukes of this sort, please see the FAQ titled 'Anemone Id? Nope, It's A Cuke! 8/10/07' at this link: http://www.wetwebmedia.com/cukeidfaqs.htm > I was thinking that the brittle star was the fish eating green brittle, so I was glad to hear that it is not!! <Indeed! Although it's difficult to see much detail in the original photo, the central disk of Ophiarachna incrassata (aka the green brittle star or 'green death') tends to be less star-shaped and a bit more round. See the photo at this link for comparison: http://www.poppe-images.com/images/image_info.php?picid=900461 and refer to WWM for care related issues re. > Thanks so much for your help! Steve <It was a pleasure, Steve. Take care, LynnZ>

Cucumber ID/Compatibility 12/18/08 Hi Crew, <Hello Carlos> It's been a while, my system is now 2.5 years old and absolutely cruising. Thanks for all your help these past two years. <You're welcome.> Well I wanted to add some new live rock to the system and replace some of the sand. What should I find in the live rock, but this little guy. At first I panicked thinking it was going to it's "puking thing" and wipe out my treasures.....but it let me take it out without harming anything. I have it in this isolation holder at the moment and will probably move it to my hospital tank for now. I have searched all the pictures and can't quite place the species. Any Ideas? Is this one the in-patients types or one that will be safe? Do you think it will be safe in my main system or should I take it to my local FS? He sure is cool looking, but I would rather not risk it if he is one of the bad types. <What you have appears to be a Holothuria species and are excellent detritus eaters. They are reasonably safe but if provoked often enough, they can release a toxin that can be harmful to fish. This could also happen when it dies. Do read here and related articles/FAQ's before making your decision to display in your reef tank. http://www.wetwebmedia.com/seacukes.htm> Thanks again. You're welcome. James (Salty Dog)> Cheers Carlos

Anemone Id? Nope, It's A Cuke! 8/10/07 Hello again Crew. <Hi Daniel> I was wondering if any of you could venture a guess as to what this is. <I'll sure try> It looks to me like it could be some sort of anemone, but I couldn't find anything that looked similar to it. When I first saw it, I thought it might be a basket star. (Because of the arms...) <The first time I saw one of these in my tank, I thought the same thing!> Looking at it more closely, it has a stalk or tube that the oral disk is on, so I am assuming it couldn't be a star. <You're right> I tried to get a picture of it both open and closed to help with the ID, but I couldn't get it to focus well when it was closed. <That's okay, I know how difficult it can be to get those pictures! In this case, the "Open Mouth" photo was a big help!> Here is what little I know about it: It is attached to a piece of live rock, it opens at night, and it seems to be feeding by inserting its arms into its oral cavity. (It almost looks like a child sucking its fingers clean.) <Apt description> It is about an inch across including the arms, and the oral disk is about a quarter inch in diameter. When putting its arm into its oral cavity, the mouth opens almost the entire diameter of the oral cavity. If there is any other information that might help you ID this, let me know and I will do my best to find out. (Or get a better picture) <Thanks, Daniel, I think we're okay with what you've sent. What you're seeing in the "Open Mouth" photo are the feeding tentacles of a Dendrochirote Holothuroid, or sea cucumber. Some "Cukes" lumber around on/burrow into the substrate, gathering/feeding the sediments into their mouths by means of short tentacles. Others are suspension/filter feeders and are generally stationary, many times living within a crevice. This is the type you have. They feed by means of extending their sticky/branched tentacles out into the water column, bringing any food back to the mouth - one tentacle at a time, in the manner you so aptly described! It does look a lot like the Cuke is licking its "fingers"! Keeping these guys alive can be a challenge, as they need lots of food to survive. However, if you've got a mature system, with enough nutrients, etc, in the water, it could last for quite a while. One thing with Holothuroids that's always a concern though, is the dreaded "Cuke nuke". When Holothuroids die, or are stressed, they can release a toxic substance into the water, sometimes with tragic results. Some species are worse than others regarding this, so it just depends on tank/Cuke size and what specie you have (and I'm sorry to say that I can't Id it to that level). However, it sounds like the one you have is fairly small, and hopefully stays that way. Unless you've got a very small tank, chances are good that you'd be okay. This is especially true if you know the Cuke's in trouble, and employ good skimming, water changes, and carbon use. I'd just keep an eye on it. Signs of decline would include the Cuke not extending its tentacles regularly, not capturing/returning food to its mouth very often (say about once/minute), and a slow shrinking of overall size. That last factor would be difficult to determine if the Cuke is hidden in the rock, so you'll most likely have to depend on the first two indicators. Personally, I think Cukes are fascinating little creatures, but unfortunately, they do come with some caveats. Please read through these links for more info re: http://www.wetwebmedia.com/seacukes.htm http://www.reefs.org/library/aquarium_net/0498/0498_3.html http://www.advancedaquarist.com/issues/jan2003/invert.htm> Thank you for your time. Daniel <You're most welcome! -Lynn> Re: Anemone Id? Nope, It's A Cuke! 8/10/07 <Hi Daniel> Thank you for your help. <You're very welcome, and thank you for writing us. I always love seeing what interesting critters show up in people's tanks!> I never would have thought to look through sea Cukes... <I know what you mean. If you've never seen one before, it's not exactly the first thing that comes to mind! I know the first time I saw one, it just about drove me nuts trying to figure out what it was. Anyway, I'm glad I was able to help. Take care and let us know if there's anything else we can do for you! -Lynn> Daniel

Sea Cucumber 5/31/07 Found this on the beach on Jekyll Island in Georgia, someone thought it may be a sea cucumber? <Bingo!> Thanks, Michele <You're very welcome! -Lynn>

Starfish Reproduced? Not this time - 08/15/06 Hey guys, Quick question for you. I have two green Bahama starfish in my 90gal tank. Tonight, it looked like one of the starfish everted its stomach, but after about 10 minutes, I looked back and it left a whole section of what I thought was its stomach on the glass and it moved on. The 'gunk' was sticking to the glass with some tube feet, so I thought it may have eaten one of my sandsifting starfish and it disagreed with him, but upon closer examination, the 'gunk' started to unravel and move about. I'm guessing it just reproduced, but right now it looks like a cucumber. I'm attaching pictures, so if you could confirm what I'm seeing, I'd appreciate it. Hope the pics are not too large. First pic is the starfish. Second pic is what it 'released' <Does appear to be an actual sea cucumber... might have been ingested... and egested (for sure!)... not palatable. Thanks for sending this account, pix along. Bob Fenner>

Re: Starfish Reproduced? - 08/15/06 Bob, Thank you for the quick reply. I do have one concern though. I did not have any sea cucumbers in my tank to start with. I avoided purchasing them for the potential of poisoning a tank upon stress/death. <Likely a "recruit"... most likely came in as part of live rock... perhaps live sand, or other hard substrate with other livestock> I'll keep researching I guess. It has very similar skin to the green Bahama starfish with greenish color and small spikes on the body. I don't have enough knowledge about reproduction, <Can be found in textbooks, the Net... looks to me to be a Holothuroid though...> so I can't say that is what happened though. If you'd like me to send you occasional updates, let me know. <Thank you, please do. Bob Fenner>

Sea Cucumber 2/9/06 I have had this cucumber for about two years now and am unable to locate an identification of it. It is doing fine and does a great job of keeping my sandbed as well as the rocks cleaned of all detritus, Am just wishing to call it something other than "that green one". I realize cucumber identification is very easily done, thanks for any help possible. This specimen was collected by myself here in the Philippines. <Charles, I've looked through whatever pics we have on our site and other sites and can't find a match. There are about 900 species of cucumbers and you may have to Google for a while to find it. We just don't have the time to do this. I do believe it is a member of the Holothuria genus, may help narrow your search parameters down. James (Salty Dog)> Charles Raabe

TWA Sea cucumber ID Hello <Hi there> I know that I definitely have several sea cucumbers, but haven't been able to locate the species. I live in the Bahamas and harvested them from a tidal area under some rocks. The cucumbers are a light grayish brown with little nodules al over the skin. They are quite active at night and during the day hide in the base of my live rock. I use a mixture of sands in my reef tank and them seem to rotate between digging in the sand and "surfing the live rock with their mouths. Can you please give me your best guess at to what species they are and whether or not they will be good for my tank long term. The seem to benefit as well when I feed invert smorgasbord from coral life. Regards, J. Andrew Thompson <Can't say off-hand by your description, but you might look on WWM re the group... and if it were me living and diving in the Bahamas I would definitely have a set of Paul Humann and Ned DeLoach's works on the identification of reef life there... Am sure their comb-bound guides include this Holothuroid. Bob Fenner>

Sponge? Greetings: Have searched your archives and forum, but haven't seen these, and I'd like to know if they're "bad" or "good". They resemble small (.5 to 1 cm) pineapples, but appear to be sponges. They prefer lower light in my 125 reef tank and my 44 FOWLR, judging by placement. I've attached a small photo. One or two reside on live rock, but most are on "reef bones" or other dead / ornamental rock. Bob's book discusses sponges that can harm other invertebrates, and I have various corals / anemones. Any worries? <Don't think so... do they move about? Looks like a small sea cucumber to me... oriented as it is on its apparent side... with processes/tentacles grouped on one end> Also, I have very small (1mm) hard, white objects on plumbing and glass. They're semi-circular, looking like miniscule gnocchi (sans alfredo or marinara sauce). Any concerns there? <Nope... these are very likely tubiculous tubeworms... large ones are often called Featherdusters...> Indispensable web site and archives! Have found answers to every question (few hundred or so!) since starting a year ago. Someone needs to collate your archives into a curriculum. <Yikes... you're frightening me...> My fish and invertebrates most sincerely THANK YOU for putting in all the hours answering these questions. Jon in da Nort'woods <Bob Fenner in strangely rainy Southern Cal.>

Re: Sponge? Re: question on mobility of sponge / sea cucumber: they are stationary; I can't detect any motion at all. <Strange, but not unheard of... there are Holothuroids/cucumbers that are immobile... filter feeders> I looked closely at live rock in my reef, and can see about 25 more of these organisms, some very small. All are in areas shaded from my lights. Tank is about 6 months old, with ammonia, nitrite, phosphate all at zero and nitrate near zero. Calcium a bit low (I think) at 260. Same w/ 44 FOWLR tank, which has about 10 of these interesting guys. Hope I'm not seeing an outbreak of something harmful. Tentacles / processes don't seem to retract (at least during the day). Live rock is supposedly from Fiji. Jon <Not harmful likely... could be siphoned out if they bother you... and could be something else... sponges even! Examination under a low-power microscope, use of a decent reference work will disclose the phylum... Bob Fenner>

Cuke Question Bob, Anthony, et. al., <howdy, my Texan friend> Just read your entire sea cucumber section a day after I was talked into buying a sea cucumber at my LFS. What did I learn?.....to ALWAYS thoroughly research everything before putting into your tank! <Ha!... rather ironic as you soon shall see> Especially when you have a 10-gallon Nano, like me. (Doh!) Other inhabitants are a Candy Cane, Green Star Polyps & assorted mushrooms (three are Ricordea). In short, this little guy's going back to the LFS tomorrow, but thought I'd see if you can ID him before he hits the road (pic attached). See you around, Ross, DFW/Texas <the Cuke you have purchased is Holothuria thomasi, AKA Tiger Tail cucumber. They are known to reach lengths of 4 to 6 feet! You might say that it would be too large for a 10 gallon aquarium. You made the right call :) Best regards, Anthony>

Re: Id please? Hi Crew! <Cheers!> I just purchased some more LR and this creature was a hitching a ride on it. I'm assuming it's a cucumber. <correct... a Holothuroid sea cucumber> Can you ID it? <not from this photo my friend. Have you seen it distend filter feeding appendages in to the water column to suggest that it could be a Cucumarid? Or instead bury them like a Holothurids?> Are these safe to be in a tank? <the later more than the former. Most all are fairly safe if protected from pump intakes like we do with anemones> From what little I've read in the past about Cukes is that one should be very careful/leery about housing one. <barely> Is that true? <overrated IMO> or they just stir the sand? <we need a better ID first> Thanks a million! Justaguy <best regards, Anthony>

What is this?!!!! Cucumber? >Hi Crew, >>Greetings Jocelyn. Marina here this morning. >My name is Jocelyn. I am taking care of my husband's saltwater reef tank for him while he is deployed. I was watching the tank one night with its lights off to see if I could spot any nocturnal behavior. I had my face inches from the glass when this "thing" slid out of an opening in the reef. It's shaped somewhat like a worm, smooth surface and "fleshy" like a worm. It appears to be a gray color with a lighter bottom-side. It also had a couple of small rings around it. Its "mouth" looks a lot like that of an elephant's trunk. I couldn't see any tentacles, fibers or teeth inside. Just looked like a smooth opening. It appears to have the ability to stretch way out in length and also swell to about a little smaller than the radius of a pencil. When I flicked on the light, it quickly shriveled in size and retracted into the reef. Its mouth looks like it's vacuuming the reef. It doesn't crawl or slither. It acts more like one end of it is attached to the reef and the mouth end stretches out to wherever it wants to feed. Any clue what this might be? We've had the tank for over a year and NEVER seen this before!!! I've been all over Google and can't find anything. Any help in this matter would be greatly appreciated. >>Well, it does sound something like what I've seen in Puerto Rico, the common name there for them is "Los Mojones" (means "The Turds" in Spanish), however, they are much less flexible in their activity. It could be a sea cucumber of some sort, is my guess. It is more than likely a detritus eater, and I would expect it to not be harmful at all to the system. If anyone else on the crew sees this, or another hobbyist who's seen it before, maybe we'll get lucky and they'll chime in. Best wishes to you and your husband, and safe return home (I'm sure you miss him like the dickens). Marina

What is this?!!!! Cucumber? >Thank you for your help Marina. >>Quite welcome, Jocelyn. >I can't wait to tell my husband there's a "Turd" in his aquarium. Ha ha ha. I'll continue to watch for it and Its activities. Thanks Again!! >>Oh my God! LOL!!! He should love that, and so should his company, eh? Maybe a streaming video would be in order? All my best, Jocelyn. Marina

Possible sea cucumber? I just returned from the Bahamas where I did a little snorkeling. I saw something on the ocean floor (actually I saw 2 of them) that looked like a gel-type snake. It was whitish or sand colored and coiled up like a snake might be. <No marine snakes in the tropical West Atlantic> It was at least as big around as my wrist and looked like it was 4 - 6 ft long. The person I was with got freaked out that it was a snake and wanted to go back to the boat so I didn't get a chance to watch it for long. On the way back I saw another one that was smaller, but also coiled up on the ocean floor. I asked the boat captain (yacht, not dive) if he had ever seen anything like that and he hadn't. I have snorkeled quite a few places and never seen anything like that and have been searching the internet today trying to determine what it was. Any ideas? Thank you, Mona Cabler <Very likely was/were sea cucumbers. Please see here: http://www.wetwebmedia.com/seacukes.htm Bob Fenner>
Re: Possible sea cucumber? Thank you for your prompt reply. I did look through the site before I sent the question and saw that there were sea cucumbers around the Bahamas. I did not find any pictures that looked like what I saw, but a sea cucumber seemed like the most likely answer I have found. They were long and bigger than I knew sea cucumbers got and of course, now I wish I would have stayed & watched for a while instead of accompanying the other person back to the boat. Any suggestions of books or websites that might have more pictures? <Paul Humann and Ned DeLoach's Guides are the best here. You can find them on Amazon et al. Bob Fenner> Thanks again, Mona Cabler

Found a strange "worm" thingy Hello! What is it??!! I've search a few of the FAQs and I can't seem to find the answer to my question... I don't want to say "it looks like a worm" because I don't know want to put the wrong picture in your head. (Since many people have different ideas as to what is a worm and what isn't). I'll try describing it. It's about a centimeter and a half long. It is brown on top with a dull yellowish underbelly, and one end is dull yellow. It's about half as thick as a pencil. And has small brown "knobs" on it that have a black dot on the tip. I've also seen a couple small, thin yellow arms on the side/bottom of it. I found something that looks like it here, kind of: http://library.thinkquest.org/J001418/seacuc.html But it doesn't have as many protrusions as that one... I can't tell which end is the head... Any help in the right direction would be great, thanks! Jason Thomas France >> <Hmm, well, it does sound like some sort of Sea Cucumber... and there are a bunch of types it might be... The important bit is that this animal is likely not deleterious... and so, unless it gets really big, or numerous... I would leave it be... and enjoy it! Bob Fenner>

Identification question I took the attached photograph in about 15 feet of water off the coast of Dominica. The area would best be described as boulders/large rocks. I was at the end of the roll of film, so I decided to take the shot with a 20 mm lens (as opposed to a close-up shot), co the definition could be better. Any help with an identification would be appreciated - even just a nudge in the right direction. <Hmm, looks like the end of a Donkey Dung Sea Cucumber... Holothuria thomasi... there's a couple of pix of this species on our site: http://WetWebMedia.Com/seacukes.htm Bob Fenner> Thanks Shaun

Critter ID I will try my best to describe it. First off, I have only seen it twice, both at night. It looks kind of like a huge snail, but has no shell. It is mostly flat and tear-drop shaped. About 1 inch to 2 inches long, maybe a little longer. It has antennae and little black dot eyes. It suctions up to the glass with its body and moves around quite quickly. It has a separate head and its little circular mouth sucks up to the glass and moves around like a vacuum cleaner very quickly. It is light-greenish brown in color. Like I said, it doesn't have a shell and is thin, but has kind of a curved back that looks to have darker sand or something on it - not sure. My concern is that it is pretty damn big and moves pretty quick. I would say it might be a snail without a shell, but I don't know, I have never seen one of those. Thanks for the help with the ID. <Mmm, curiouser... a separate head? Moves quickly... as in faster than "the average snail"? There are worm, mollusk groups that this stranger may be part of... rather than my fave guess group- sea Cukes. If it were up to me, I'd take some pix, show them about on the Net. Bob Fenner>

Loch Ness Monster in my tank! Hi Bob, <Hello> I'm new to reef keeping and have found your site invaluable. I've made mistakes from my own lack of knowledge but I've also run into problems with misinformation from my LFS. I've decided your book goes with me to the store so I can look up any new critter before I bring it home. <Hmm, wouldn't it be great (or shall I ask, when will it be so?) to have the Worldwide Web available at the shops? With "bookmarked" sites, sources of information, opinions... like bulletin boards, chatrooms, specialty sites... to render, offer such input?> We've had a 46 gal tank with no coral set up for a month. It has 50 lbs of cured Fiji LR + couple pieces of cured Tonga, 40lbs of LS, 20 lbs of crushed coral substrate. I'm using a HOT Red sea Berlin skimmer with a FB 300 Lifeguard Fluidized sand bed filter, a CPR 12" AquaFuge, for circulation 2 AquaClear 301's, and one ZooMed PowerSweep 226. The system is lit with 144 watts. of power compacts. The water conditions are ph 8.1 nitrite .1 nitrate 5 ammonia 0-.1 Phosphates 3 <Three? Hopefully 0.3 ppm... Three is too high... as you likely are aware> Tank is stocked with 4 peppermint shrimp 20 blue legged hermit crabs 1 sandsifting starfish 1. 2" mandarin (He is fat and happy-I take extra special care of feeding him after reading on your site!) 1. 3"-4" Midnight Tomato Clown-am taking him back to LFS-hides all the time and picks on other fish-lesson learned on purchasing too mature of a fish <You are correct> 1. 2 1/2" Yellow tailed damsel 1. Purple tipped bubble anemone-I read you don't prefer this but was told it would help clown-who's scared of it- and was supposed to be easy first anemone. 1. purple Nudibranch We purchased 2 pieces of what was supposed to be Cured Tonga LR. We have two identical, unidentifiable creatures. They're scary! The one we've battled with is approx. 6" long, 3/8 to1/2" in width. We thought it looked like a snail or slug but it's surface is hard. It has no apparent eyes or head or tail. It's grayish, tanish and has small nubs or spikes along its outside edge. It also has black elliptical patches that run down its back in the center. It's twisted around in the LR and it comes out of its hole at night. It is flat like but thick when it's out. It moves slowly almost like the Nudibranch. But when we tried to pull it out with plastic tweezers we discovered that its back is shell-like and hard. It is very strong. My 6'3 and 210 lb. fiancé©? couldn't pull it out or even squeeze it. The tweezers slipped off and left a small scratch on the casing. <Take care not to pull too hard, break this organism... more trouble than leaving it be... Likely some sort of sea cucumber... as its hardness points> Now, you ask, "Why haven't you moved the LR to remove the creature?" Our purple tipped anemone has just attached to the LR. So the questions are... What is it? Is it bad? Can we move the anemone and take LR out? How do we get creature once out of tank without killing everything on LR? <Perhaps try offering different foods toward night time... away from the live rock it's typically associated with... to lure it out for removal.> One more quick question for my reef life line. Are my skimmer, filter, and refugium too much weight hanging on the back of my tank? <Good question. Should be fine... the compression strength of glass, acrylic are tremendous.> Thank you so much for your website. We spend hours reading it. We've found your site informative and entertaining. Your regard for the ethics of the hobby are inspiring. Thank you for this much needed service. <Thank you for your kind words. Life to you. Bob Fenner> Barb and Justin. See attachment for sketch of creature. Tried to photograph and couldn't. Have never seen creature totally out of the LR. << lochness.PCX >> <What a crack-up! Still am sticking with my Holothuroid guess. Be chatting. Bob F>

Cucumber ID <Paul... Anthony Calfo in your service> Would it be possible to get a positive idea on this jpeg??? <unclear in popular aquarium literature but it does filter feed like Cucumaria sp> I know it is a cucumber but I would love to the specific taxonomic relationship if possible. There is so little known about the this "Cuke" yet available freely in the "reef" trade. Thanks for everything, Bob. <these filter feeding cucumbers are more difficult to keep in captivity than the detritivore feeders. If you didn't buy one yet... I'm inclined to suggest that you don't. Without unique plankton generating refugiums (aliotoms and bacteria from Seagrass refugiums and the like), I believe that you will have to work hard to help this filter feeder realize a long captive lifespan. Anthony>

Sea Cucumber Identification Hey we have emailed a few times. I live near Monterey. We talked about meeting up for a brew or two......or three...... J/K. Not really a drinker. Anyway, you have a picture on you WetWebMedia (two pink and green colored cucumbers together (appear to be at the top of the tank) Anyway, I was duped into buying one about three months ago now. He seems to be doing well. He grew quite a bit the first few months and now he seems to be slimming down a bit. Nothing too dramatic. <This happens> Quite a neat critter but since I value your opinion so highly, I will never buy one or recommend one again unless I get a grant for research. Anyhoo, I was wondering what the hell is this particular Cucumber. I have asked many all who have no idea other than....."Yep, that is a cucumber". or "Not sure what species of cucumber specifically, but I would get rid of it right away". I don't have any fish just 2 starfish and some snails and crabs. Corals and live rock are the order of the day. No special filters or protein skimmers. Basically, a 20 gallon refugium that I change water in almost every 2 weeks. Sometimes earlier. Anyway, Tank just keeps rolling along, but I can't find reference to this guy on any website other than the picture you display in your Cucumber FAQ!!!! I would love to get all the taxonomic specs on this guy. <This is almost certainly a Cucumaria sp., family Cucumariidae, Order Dendrochirota...> Anyway, off to Marine Biology class I go......Thanks for all your help in the past and the present. I will send pictures if you like. One 10 gallon tank I have had for about a year done the same "refugium style". I get lots of compliments on it. So I decided to try the 20 gallon. Working out pretty good. No skimmer or filter other than Caulerpa and live rock/sand. Haven't lost a coral yet!!!!!! (Probably shouldn't brag about that, I might have just doomed myself.....wait...knocking on wood) Anyway, water is steam distilled and salt is added and let to stand for 2 weeks!!!!!! Been working out great. By the by, my wife and I leave for Palau for our second trip in less than a years time to get some more macro diving in. We great luck last time and saw every creature they had to offer (practically). So I am looking forward to meeting Larry Sharron this time (although I have had trouble emailing him lately.) We have mutual friends in Palau and just didn't get a chance to meet up. Do you know him? <Ahh, strangely enough, just read an email forwarded from Larry (to the AMDA)... still out there after fourteen years. Bob Fenner> Take care, Paul Mansur

Orange Knobby Cuke Hi Bob, Quick question. Can you tell me the species name for the "Orange Knobby Cuke?" Looking for particulars on this Cuke but can't come up with the species name. Also, what is your opinion of using Cukes for clean up in a reef system? I'm extremely reluctant because I've read tons of frightening articles about them "eviscerating" and wiping out an entire tank of fish. Do you keep them? What's your call on this one? Tanks, Peggy <Please have a read here: http://www.WetWebMedia.com/seacukes.htm and the linked files beyond. Bob Fenner>

A weird slug- type thing in my aquarium. Hi, I recently got a beautiful 30 lb box of live rock from gulf-view.com .A couple of nights ago, we saw (what appeared to be a leg of a black, spiny starfish) coming out of a hole in one of the rocks. After a couple of minutes we got a better look at it and it was the size of a slug that you would find outside, but it was black with spots or raised spines, tentacles) that were a cream color on it. <they were cerata if it was a sea slug/shell-less snail> Well, after that he was nowhere to be found. Last night, we see a crevice in another rock with something odd in it also. It has purple tentacles that resemble the "tree" in a sea apple cucumber ( how it looks like there are little branches on it). It has about ten little tentacles that were arranged around a small black space, and it a weird pattern, it would pull one tentacle inside, and push another one out, constantly. It was really like nothing I have ever seen. <indeed... that most definitely was a sea cucumber> Today, I see that in the same space that it was in, now looks like a small tip of the slug-type thing I mentioned also. What could it be? Confused Kristie <a picture if possible...jpeg and sized smaller for web viewing. Else the description is too general to help you, alas>
Re: A weird slug- type thing in my aquarium. I apologize for being confusing, but the sea apple you described is coming from where the slug crawled into the hole. When it is not active, you can see the tip of the slugs head/tail. When it is active, it looks like a sea apple. <alas... without a photo at least, we are just guessing. I can tell you that "the tip of the head/tail" of the perceived slug could not possibly look like a sea apple. The tentacles of a sea cucumber/apple are feathery with "pinnules" and move independently like fingers into a mouth. The cerata of a slug simply move like wheat in the wind or look like tassels. These are wonderful mysteries and discoveries as an aquarist and great to share and learn about in a local aquarium society. If interested...look into the existence of a local club or start your own <wink>. All very exciting :)>
Re: A weird slug- type thing in my aquarium. The slug was actually what had the tentacles on it and was making all the movement, so was it still a cerata? it seems that the "tree" comes out of the tip of the "slug's" body. <no, my friend. Cerata are the tassels on the back of a sea slug. What you described as tentacles feeding a mouth (pulling into the center) was simply a sea cucumber (like a miniature sea apple). Kindly, Anthony>