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FAQs about Sea Urchins, Sand Dollar Identification 1

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Related FAQs: Urchins 1, Urchins 2 , Urchins 3,
Urchin ID 2, Urchin ID 3, Urchin ID 4, Urchin Behavior, Urchin Compatibility, Urchin Selection, Urchin System, Urchin Feeding, Urchin Disease, Urchin Reproduction,

Echinoderm? Heart Urchin! 4/5/08 Hi, <Hi Chris> I stumbled upon your website and know you're the ones to help me. <We'll sure try!> I teach art through science in the Florida panhandle. <Yay! What an excellent combination!> I found something strange on the beach and want to show it to my students. The only problem is... I'm not sure what "it" is. It has radial symmetry <Closer to bilateral, but it's still pretty irregular, even for an "irregular" urchin!> and looks like some kind of sand dollar or sea urchin. <You're absolutely right! It appears to be a "Spatangoid"/Heart Urchin, most likely in one of two families: Brissidae or Schizasteridae. I'm guessing that with those deep petals and groove, it's the latter of the two. Thanks to your excellent grouping of photos, I've narrowed the search down to several most likely genera. Reducing it further, would require close-up, detailed photos, but since you have the specimen in hand, it should go pretty quickly with the links listed below. The first thing you need to do is count the number of gonophores, or small holes, located in the apical disk (where all the petals meet). There will likely be either two or four present, and if four, two may be considerably smaller. If there are two, then look into these genera: Moira, Paraster, Hypselaster. All have species located around Florida and are in the family Schizasteridae. Of the three candidates, Moira looks very promising, because of the combination of deep petal grooves and more pointed base. If in fact, your urchin has four gonophores, then take a look at Meoma, and Brissopsis. These last two look similar to yours, and certainly Meoma ventricosa is a common species so it's worth checking out. Just take a look at the detail in the line drawings for similarities/differences in plate, petal, and fasciole arrangement. By the way, most photos/drawings are linked to a larger version. Anatomy: http://www.nhm.ac.uk/research-curation/projects/echinoid-directory/morphology/hearts/intro.html Fasciole arrangement: http://www.nhm.ac.uk/research-curation/projects/echinoid-directory/morphology/hearts/fasciole2.html Moira: http://www.nhm.ac.uk/research- curation/projects/echinoid-directory/taxa/taxon.jsp?id=468 Hypselaster: http://www.nhm.ac.uk/research- curation/projects/echinoid-directory/taxa/taxon.jsp?id=443 Paraster: http://www.nhm.ac.uk/research- curation/projects/echinoid-directory/taxa/taxon.jsp?id=455 Meoma: http://www.nhm.ac.uk/research- curation/projects/echinoid-directory/taxa/taxon.jsp?id=393 Brissopsis: http://www.nhm.ac.uk/research- curation/projects/echinoid-directory/taxa/taxon.jsp?id=373 Another good site for echinoids, in general:  http://www.echinoids.nl/ > About 2 weeks ago thousands of spiny purple sea urchins had washed ashore at our local beach. <Wow!> This weekend we took a boat out to an island near Panama City, along with the tests of the purple sea urchins we found this test. Everything I found that looks like it online comes from the Philippines. Please help. I don't want to tell my students the wrong thing. <I can sure understand that! I hope the above links help. Please let us know what if/when you're able to get an ID!> Thanks a bunch, Chris R. <You're very welcome! Take care, -Lynn>

Re: Echinoderm? Heart Urchin! 4/5/08 <Hi Chris!> Thanks a bunch for getting back to me so quickly. <You're very welcome! It was a pleasure.> After comparing my test to the pictures, I finally decided the one I found was a Hypselaster. How cool! <Very cool indeed! It's especially neat to find such an intact specimen!> You never know what you might find on the beach from day to day. <Very true, and the bonus is that even if you don't find anything, it's still a day at the beach. What's not to love!> Thanks again, Chris
<You're very welcome. Take care, -Lynn>

Is This An Urchin 2/22/08 Hi <Hi Timm> I wonder if you could help me by identifying this shell I found on a beach in Mauritius a few years back. I think its an urchin but it's got holes in odd places. I enclose some photos of it. <Looks to be a Sand Dollar, believe what you have is commonly called a Sea Gopher. James (Salty Dog)>
Mr. Timm Turner, Thrapston England.

Is an echinoid test... Irregularian... RMF.

Re: Urchin Hitchhiker: Pencil Urchin - 1/31/08 Hey Lynn, thanks for the quick reply. Your response was very helpful/reassuring. <You're very welcome. I'm glad I could help.> And . . . You were right--a check on the tank this morning before the lights came on revealed that the urchin was indeed roaming out of his safe haven. I found him attached to the back of my tank (presumably munching on some algae/coralline). I was able to take a picture of him, although it's not great because I was trying t balance a flashlight and manually focus and zoom my Nikon at the same time. <Heeeheee! What fun that must have been! I do appreciate your efforts though. Let's see if we can't figure out what you've got!> What's your best guess? <Hmmm, well I can certainly understand your thinking that this is either a Eucidaris tribuloides or a Heterocentrotus mammillatus. There are certain characteristics it shares with each. My best guess is that it's something in the genus Eucidaris, possibly E. metularia (an Indo-Pacific species). Take a look at this photo for comparison: http://www.botany.hawaii.edu/basch/uhnpscesu/htms/kalainvr/fish_pops/cidarid/urchin01.htm Your urchin has the same shape to the tapering spines and basic look to the body, with the obvious lines/lighter areas between the spines. In comparison, Heterocentrotus spp. bodies can have an almost shingled, or armored appearance. This is due to a covering of flat(ish) short spines. Now that we're pretty sure it's in the genus Eucidaris, I can tell you that these urchins are omnivores. I would offer it seaweed sheets/Nori as mentioned before, sinking pellets, and the occasional clam/mussel "on the half shell". The idea is that if you keep it well fed, it will hopefully leave your other livestock alone!> I have also attached a picture of my yet-to-be-identified tree coral that I mentioned in my previous mail. Any ID information on this coral would be much appreciated as well. <It looks like a Capnella sp./Kenya Tree Coral to me. Nice looking coral! Please see these links for comparison: http://www.wetwebmedia.com/nephtheids.htm See the photos within the first continuing query here: http://www.wetwebmedia.com/nephdisfaqs.htm > Andy
<Have a great weekend! Take care. -Lynn>

Urchin ID: Tripneustes gratilla - 1/30/08 <Hi there.> I bought this Urchin a few days ago and am unsure what its called. I was wondering if you guys know? <Yep, it's an urchin called Tripneustes gratilla, commonly called a Sea Egg, Hairy Pincushion, Collector, or Priest-Hat Urchin. These urchins are omnivores, grazing on algae and seagrasses as well as scavenging and even capturing/eating pods and small crustaceans. They adorn themselves with bits of algae, rubble, shell, etc. Color can vary, and size-wise, they get up to about 4"- 5". Hopefully you have a large tank as these urchins need a bit of maneuvering room. Not only because they have a tendency to knock things about and snag/poke at things, but because their sting is toxic to sea life. Speaking of toxic, this urchin has the potential to deliver a nasty sting, so don't handle it with bare hands. It's not actually the spines that get you, it's the pedicellariae (modified tube feet) that do the damage so be careful!> Thanks <You're very welcome. Take care. -Lynn>

Re: Urchin ID: Tripneustes gratilla - 1/30/08 <Hi there.> I have the urchin in a 25 gallon. <Unfortunately, this is much too small for long term care.> Will the sting kill my other tank inhabitants if it stings them? <A definite possibility.> Thanks>
<You're welcome and good luck! -Lynn>

Re: urchin ID - couldn't find it in the archives... Antoine and RMF input jartanyon wrote: Found this little guy and thought he might be poisonous...any ideas? Justin >IDs from pics are often difficult. If you have the time/interest... do check out some photography forums for advice, too, my friend. With a few good pointers you could greatly improve your image taking. Maybe we can help here: what kind of camera are you using? (and do get an off-camera cord for that flash to hold it from above, my friend... a huge help right there) <<Good advice>> The problem with the pic sent is that your subject comprises only a fraction of the frame (always get as close to your subject as possible for these types of shots, and in general). <<Ditto>> As for the focus... with stronger light (from above or above-angled) you could increase your shutter speed and likely get a sharper image. Better yet... please use a tripod. <<As well>> Without a clear pic, its hard to say what genus let alone species this might be. kindly, Anth-< <<Is likely a juvenile Eucidaris species... family Cidaridae, not venomous as the toxopneustids...
Bob Fenner>>

Urchins ID, sourcing of a Ca. native - 05/08/07 Dear Bob, I'm desperately looking for a source of Strongylocentrotus purpuratus in Europe. <Mmm, is found off the coast here...> I need them for my research and it looks like it's impossible to buy them, at least in Poland. People in U.S. don't want to send them because they saying that the animals will not survive the journey. Can you give me any hint where I can find those urchins? <Yes... Have the folks at Tropical Marine Centre in the UK contact ChrisB at Quality Marine in Los Angeles... he can arrange for these to be sent to England, where they can be easily changed out, re-packed... should make it no problem... This species is well-known and used in many biological studies...> And, if it isn't a big problem, - can you identify the sea urchins on the photos? I think the one on picture (C) looks like Toxopneustes pileolus, don't you think? <Yes> What about picture (D)? <Most likely an Echinothrix calamaris> Thanks - Gosia Cebrat
<Welcome. Bob Fenner>

Flatworm Infestation/Biological Controls III - 05/03/06 Hey, <<Hey!>> I will, maybe I'll try my hand at growing flatworms in my 12 gallon. Last question though. Why would a long spine urchin at a pet shop have some spines black, some ringed, and some fading white? <<Nothing unusual...have seen before. Lots of species of "long-spined" urchins, have a peruse here and you'll see: http://www.wetwebmedia.com/urchins.htm >> Brian <<Regards, EricR>>

Sea Urchin ID - 12/21/2005 Hi! <Hello Ivan.> I went to one of the 3 fish stores around here (Ottawa) and I saw what they are calling a "Turtle urchin". I can't find any info on this kind of urchin... It has the shape of half a sphere with no spines. Instead of that, there were "scales" all over the body. All around the base, there are some kind of round shaped "legs"... Color: dark, deep dark purple (almost black) I'm not planning to buy one because I really don't trust this store (Big Al's - actually, I never buy live stock here, only salt because it's cheaper) but I found it was a very interesting species. Your help is really appreciated! <Well, I'm not really sure here. Based on your description (aside from the "scales") I'd say try looking for images on Colobocentrotus altratus or perhaps the heart urchins, order Spantangoida.> Oh! I have another question concerning my Ocellaris clown. He is acting quite aggressively. When I'm feeding my tank, he is almost jumping out of the tank to bite my hand. The only other thing he is attacking is my Royal Gramma, but he's never as aggressive as he is against me. I even have to capture him every time I clean my tank or do water changes. I have an Open Brain coral and the clown is acting just like it was an anemone. Is it possible that he is trying to protect it?? <Sounds like it. When he attacks the Gramma, is it near his "buddy"?> Anyway! Again, thanks for the help and for the great site! And sorry for my bad English: I live on the French side of the Ottawa River! ;) <Well written, better than many I've seen on the American side of the Canadian border.> Ivan V. <Josh>

Urchin's everywhere, ID, selection 9/24/05 Kind crew, I added some live rock from Gulf View about two months ago, every night or so, when i had time to check, I've noticed some urchin hitch hikers usually one, maybe two. Last night I counted seven, not including two black ones that I saw a previous evening. <Testimony to the good quality, careful, expedient handling of this natural product> It looks sim to Echinometra mathaei from the WWM urchin page but it's from Florida, they range from one at 1/8 inch in dia, to one a little over a half inch. They come out at night to feed on the rock and I never spotted one in the day time. Trying to identify, but my big concern is quantity and to find out how big they might get. I might have a deal worked out with LFS to maybe trade up on some snails?? <Okay> Or would I be better off keeping the urchins? <Likely better to trade... too many will scour the tank too much, poke sessile invertebrates> The tanks a 75 gal and wondering about how many urchins should I limit myself to. Any help would be appreciated. Thanks, Dave <Likely are Echinometra lacunter, perhaps E. viridis... I'd stick with one, two. Bob Fenner>

Giant long spine urchins ? Hi Bob, While diving off the rocks in Caribbean I dived down beneath a plateau into deep blue. There to my amazement I saw Long spined urchins with bodies of the size of a soccer ball with 2-3ft. spines! What do you think, freaks of nature? Imagine the sushi these could make! Earl <Wow! Have never heard of such large echinoids... were you able to take any pix with something for size reference? Bob Fenner>

Re: Giant Long-spine Urchins? Hi Bob, As it happens I am spending some time in the Caribbean later this month but not in that island. In the meantime can I ask you for a learned opinion. How unique will sea urchins this size be, do you think it will be news worthy and to what degree? If you are positive (and I can stretch the budget !) I will be then be tempted to fly over and try to get some good photos. Cheers, Earl <Very newsworthy... and of scientific note. I had a friend in college who studied echinoid test morphology... He told me many things re relative shape, thickness, ultrastructure concerning life/habitat and these animals' exoskeletons... Along with issue of size versus aspects of shape, practical limitations exist for 'strategies' of animals/species in these issues as well... Bob Fenner>

Urchin ID (9/28/04) Hey. <Hello. Steve Allen with you tonight.> Your site and chatrooms are awesome, very helpful and informative. <Glad you like it I get a lot out of them myself and am honored to play a small part of it.> I have an urchin. It's black with an orange eye thing in the center. <Top or bottom. Not an eye, BTW. Urchins do not have eyes.><<Actually, they do. RMF>> Do you know what kind it is? <If it has long spines, the orange spot (if on the top) you mention sounds like the anus of Diadema setosum. Look for pix on WWM, elsewhere.> Is it poisonous and will it harm any kinds of corals or fish? <Many urchins have either venomous spines or venomous feet. The spines of Diadema are indeed very sharp and venomous. Fish steer clear of them, although can certainly be accidentally impaled in small quarters. If you get stuck, you will be quite sorry. Minimum is intense neurotoxic pain and worst case a serious infection.> I searched the site but I couldn't find any urchins with orange eyes, unless it's part of a generic species. <Again, not eyes,> Your reply will be much appreciated. Thanks in advance. <These creatures eat by scraping algae and stuff off of rocks, including coralline, which they can rid a smaller aquarium of. They are also known to knock precarious piles of live rock over with their spines. You may not really want a Diadema in your tank. A better choice might be Mespilia globulus, but beware of the downsides of all urchins. Hope this helps. Search WWM articles & FAQs for more.>

What urchin is this? 10/8/03 Dear Bob, <Anthony Calfo in his stead> I hope you are very fine, I received your excellent book Reef Invertebrates last week. Thank you so much for it, it is an aquarists best friend and destined to be a classic I am sure. <kind thanks for the strong endorsement... glad it serves you well> I popped over to my LFS to buy some new Fluorescent tubes and saw some urchins there. I am having a bit of an Hair Algae problem (phosphates are slightly high) so I figured lets get my self one of these critters and see what it does. <not a bad idea at all... some key urchin species are grossly under-rated in our trade/hobby for this purpose> So I picked one up, so far it has not touched any of the hair algae, but did have a soft spot for my purple coralline algae, the little that I had. Any way I am trying to identify this critter, I know its from Indonesia and it looks very much like a Mespilia globulus, but I cannot see any blue on it, it also has this habit of carrying a lot of macro algae on its back like a decorator urchin. Its round and has orange and black short spines with white tubular feet. I do not have a digital camera so I cannot send in a photo. Do you think this guy could seriously add to slide in water quality? <no harm at all... but do consider a Diadema species (long-spines) instead for algae control. They are incomparable> I have a Majestic Angel in this tank that I certainly would not like to get uncomfortable. The angel has been with me for a month (she was 2.5 inches when I got her, seems 1/2 inch larger now) She feeds well leaves the corrals alone and eats everything I give her. The tank is only 50 gal much too small for the Angel but its her temporary home, I will put her into a large aquarium at the end of this year. Kind Regards, Jorell <no worries... the urchin is likely harmless, and just not the most helpful species available. Small pacific Diadema species are commonly available... do consider. Anthony>

What urchin is this? II 10/8/03 Hi Anthony, Thanks very much for your prompt reply. I will take your advice, I just got your book out and found a Diadema on page 333. I have not seen these guys here in Hong Kong, I will look harder. <Ah, yes... no worries. Diadema setosum and D. savignyi are very common in the trade/hobby. You should easily be able to get these from an Indonesian supplier> I think I will get rid on the existing one as it is feeding on my coralline algae, it looks very pretty though, but I bought it for a reason that it does not fulfill. By the way, taking a look at it again the feet are half black with the ends white. Could this guy be poisonous (i.e. could it be a Tripneustes gratilla species?) <I cannot say from the text description, my friend> how I wish I had a camera..., <do browse the Internet until then for pics and a species ID> he's now all over the glass, the guy is black with orange spines, he has a few white spines but only around this mouth, his feet are black with white ends about a third of the length of the feet. Sorry to be bothering you. <no bother at all... shared admiration> I work from home and the tank is right besides me, cant resist. Hope you understand and sorry again. Regards, Jorell <kind regards, Anthony>

Purple Sea Urchin Hi! My LFS has a "purple sea urchin." How can I tell if it's the California type that won't survive in my unchilled system? <Good guest ion... I would first just ask them... likely they know, or the species name may have been listed on their invoice from the supplier (Strongylocentrotus purpuratus and S. sanfriscanus are coldwater Californians... Otherwise, as far as I'm aware there are no purplish tropical species (though some Diadema look very dark/purplish).> Also, I understand it likes Caulerpa (have a lot) but how does it interact with a Trachyphyllia or Yellow Tang. There is a warning in Mr. Fenner's book about the latter. Thanks, David A. Bidwell (Big fan) <No positive interaction... but possible troubles with urchins cruising into a Trachyphyllia coral. Bob Fenner>

Sea Urchins Or? 1/12/04 Greetings Most Informative Wet Web Crew, <Greetings Flo!> I've asked you a couple of questions the 2 years I've been in the hobby and gotten some excellent advice mostly through reading the information on the site and books you recommend- so thanks and kudos to all of you. <Glad to hear you have benefited, and I hope to build on that tradition.> I have a question about some critters in my 40 gallon tank. I have no fish in there, just many small feather dusters, a few hermit crabs, and 1 snail. The tank has an overflow, sump, and skimmer. I feed the tank once per day just a bit of marine flake food. Because there is nothing in it, I haven't scrubbed the algae off the acrylic tank for weeks and it has only a hard green algae on the sides. I do change 5 gallons of water every week or so. <Wow! Such patience. I am already thinking ahead that you must have an amazing variety of critters enjoying a predator free environment!> In addition to this, there are about a million- maybe an exaggeration (probably more like hundreds or thousands) of little white colored things in my tank. They seem to be all over the acrylic and the live rock. I may have put some new live rock in the tank about 3-4 months ago and if I did it would have been a small piece (can't remember as I was prepping my new 100 gallon and mixed around some things). I have about 45 lbs of live rock that has been in the tank over a year. They are not brittle stars, I believe, as brittle stars have a central disk with arms coming out just on the sides. They are not copepods as copepods can move quickly and look like little bugs. They have a round central part that is about the size of a pinhead. They are all approximately the same size. They seem to congregate on the areas where there is green algae stuck on the acrylic and rocks. They have for lack of a better word "arms" looking like small thin straight but still mildly flexible threads coming out of their sides, top, and back, but not on the bottom which is the part stuck on the rock or acrylic. They are too small to see much detail, but do not swim, and seem to move so slowly it is hard to tell they move from one place to another. <There are a range of possibilities, but I would lean toward some kind of Foraminiferan.> As I have virtually nothing in the tank, I'll see what they turn into. I was going to stock the tank, but now will wait. I am curious as to what they could be, how big they could get, how to care for them, and what to feed them. I've tried looking for pictures or descriptions that sound like them, and the closest thing I see are sea urchins. <Baby sea urchins are a possibility. You could have imported some spawn material (Our own Anthony Calfo imported Cassiopeia larvae into his greenhouse). I too would be curious what they will grow out into, so please do let us know!> They resemble small white sea urchins. Is this possible? I want to get a picture but they are so small it doesn't provide a good representation of them and the algae on the tank makes it hard to get a picture. Thanks, Flo <Sorry not to have a better idea of what you have. Please don't be too surprised or disappointed if they just start disappearing. Many tiny critters wax and wane and come and go in our systems. Best regards and enjoy to amazing diversity of life that we have the benefit of keeping in our tanks! Adam>

Book: Sea Urchins of Australia and the Indo-Pacific It's finally available! Sea urchins of Australia and the Indo-Pacific Ashley Miskelly December 2002 180p. soft cover full colour throughout ISBN 0 9577455 6 7 The first full colour book ever published on Sea Urchins of Australia and the Indo-Pacific, this book describes and illustrates 85 of a known 220 species that occur throughout Australia and its offshore territories. Most of the species likely to be found from low tide to about 20m deep are included. Discover the variety of sea urchins that inhabit Australia and the Indo-Pacific as each sea urchin is described in a format that is not over-scientific nor too simple. Beachcombers, naturalists, divers, professional and amateur marine enthusiasts will all find this book useful. Each species is described in detail and illustrated with a number of colour photographs, showing, in most cases, the live urchin, and four different views of the test If you have previously ordered a copy, you do not need to do so again regards Patty **************************************************************************** ********** Worldwide postage A$10 per order! Bookshop: http://www.booksofnature.com **************************************************************************** **************** This is a once-only mailing to people dealing with the study of sea urchins. I am sorry to have disturbed you if you do not appreciate this information Dr. Patty Jansen Bookshop: http://www.booksofnature.com Publishing and info site: http://www.capricornica.com Books of Nature P.O. Box 345 Lindfield NSW 2070 Australia phone/fax: 02 9415 8098 international: +61 2 9415 8098 E-mail: capric@capricornica.com or books@booksofnature.com <Thank you for this notice. Will post on our root web. Bob Fenner, WetWebMedia.com>

Urchin We have an urchin that has seemed to have come with the live rock that we bought. It has been about 1 1/2 years since we purchased the rock, so it has been a while. I cannot seem to tell from the pictures on your site what types of urchin it is. It is a black urchin, the "needles" on it are long and skinny, and the very end of the tips are white. Is this a white tip urchin, and is it poisonous? Thanks so much! < Sounds like a long spine urchin (diadema antillarum) to me, and yes he is poisonous. Cody>

Urchin id Mr. Fenner, Just would like to give the feed back on this pick. I did as you requested and had the LFS request a scientific name from the wholesaler. After a week of waiting they sent me the name. " Asthenosoma varium" a otherwise called
<I do think this is an Asthenosoma species. Please see here http://www.wetwebmedia.com/urchins.htm> Fire Urchin. I plan to search the species more on WWM to see if they are considered reef safe. I have already placed mine in my 160 gal reef and have seen no signs of him eating or otherwise bothering the corals. Thank you for the advice David
<Watch your hands around this specimen. Bob Fenner>

Urchin ID Hi WWM, I was just hoping someone there could help me with the ID on this sea urchin. It was labeled a rainbow sea urchin at the LFS. I didn't think I would have any trouble finding out more about it. This is one of the few items I couldn't find on your site, Then I couldn't find it on any site. If you know what species it is could you give me a better knowledge of care, That is if it's different from all other sea urchins. Thanking you in advance, David P.S. Love the site, I'm another daily reader. <Mmm, don't know this common name. Have you checked through the few species and pix we have posted on WWM?: http://www.wetwebmedia.com/urchins.htm Maybe your dealer has an invoice for this animal listing its scientific name. Bob Fenner>

Echinothrix calamaris- Venomous purple urchin (pic attached) What type of urchin is this. <Echinothrix calamaris> I recently bought it from my LFS and they said it was a short spine white tip. <OK... many common names <G>> Can you tell me its scientific name and common name and any other info that would be useful to me. Venomous? <it is indeed venomous/toxic to people. The spines are hollow and open at the tip. This species is an indiscriminate feeder on green and meaty matter. Actually fairly well-behaved in reef tanks but not recommended by me for casual aquarium use> Thanks Terry Rickman
<best regards, Anthony>

Urchin ID - Toxic species 7/21/03 Dear Crew: <cheers> Please see attached photo. I bought this urchin at my LFS. I am uncertain as to it's ID. I believe it is a Tripneustes gratilla. <correct> I had read that it's OK for aquariums and read suggestions for how to care for it. <hmmm... OK as in won't eat reef invertebrates/corals - yes. likely true. But they are toxic to sea life/animals/you. Caution handling> I've also learned that it is venomous. <yep... the whole family is> Both I and the LPS guy have handled id bare-handed without consequence. <its not going to kill you... but geez! Do exercise caution/discretion here. Just because you didn't get stung the first time does not mean you won't the next.> Is this really T. gratilla, <as best I can tell from the picture, yes> or is it something else? Thanks, Steve. <my opinion is to avoid all such animals for casual aquarium keeping. Species tanks only if you must. Best regards, Anthony>

Toxic Urchin ID 7/22/03 Anthony: Thanks. I have attached a PDF file for your review. It is a source of confusion for me. It is the pages of Fossa & Nilsen's 4th volume of The Modern Coral Reef Aquarium that deals with this particular urchin (Tripneustes gratilla). Notice the picture of bare-handed handling. (I will use gloves if I ever touch it again.) Also, the text describes it as "a rather hardy and quite suitable urchin" that is 'frequently available in the aquarium trade." It also states that "a sting can cause severe pain in humans, but it is generally not dangerous." <all true and agreed... although the bare handling in the image, by the LFS, etc simply lacks common sense> Sounds a lot like a Rabbitfish or a lionfish sting. <hmmm... perhaps, although I would not fondle the latter two bare-handed either <G>> Still, I will not handle it again without protection. It is attractive and interesting. I would imagine that most fish will steer clear of it. Steve Allen <thanks for sharing... best regards, Anthony>

Filaments from Long Spined urchin 8/5/03 Hi guys <Howdy!> I just finished reading your "Reef Invertebrates" book - excellent! <Danke... tell a friend! That is to say, tell a friend that you liked the book. Not tell a friend "Danke"... although you could if you like. Or tell me and I'll tell them "danke"... er, never mind> I have a long spined urchin I was checking out the other night just because he's a freaky kind of guy when I noticed very fine long filaments coming from it's spines. They would retract in and out over and over. What's up with that!? Mark Seibel <I'm assuming the filaments you are referring to are not the modified tube-feet originating from the test (body itself) but rather literally from the spines (as is perpendicular). If so... they may very well be worms that are all-too common commensals with such echinoderms. Do share a photo of them if you can! Kind regards, Anthony>

Re: Filaments from Long Spined urchin 8/7/03 Thanks for the reply. I have attached a picture (not the best, darn digital cameras are hard to set the focus) and it does indeed look like there is something on the urchin's spine. Is this something to be concerned about? <nothing can be seen clearly in the pic. I'm wondering if you look at them with a magnifying glass what you will see? Look like worms? Or just slough caught from the drift? Anthony>

Astropyga radiata Dear Bob Fenner: I am writing to you about the urchin Astropyga radiata. <Okay> We run a dive charter boat in Morehead City, NC. Yesterday I collected an urchin at 130' deep, 40 miles offshore and I now believe it is an Astropyga radiata. No one we know has ever seen this particular urchin around here before. At this particular wreck site there were 4-5 colonies of 10-15 urchins each. Huge groups of these large urchins. <Neat> We gave the specimen to Paula Whitfield with NOAA, but at first glance her colleagues don't seem to think it is unusual for these waters. (She is also still looking for a more positive ID). Our first guess was Astropyga magnifica: based on the book "Reef Creature Identification" by Paul Humann. However, the photo does not match, and the description of the adult is inconclusive. The Audubon Field Guide North American Sea Creatures does not have anything resembling this urchin in it. <Don't know much re this echinoid... other than Humann's id you list> However, after an Internet search which turned up your photo and description...my suspicion is that it is a Pacific urchin (radiata), and may have arrived here the same way the Lionfish got here 3 years ago. (We have Lionfish inhabiting our reefs and wrecks now). <So I'm given to understand (groan!). Would be unlikely that someone would buy, dispose of two or more individuals of the Pacific congener... but a possibility> Can you positively ID the urchin you labeled as radiata in the photo here: http://www.saltcorner.com/sections/zoo/inverts/echinoderms/urchins/Aradiata.htm and here: http://www.wetwebmedia.com/urchins.htm (Some other websites have the Astropyga radiata and magnifica photos interchanged, and I would like an absolute positive ID on the red-colored urchin from your photo). <Unfortunately the saltwater corner site doesn't load> I would appreciate any assistance you can give me. Attached are 2 photos of the urchin I collected yesterday. Thank you very much for your time. -Renate, for Atlantis Charters <... and can't locate your attachments. Please do re-send. Bob Fenner, just back from Indo... where of all things, spent an inordinate amount of time searching an urchin (Asthenosoma varium) at similar depths to make pix of a commensal shrimp (Coleman's) w/o success>

Re: Astropyga radiata Dear Bob Fenner, Thanks for your response. In the meantime the urchin has been sent to the Smithsonian for positive identification. Should it turn out that it is another invasive species, you will surely hear about it. <Thank you. I appreciate the effort> I have uploaded photos of the collected specimen on our website: www.atlantischarters.net <I see it/them... do look like Astropyga radiata... sigh> Hope you have better luck searching your next urchin...!!! -Renate <Thank you. Me too! Bob Fenner>

Sea Urchins Dear Sir, I am a graduate student working on the taxonomy of sea urchins in my locality. I have been looking for materials written about Philippine Sea Urchins but I have been unfortunate in finding them. On this regard, I am seeking for your help in terms of sharing me some of your literatures on sea urchins or a guide for me on where to obtain them. Sincerely yours, Geraldine Andas, Libron <You need to develop a search strategy (for scientific literature on the topic)... and visit a library (or computer hook-up) that can get you to Biological Abstracts, The Zoological Record... Please see here re literature searches: http://www.wetwebmedia.com/litsrchart.htm Bob Fenner>

Species and Group Hello Sir Fenner! <Hello> Among the sea urchins I have collected are pencil urchins. I need to validate as to whether they are Eucidaris tribuloides or Eucidaris metularia or Heterocentrotus mammillatus. Another regular sea urchin that I have collected appears to be Tripneustes gratilla or Lytechinus variegatus but I don't have enough literature on such species. All of which have been gathered in my locality, Davao City, Philippines. <As far as I know, all of these are to be found in Philippine waters. What little we have content and reference-wise on urchins is posted here: http://www.wetwebmedia.com/urchins.htm Perhaps a literature search: http://www.wetwebmedia.com/litsrchart.htm is in order. There are likely survey works on the echinoids that cover the area. Bob Fenner> Geraldine

Update I know that it might be in the least of your concerns but I would just want to update you on the development of my research. I have successfully identified the specimens that I have collected. I am going back to the sampling site to gather more specimens (with bigger and better containers this time). Thanks for your help. Our written report will be due this October. Wish me luck! Geraldine Andas-Libron <I do wish you luck. Very exciting. Bob Fenner>

Urchin hey guys, sent you an email previously but never got a response, so I thought I'd try again. looking for some info on Echinometra viridis (reef urchin). I think this is what I have. it's brownish-purple with white rings around the base of spines (see attached jpg). <None attached> the guys at the LFS said it would be a good addition to my cleanup crew. so I bought it (yeah I know I should read up on these things first). I read all your urchin FAQs but have not found anything about this species, except that they eat algae. Am I correct in thinking that these guys eat ALL algae (micro, macro and coralline)? <Likely so> Aside from knocking things over, do you think this guy is going to cause me problems? <Probably not> Is there anything else that I should know about this species? <Not that I'm aware. This is a (relatively) sturdy tropical West Atlantic echinoid... well-suited to most types of reef aquariums> As I'm still trying to figure out what to put in this tank is there anything I shouldn't house with this guy? <Soft animals that might get poked... Bob Fenner> Thanks! your site is great!
Re: urchin thanks for getting back to me. guess I forgot to attach the picture. here it is. this is Echinometra viridis correct? <Does look like it to me> thanks again.
<Be chatting, Bob Fenner>

Unidentified Urchin Hi, Bob: I recently couldn't pass up a beautiful "blue-dot pin cushion urchin" from my LFS. He is about 4" in diameter with blue dots which fluoresce. I was told the critter is venomous. I was wondering whether you've ever heard of such a creature, and if you could tell me, though I don't plan on touching him, just how venomous it is (i.e., death, pain, etc.) Thanks for your ever-helpful advice. Marilyn >> Yes, there are many such colored species of sea urchins... and yes, they are venomous through their tube feet... but not very dangerous to you. Far more of concern are physical injuries from their sharp spines. Take care if you have to move one of these biological pincushions to utilize a net... and not lift it into the air (in other words, scoot the urchin into a container underwater... Bob Fenner

My new red sea urchin Hello Mr. Fenner: I am a beginner aquarist who has recently setup a 55 gallon tank. The biological filter is established and the water quality is excellent by all of my tests (NH3, NO2, NO3, specific gravity, pH and water hardness). I am inquiring about a recent addition to my tank. I currently have 3 Firefish, 1 blue damsel, and my new red sea urchin. I was told by the aquarium supplier that it is a red pencil sea urchin that would assist in reducing my tank algae, but it doesn't look like any of the pictures that I've seen. It is a mottled red-purple-tan color, with short, dulled spines. There is a picture of what it most closely resembles at www.coolmoose.org/fish.htm. <Yeah... I make this almost assuredly out as a Eucidaris metularia... and yes, it does eat attached algae... but wouldn't have expressly sold/suggested this as a/the algae eater for this system...> Anyway, my question is, it seems to have these white, squiggly looking attachments partially covering its spines. These attachments are open at one end, circular with fanned out filaments that crown the open end. Is this some sort of parasite, or is part of the actual sea urchin? If it is a parasite, how would I treat it? <Wow, you've got good vision! This is part of the Urchin, no worries> If I can provide any other information, please do not hesitate to ask. I'm going to look for a good encyclopedia of marine fishes, invertebrates, echinoderms, etc., to assist me with my questions. I just haven't found a good one yet. Thank you in advance for your assistance. <There are a few... not just one... (It would be a real bicep builder!)... Do check on the listservs, the www.WetWebMedia.com site's Links pages for input for reference works... If you have the funds, Scott Michaels "Reef Fishes" books are very nice, The Modern Coral Reef Aquarium for their first three volumes in English (a fish one is on the horizon) for invertebrates in captivity, and the Baensch Marine Atlases in three volumes as well... have all of these (and a few others) within arms reach. Bob Fenner> Deborah H. Colella

Sea Urchin Good Evening, <And to you> Two quick questions .... 1. I believe I have a small Sea Urchin in my 90 gallon, 2 month old tank. It came with the cultured live rock, it is as large as the end of your small finger, black, and has spikes sticking out all over. Hides all day and comes out at night. Seems to be growing quite a bit. Is this an OK resident? Can't seem to find much info on these things on the net. <Likely fine. Please see: http://www.wetwebmedia.com/urchins.htm Something like the Diadema shown?> 2. How do you feel about Activated Carbon, and how often should I change it? As usual I hear pros and cons. I have a TidePool Bio wheel sump system, with one tray of AC. Thanks for your excellent resources. <Please read here: http://www.wetwebmedia.com/carbonfaqs.htm You are welcome my friend. Bob Fenner> John Kummer

Sea Urchins Mr. Fenner, I came across your website, and was pleased to find a site that could answer many of my questions on sea urchins. I am researching the species, Astropyga magnifica, for a project I am putting together and I am having difficulty finding the complete classification, from kingdom to species. I was wondering if perhaps you knew of a source where I might be able to find this, and other information on this specific species, or if there was anything you, yourself, could tell me. Any help that you could give me would be very much appreciated. C. K. Spengler <Mmm... let's see o ECHINOIDEA (merisiilit) |--o PERISCHOECHINOIDEA | `--o CIDAROIDA | |-- Cidaridae* | `-- Psychocidaridae* `--+--o EUECHINOIDEA ()? [paraphyletic?] | |--o DIADEMATACEA | | |--o ECHINOTHURIOIDA | | | `-- Echinothuridae* | | |--o DIADEMATOIDA | | | |-- Diadematidae | | | |-- Lissodiadematidae | | | |-- Micropygidae | | | `-- Aspidodiadematidae Genus Astropyga is a part of the Family Diadematidae... Bob Fenner>

Sea urchin question Hello all! I have a question about this urchin that my LFS said ate just sea veggies. I've attached a photo. Could it possibly be eating my feather dusters? I have seen it on top of them and then the duster shed it's plume, and I've also seen an empty tube after the urchin had been there. I've had the urchin for about 3 months. I was told it was a pincushion urchin. true? Thanks for your wealth of info!! Stephanie <Whoa! This may be an Asthenosoma spp. or possibly a more innocuous Tripneustes spp... take great care, as this animal may well be toxic/venomous to you! Do enter both genera in your search engines and try to identify this specimen. If it is of the former genus it IS an indiscriminate omnivore, it may well have eaten your other sedentary invertebrates. Bob Fenner, who encourages all to investigate livestock purchases before buying!>
Re: sea urchin question Bob, I have identified it as Asthenosoma spp which is a "fire" urchin. Ahhhhhhhhh!!!! <Yeeikes! I thought as much... be careful. I photographed a gorgeous one a couple weeks back in the Red Sea... and took great pains to avoid... great pains!> I really appreciate your help in identifying. He must've had my dusters for lunch. Stephanie
<Keep your hands clear of it to be safe. Bob Fenner>

LR-Hitchhiking Urchins & Other Issues(3/8/04) I was checking out my new live rock after dark last night and saw what appears to be a sea urchin. It was about the size of a small button, black and had dull spines running along the edges, but not all around like most sea urchins I am familiar with. It also had several long, thin black wispy tentacles coming off it and waving around. I searched this site as well as the internet and the closest picture to match I could find was of a Shield urchin, but the photo was not very clear. 1. Does it sound like a shield urchin to you, where can I find a photo, and if it is, could it be a problem for my tank. <Well, urchins don't have tentacles, so I have to wonder. Does sound like one. Likely not something harmful anyway. At this point, I'd leave it be. Watching these LR hitchhikers turn up is half the fun. Next time I set up a tank, I'm just going to leave only the LR in it for several months to see what happens. As for pix, all I can recommend is to search the internet for the term. Check out www.wetwebfotos.com too.> I have a 55 gallon, FOWLR , protein skimmer, 2 powerheads and an emperor 400 and right now all I have is a Ocellaris clown, 3 Chromis and a "scooter Blenny" which is as I now know a Starlet or starry dragonet and I am trying to keep alive as I was misled into thinking it would eat algae. I have a large copepod population and a refugium tank with more copepods thriving so hopefully the dragonet will stay as healthy as he is now. He seems to be eating very well right now. <Good. Hopefully, this Scooter Dragonet will be fine. I believe that they are less difficult than Mandarin or Psychedelic Dragonets. Their smaller size means they don't need quite as much food.> 2. What are the dragonet's chances if I keep up the pod population? <Quite good I'd say. Mine has been thriving and growing for several months now.> I live in Charleston, S.C. and have access to as many pods as I can find at the beach. <A self-sustaining population is best because you risk introducing pathogens when you add stuff form the beach.> I started a 15 gallon tub of circulated saltwater loaded with sand and shells and pods as well in my garage and hope to be able to sustain a pod population there as well and transfer them to the smaller refugium as needed. <Do take a look at one of the smaller CPR AquaFuge HOT refugiums. A wonderful product. You might have to give up the Emperor to fit it.> Will this work, keeping in mind parasites, water conditions, etc.? I also have access to live food through the LFS. I know the chances of the dragonet's survival are slim to none, but is it mainly due to the food issues? <Yes, and I'd say it's not that bleak, especially if you can keep up the pod population.> I don't want to bring him back to the LFS as they were the ones to mislead about him in the first place and they might just turn around and sell him to some other unsuspecting victim ( though the real victim here is the dragonet) <Yes>, and I don't know anyone local with a reef system to give him to. I usually research my buys first, but was unfamiliar with the dragonet and was told it was a blenny <an unfortunately common error that educated dealers should stop making> which I was planning to buy anyways. The new sales guy at the LFS did seem a little eager to sell the "blenny". I learned a valuable lesson on researching before I buy and won't fall for that one again. <Good> I plan on doing everything in my power to keep the dragonet alive and fat, but is what I am doing enough? <Yes, consider the refugium> what about variety in his diet? <Your LR should sustain a sufficient variety.> 3. One more question: I bought my clown ( Nemo- very original name!) about 3 days ago and he adapted well, no signs of stress, etc. He was tank-raised so he seemed like a hardy choice. The problem is he literally spends his entire time swimming against the current created by my maxi-jet 900 powerhead. Is this normal? <This is common in clowns. If no other concerns, should be OK.> He isn't eating well either. <Give him a few days to adjust.> will take some dried plankton, but not much, if any, as he seems to spit most of it out. he won't take frozen or other dried flakes <Try frozen Mysis. Also, he may take good quality pellets.> that I can see and he doesn't seem to be scavenging either. What's wrong? <Probably just adjusting to the new tank, but you should have quarantined him. I'm a little concerned that the quality of clowns seems to be going down, probably from over breeding due to the Nemo craze.> The water is fine for the standard ammonia, nitrites and nitrates, etc. <We always prefer real number--some are less fine than others.> and the fish seem healthy with no signs of injury or stress so I am at a loss to the Nemo's problem. <Give it some time. Research on WWM for the signs/symptoms of Brooklynella, marine velvet & ich.> Sorry for all the questions, and even though I have quite a few years in the hobby, you guys are the experts and I defer to your wisdom. <Well, some are more expert than others, but all have experience, learning and passion.> Thanks for all the help and many enjoyable and informative hours of reading your website. <You're welcome. Hope this helps.> Jean

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