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FAQs on the Hydrozoan Identification 3

Related Articles: Hydrozoans, Cnidarians, Fire Corals, Stylasterines, Hydrozoan Jellies,

Related FAQs: Hydrozoan ID 1, Hydrozoan ID 2, Hydrozoan ID 4, Hydrozoan ID 5, Hydrozoan ID 6, Hydrozoan ID 7, Hydrozoan ID 8, & Hydrozoans 1, Hydrozoans 2, Hydrozoan Behavior, Hydrozoan Compatibility, Hydrozoan Selection, Hydrozoan Systems, Hydrozoan Feeding, Hydrozoan Disease, Hydrozoan Reproduction, Medusoids/Jellies (Ctenophores, some Hydrozoans, Scyphozoans): Jelly Identification, Jelly Behavior, Jelly Compatibility, Jelly Selection, Jelly Systems, Jelly Feeding, Jelly Disease, Jelly Reproduction, Fire Corals Lace Corals, Stinging-celled Animals

Tiny 9-point critter... Hydroid Jellyfish (Staurocladia oahuensis) 11/9/07 Hello WWM, <Hi Jesse, Mich here.> I have a picture of an interesting critter that is eating copepods. At least I think they are copepods. You can see them in the picture being eaten. Maybe it's common but I'm still new so could you tell me what it is <It is a Hydroid Jellyfish (Staurocladia oahuensis) More here: http://www.wetwebmedia.com/jellyidfaqs.htm http://www.ronshimek.com/Animal%20Groups%203%20Cnidarians.htm > and will it eat much of the fishes' copepods? <No.> We just noticed them and there are about 5 we could find quick and easy. <Their populations tend to wax and wane.> They do seem to move when they feel like it. <Yes.>
<Welcome! Mich>

Unknown hydroid hitch hikers. 10/25/07 YupHello Mr. Fenner, et al. <Hi Nate, I guess you would have et al with you tonight.> I set up my 75g tank about 2 months ago and my live rock was very much alive! <Great!> I bought it fully cured locally from a good source. I have seen snails, protopalys, feather dusters and lots of varied sponges. Along with the good stuff, I have received some not so good stuff. I have killed a few Aiptasia (w/ lemon juice), and stinging hydroids(with fire) but now I have a few other questionable organisms growing. First, I have these weird hydroid looking polyps growing on top of my LR. they look different than anything I have seen on your site, or any other site. They look like mini brownish white daisies (pics attached). Are these harmless or bad? and if they are bad, how should I go about removing them? <They do look like hydroids as far as I can tell by the pictures. More pic here: http://www.wetwebmedia.com/hyzoanidfaq.htm > Also, I am starting to notice more and more little digitate hydroids in my tank. none seem to be in close proximity to anything important, but I am starting to fear that I have another battle to fight. <I would not let these get too far out of control.> Any thoughts? <Manual removal with gloves being an absolute necessity!>  I skim pretty heavy and my parameters are all 0 for ammonia, nitrite, nitrate, phosph; dKH~ 10; calc = 480. <A little high.> I am having large growths of pineapple sponges, protopalys and feather dusters if that is important. <Just means there are nutrients in you water that are feeding these critters.> Keep up the good work, <Will try! Mich> Nate

Re: Unknown Hydroid Hitchhikers... Yup  10/26/07 <Hi Nate, Mich with you again.> Should I try to remove the hydroids on my rock? <I would.> You never said if they were bad for the tank or not. <They can be problematic, stinging other nearby life... why I said I wouldn't let them get out of control.> I know some hydroids can take over a tank like Aiptasia, but these don't look like those type. <Perhaps not, but can pack a powerful sting... If it was me I would remove, while wearing gloves! Mich>

Creature Identity... Jellyfish?   10/25/07 Hello! <Hi Renee, Mich with you tonight.>I hope today finds you healthy and happy. <Yes, thank you and I hope it finds you the same!>I am back with another interesting question. <Good I like interesting questions... so much better than uninteresting questions Heehee!> I cannot seem to find this identity anywhere online and hope you can assist me. <Will try!> In my refugium, I have some apple algae <Mmm apple algae? I do see some grape Caulerpa, but never heard of apple algae.. Heehee! Could have a tutti-frutti mix!> and toadstool algae <Have not heard of this one either... do you have scientific names for either of these?> as well as whatever will grow, some hermits, a few snails, a coral banded shrimp and a Stomatella and 2 lettuce nudi.s. It's a standing pond refugium, without any circulating water, just the air stone. <Interesting, not sure I understand the point. It is not connected to you main system?> It's 20 gallons. <OK.> I have a lot of odd things in there...lots of little red things stuck to the sides of the tank <Could be a type of tiny spiral tube feather duster (Spirorbis)> nd a lot of white and see through caterpillars on the apple algae crawling around... <My guess is a scud, a Gammarus shrimp.> an odd protozoan type thing every now and then, but tonight something new happened. <OK.> I have been privy to something odd hatching. <Neat!> 3 to 5 are in my tank as of tonight, and they are small, crystalline creatures with many arms. They swim just like jellyfish. They do adhere to the algae on the front of the aquarium and often swim around and then reposition themselves. Sometimes they go into the algae instead. I do not know what these are. They are totally cool however. They swim exactly like jellyfish and I have included some images. <I see.> Can you identify these? <Is a hydroid Jelly (Staurocladia oahuensis). Nothing to be concerned about. They typically come and go. More here: http://www.wetwebmedia.com/jellyidfaqs.htm http://www.ronshimek.com/Animal%20Groups%203%20Cnidarians.htm > <Welcome! Mich>

Aiptasia, or something else? Something else: Hydroids! 10/11/07 Hi! <hi there!> I've been reading your site for about 6 months now and it has been wonderfully helpful in identifying and learning to care for all the creatures in my aquarium. <Terrific!> There is one I haven't been able to identify, however. They grow in clusters and have long, skinny brown stalks (about ½ inch long). <Uh oh> There are around 10 or 12 tentacles which are very fine and wave constantly in the water. <Yep> I have seen Aiptasia in my tank and have removed it, but these look different. Can you identify these and please tell me if they are good or bad? <I'm sorry to say that they're hydroids and they are definitely bad.> I pulled about 50 of them off the rock yesterday with tongs and then remembered your admonition about pulling Aiptasias off of rock. I hope I haven't caused these to multiply horribly! <Although such removal is a very bad thing to do with Aiptasia, the same is not true with hydroids. The best method is to manually remove them at the base with tweezers. Just be sure not to touch them as you might get a nasty sting! Please see these links (and related blue highlighted links at the top) for more info re: http://www.wetwebmedia.com/hyzoancompfaq.htm http://www.wetwebmedia.com/hyzoanidfaq2.htm Good luck. I wish I could have given you better news! Take care --Lynn>

Can you ID this?   9/27/07 Good morning! <Good morning!> I hope this email finds the men and women of WWM well. I had a quick ID question I'm hoping you can help me out with. I have this stuff growing out of a patch of zoanthids in my 12 gallon nano. It seems to have just shown up out of nowhere. At first I thought it must be some kind of algae, but when I poked at the zoanthids to get them to close so I could see what kind of base they had, they balled up as well. In the second picture you can see how they closed up, and also that they seem to be growing from "runners" like crabgrass as opposed to from a mat or encrustation like GSP or xenia (two possibilities thrown at me on a reefing forum). I have looked at both algae and coral pictures on WWM and Google trying to get an idea, but I'm at a loss. Do you know what it is? <"Brown" or "pom-pom" hydroids: http://www.wetwebmedia.com/hyzoanidfaq.htm> Is it good/bad/indifferent? Should I pull it out? <yes> Thanks for any help you can give. <No problem, Sara M.> P.S. If you need me to attach the actual pictures instead of links, please let me know. http://farm2.static.flickr.com/1080/1447354271_5fdfde9b62_b.jpg http://farm2.static.flickr.com/1010/1447117139_4ed34bd05b_b.jpg

Baby Mini Brittle Star? Nope, Hydroid Jellyfish! 8/19/07 I was wondering if this was a mini brittle star. <Nope, it's a teeny tiny crawling hydromedusae (Staurocladia oahuensis) and generally nothing to worry about. Please see these links for photos and more information: http://www.wetwebmedia.com/jellyidfaqs.htm http://www.ronshimek.com/Animal%20Groups%203%20Cnidarians.htm <Take care -Lynn>

Hydroid(?) ID 8/10/07 <HI Jason, Mich here.> I think I incorrectly linked the images. Sorry. <No worries! I see them now.> http://picasaweb.google.com/jasonm1/AquaMisc/photo#5096085357812969394 http://picasaweb.google.com/jasonm1/AquaMisc/photo#5096085314863296418 Hi Crew, <Jason> I hope you can help me identify these brown hydroid-looking creatures. <I think you ID'd them yourself! Can see similar on this page: http://www.wetwebmedia.com/hydrozoanfaqs.htm > <Welcome! Mich>

Mystery Algae or Invert, Hydroid ID  -- 07/14/07 Hello, my name is Michael. <Hi Michael, Sara here.> I have recently found a large number of strange little creatures in my tank that I was hoping you could identify. <The pictures are a bit blurry, but they look like hydroids.> Here is a little information about my tank in case it helps. I recently upgraded from a 30gal to a 55gal tank (definitely worth it). I had a slight algae bloom when I changed to a higher wattage of lights about 2 weeks ago. I just got back from a 6 day vacation and everything seemed OK. The algae had disappeared, all parameters were normal, nice reddish/purple coralline was growing on my new rocks, my corals seemed bigger and healthier, and I had some nifty colonies of small yellow feather dusters. <Cool. Well done.> Anyways, I then noticed some strange creatures on the shells of my Cerith snails and in a few rock crevices. I apologize that I couldn't get better pictures so ill try to describe them. These things are very, very small with a tanish stalk, white center at the top, and several small tentacles around the top. They seem too small to be glass anemones and have no calcium tubes like feather dusters. After a long search on your site I was unable to find any information although I could swear I had seen a picture of these things a couple months ago while skimming through your archives. <Try here: http://www.wetwebmedia.com/hyzoanidfaq.htm I think at least one of those pictures is one of hydroids similar to yours. But they come in a lot of different shapes and sizes. Some look like jellyfish while some look like hairy strings, algae or skinny little aliens. See here too: http://www.wetwebmedia.com/hydrozoans.htm> I only ask because my experience with mystery creatures has been that they are either beneficial or very bad. Are these creatures some sort of invertebrate, algae, or something else? <If they're hydroids, they're closer to jellyfish.> Also, are these creatures harmful and if so, are there any ways to get rid of them? <It just depends on the kind you have. A lot of hydroids never become a problem or a nuisance. However, some other become quite a pain to deal with. For right now, I'd just keep your water quality good and wait and see if they go away on their own.> Sorry if this has been answered before and thanks for your time. <No Best,
Sara M.>

Macroalgae ID   7/13/07 Greetings, Hey Crew! I have a couple of pictures of an unknown Algae that I was hoping you might be able to ID. <Actually, I think you have hydroids (most likely of the genus Myrionema). Not all hydroids are bad, but these ones are. And believe it or not, they're actually closer to jelly fish than algae.> This stuff is incredibly prolific and comes right back after harvesting from the rock. I'm afraid I would have to scrub the rock to get it off and as almost every rock has some other important denizen, I'd rather not. Harvesting is not a problem but I was hoping with an ID, I might find a critter who would benefit from harvesting it for it's own nutritional needs. <I hate to be the bearer of bad news, but these things get really annoying. You're not likely to find something that eats them. They sting and kill things. Basically, they're like Aiptasia. For more info, please see: http://www.wetwebmedia.com/hyzoancompfaq.htm.> Thank you, <De nada, Sara M.> EL

Re: Macroalgae ID, hydrozoan control   7/13/07 Sara, I looked through what available literature there was on this species that I could readily find as well as cruising through the WWW forums. From what I read, short of removing the rocks and scrubbing them off, I am basically going to be in a situation of just constantly harvesting them out and trying to keep them from growing near any corals. <Pretty much, yes. Controlling excess nutrients with protein skimming, water changes, macro algae harvesting, etc. will also help.> However, I noticed that in a previous post Anthony mentioned that some limpets eat them. I was wondering if there was a way we could get his attention and find out a suggested suitable species that I could add to the system to enjoy a wonderful Hydroid snack!?! <I'll cc dear Anthony here. He's extremely busy so I don't know how long it might take him to respond. Also keep in mind that knowing the kind of limpet that eats these is one thing, finding them is quite another.> Again, thank you so very much for all your wonderful help! <Happy to help. Good Sara M.>

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