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FAQs about Red Algae/Rhodophyte Identification 1

Related Articles: Red Algae in General, Coralline Marine AlgaeAvoiding Algae Problems in Marine System, Algae Control, Marine Maintenance, Marine Scavengers, Snails, Hermit Crabs, Mithrax/Emerald Green Crabs, Sea Urchins, Blennies, Algae Filters, Ctenochaetus/Bristle Mouth Tangs, Zebrasoma/Sailfin Tangs, Skimmers, Skimmer Selection, Marine Algae, Coralline Algae, Green Algae, Brown Algae, Blue-Green "Algae"/(Cyanobacteria)Diatoms, Brown AlgaeAlgae as Food

Related FAQs: Red Algae ID 2, Red Algae ID 3, Red Algae ID 4, Red Algae ID5, & Red Algae 1, Red Algae 2, Red Algae 3, Red Algae in General, Red Algae 2, Red Algae 3, Red Algae Behavior, Red Algae Compatibility, Red Algae Selection, Red Algae Systems, Red Algae Nutrition, Red Algae Disease, Red Algae Reproduction/Propagation, Coralline Algae, Marine Macro-Algae, Use in AquariumsAlgae as FoodMarine Algae ID 1, Marine Algae ID 2, Marine Algae Control FAQs II, Marine Algaecide Use, Nutrient Limitation, Marine Algae Eaters, Culturing Macro-Algae; Controlling: BGA/Cyano, Red/Encrusting Algae, Green Algae, Brown/Diatom Algae


New Print and eBook on Amazon

Marine Aquarium Algae Control

by Robert (Bob) Fenner

Red Hair/Branching algae - Ceramium 5/31/04 Hello Bob, <Anthony Calfo in his stead> I hope you're well and in a good shape. <the more years that go by with me working in front of a computer, the rounder I get. I'm thinking of strapping my laptop to a treadmill <G>> I'm ok too, it could be better but it could be worse.... <keep on keeping on my friend> I have received a question about : "red algae Ceramium (???, do you know this algae?) <the correct spelling is Ceramium with an "m". It is a nuisance species... one of the many things called "red hair algae". This one really is a doozy though. It naturally occurs in high nutrient near shore environments and often lives as an unwelcome epiphyte on other critters and substrates> The aquarist has a wild growth of these algae and can't get rid of it. <no worries... it can be controlled. Easily starved into submission with tighter nutrient control. Really... it can disappear in 2-3 weeks with wicked protein skimming. It probably got there because of poor protein skimming, weak water changes and/or weak water flow which allowed sediments to accumulate> He asks for my help.  Al seems to be good in his measurements but he has a Ca test of 600, to heavy I think. <I doubt that the reading is even accurate. Indeed too high. And if his Alk is not very low, then I am sure it is a misreading. Else, the poor chap is having a precipitous snowstorm as we speak <G>> I ask for my help and I ask for the help of the supreme chancellor.... <Hmmm... yikes! And we've just been calling him "Bob" all along.> He said he had a problem with his Ca reactor a while ago, what he did to help the problem, he didn't say, perhaps is the solution knowing what he did.... Read You. Regards, the best. Claude <Claude, do suggest in concert with starving the algae out, some Diadema urchins (Pacific or Atlantic species). They will only be treating the symptom and not the problem, but will give results fast. They are marvelous algae grazers. One small urchin per 100 gallons if you want to be conservative. Prost! Anthony>

Nuisance red algae 4/5/04 Hey Anthony and Bob - I don't know if you remember me but I am from the Rocky Mountain Reef Club in Colorado and we had you guys come out and speak with us.   I also work with Barry at Aqua Medic and handle all his website development and talked with you about wetwebmedia.com. <cheers to all the Denver gang... especially that sweetie Becky at Neptune's <G>> I am having a very annoying algae bloom in my tank and I don't know what it is or what I need to put into the tank to eat it or what I need to change to stop it. Here is a picture: http://www.johnsreef.com/images/red_macroalgae.jpg Any information would help.  I would really appreciate it! Thanks! John Michael <decent picture, but just not clear/close enough to make a confident ID. Looks like it might be the dreaded red turf algae, Polysiphonia to me. Do research that name (know that there are many forms of it... stick to the hobby pics/sites.) Best regards, Anthony>

I think its a kelp??? <A red algae of some sort. Please read here: http://www.wetwebmedia.com/redalgae.htm and on to the related articles and FAQs files (linked, in blue, at top). Bob Fenner>

Botryocladia likely. RMF

Red Alga ID 11/6/04 Once again need some expert opinion.  I have this red algae grew in both the overflow and sump.  It attached on side of wall in high flow area.  Any idea what type red algae it is.  Is it Nemastoma sp.?  As always thanks for the help. Wayne <its always tough to ID from a pic, but in this case not possible. The image is just not close/clear enough to examine. I can tell you that it does not look anything like Nemastoma to me. Do browse the database algaebase.org for more pics/info and also consider any of the excellent books like the Littlers (find them at seachallengers.com). They are experts on Marine algae. Anthony>

Red Algae ID 10/9/04 Okay, I found this picture on your website, its not mine but this is exactly what is growing so prolifically and acting as home to my clown.  Would you take a shot at it.   <Halymenia or Kallymenia IMO. Please also take note of the excellent database "algaebase.org"> I am so fascinated by it. No emperor, huh?  I want a big hardy fish, Koran?  Blue face?   <they are all too large/difficult. Anthony>

Where Did That Ogo Go-Go? (Mystery Gracilaria ID) Hi, <Hi there! Scott F. at your service!> We received a type of Red Gracilaria that differed from the branchy type in that it was rather flattish, somewhat transparent and "slimy."  Our tangs loved it and it seemed to grow better than the thin branchy type.  I found a picture at one time that indicated the species was from Japan.  The Caulerpa smothered it out and of course I can't find the picture/type now. Any idea what the name of it was or where it could be obtained? Thanks, Doug <Well, Doug- I believe that I have encountered this species before, myself. I think that it may be G. salicornia, but you may need to do some internet searches to be sure. University of Hawai'i maintains a nice database on macroalgae with links that may be of interest...I highly recommend checking it out. Best of luck on your search! Regards, Scott F.> <<There are dozens of species of Gracilaria... RMF>> Re: My reef tank plans I do not know if you needed the original email or not so I keep it, sorry if it causes any problem. Just want to pass on this info on red Gracilaria tikvanhie. <Thank you for this... couldn't find on the Net... as you've mis-spelled the scientific name... twice!> You had said you never heard of this species. I know you guys always like new info.  http://www.hawaii.edu/reefalgae/invasive_algae/rhodo/gracilaria_tikvahiae.htm  Thanks for the fast reply. Gary <Thank you for the reference. Bob Fenner>

Red algae - 05/05/2006 I have had an issue with red bubble algae for sometime now. By searching the FAQ I initially thought it was Botryocladia. I now am not sure of this. Reasons being that in other responses it was said that many predators would feed on this and it would disappear soon. <Sometimes...> I have had the problem for nearly a year now and it is worsening. Though I do not have a picture of this I can tell you that it does not grow on a stalk or vine like the Botryocladia in pictures I have seen, but rather directly on the rocks, filters covers and even snail shells. I have tried manually removing the bubbles but while attempting this I popped a bubble and a gel was secreted. <... this is likely a blue-green algae... not a Rhodophyte> I can only guess that this is how the algae reproduces because it spread like bird flue after that. The best way I can describe the culprit is to say it looks like a strawberry. Any ideas or predator suggestions would help. <... do you have access to a microscope of two hundred plus power? Bob Fenner>

Red algae ID Hi Bob, It's been awhile since I have drawn upon your knowledge . I figured it was about time to do so again so today I bring you an algae question. What I have is variegated in color, ranging from pink to dark blue/purple. It grows rapidly , and does not seem to care where. It is soft and spongy and does not readily "pop" when squeezed between your fingers . It grows in small oval disc's stacked close together and on top of each other sorry for that wonderful description) in a bunching fashion. Any Idea what it is and how to control it . <Hmm, stacked as you say, sounds like Halimeda, but soft... a Botryocladia species..? the color range? Perhaps due to other algae growing on its segments (corallines, greens, blue greens... Just pinch, cut off the masses of it you don't want and remove> The tank has a refugium with lots of Caulerpa in it .Thanks for your time. <Be chatting. Bob Fenner> Jim Bell

Something growing in my reef (spiky, reddish, not moving... mmm)  ID Hello Mr.. Fenner my name is Tori and I work with a fella named matt who told me to email you about something I have growing in my reef. <Okay> I don't have a scanner or I would send a picture, first let me tell you what I have running.. then I will describe the organism. I have a twenty nine gal. SeaClear tank, aprox.35-40 lbs of live rock with various things on it.. green stars, mushroom anemones, leather coral, yellow polyps, green buttons, x-mas tree rock.. torch coral, mandarin dragonet, yellow eye tang, maroon clown and two Tridacna clams. <Wow, quite a bit of life in such a small volume of water> what has me baffled is this thing that looks just like fire, that started growing really good when I put some light on the tank, it grew when I only had 40 watts on it <a marine glow, and a power glow> then I put two 55 watt power compacts on it as well.. now it is really growing. as I said it looks like fire, with the outside surface being bright red and very smooth.. branches growing from the base are sharp on the end, and spiky like a drawing of fire would be and the inside surface is bright orange. it seems to be rather ridged, moving in the strong current but not much. its still sort small only about an inch or so tall but branches are still growing. there are no visible polyps or tubes. it is really magnificent I must tell you... one of the most beautiful marine things I have ever seen! I can not find a picture of this thing, or anyway to find out what it is. I think I may have another growing across from the first one, but it still looks like a bud now on the rock. I am in the business of selling fish so I have some good equipment on this reef: Rena Filstar xp1, 90gal. Berlin protein skimmer, two Rio powerheads and one power sweep at the top <to keep the stars happy!> live sand, and coral. this tank has been running for at least two years.. I hope you can help me.. matt said you were the fish guru! thank you, Tori Craig <Thank you for writing. Don't know exactly of course, but what you describe sounds like some sort of red algae (Rhodophyte). Please read here: http://www.wetwebmedia.com/redalgae.htm and the coralline algae article thereafter. Please have a friend with a digital camera take a few shots to send along. Bob Fenner>

What in the heck is this? (red algae) Greetings! <and Salutations... Anthony Calfo in your service> I was wondering if you could help identify this thing growing on my rock. It came in on the rock and I figured it would just die as it was shipped from Fiji and did not look that great. For size it is about the size of a baseball. There is also a branch or two on other spots on the same rock. I have enclosed some photos. Thanks! If the photos don't help, it is maroon colored and fuzzy. Thanks! <Adam... in general terms, you have a calcified red algae species. Guessing to the generic level, it is like Galaxaura although I only know of it from the Atlantic. Are you certain it came in with Fiji rock because the rock in your pictures resembles Atlantic/aquacultured rock (which would make ID down to genera more akin to the aforementioned Galaxaura)? Nonetheless... a very nice branching and partially calcified alga. Cool. Anthony Calfo>

Red Algae... but not a Rhodophyte... Bob, This red slimy algae has showed up on this piece of live rock. It seems to be spreading. Any concerns and do you know what it is??? <Yes to concerns... this is almost certainly a type of BGA/Cyanobacteria... please read over its biology, control on WetWebMedia.com perhaps starting here: http://www.wetwebmedia.com/bluegralgae.htm and the links, FAQs files beyond. Bob Fenner> Thanks in advance.
John Kummer

Coral I.D. (actually a red algae) Hi The Crew, <Howdy> Hope you guys enjoyed the hot summer. I have this thing growing out on one of my live rocks about two months ago, now it grew to about 4" around. It feel soft at touch, and the appearance like Japanese maple tree. Would like you guys to identify it for me. As always appreciate your expertise. <It's a species of Red Algae. Please see here: http://www.wetwebmedia.com/redalgae.htm> PS: Just thought you might interest to see this picture: One of my tomato clown in a purple tipped Condylactis anemone. SWEEEEET. <Very nice as well. Bob Fenner> Wayne

Algae/Coral I.D. Hi The Crew, <Hi the fellow fish nerd> Hope you guys enjoyed the hot summer.  <I'm thinking about shaving my entire body... heat index is over 100 here in Pittsburgh with serious humidity. Sneeze and it triggers a thundershower> I have this thing growing out on one of my live rocks about two months ago, now it grew to about 4" around. It feel soft at touch, and the appearance like Japanese maple tree. Would like you guys to identify it for me. As always appreciate your expertise. <it is clearly a red algae species... very attractive to me. Enjoy it!> PS: Just thought you might interest to see this picture: One of my tomato clown in a purple tipped Condylactis anemone. SWEEEEET. Wayne <with kind regards, Anthony>

Cool Marine Plant... Where're those pix!? Hi, <cheers, mate> I have done search after search in every location I can to identify something that is taking over my substrate. I hate to bother you with questions but I have looked everywhere and I am starting to worry at this point.  <no bother... and no worries> The first thing that I saw was this purple anemone looking creature that is attached to a live rock.  <actually a fluid/bulbous red algae species> It doesn't seem to have a stalk, but just little stubby arms waving around. It has the diameter of a nickel and is no more than a centimeter high (and growing). Here is a picture. I wasn't worried but then around the same time that he popped up 30-50 of these other little guys popped up.  <cool...> They started small, about the size of a pen head, but some have grown to the size of a pencil eraser or slightly larger. While the first one was on top of a rock (I guessed that possibly the first one on the rock is the same species and spawned the smaller ones), these little guys are only on the substrate. They are round balls with little dark spots that might possibly be stubby arms. Here is a picture of these guys.  I think I can collect them if I have to but if they are good to have or won't do any harm, then I don't mind them.  <no harm at all... likely you have or can easily find an herbivore to graze them down if you like... else enjoy!> This is a FOWLR tank. I GREATLY appreciate your help and your faq's are a bible to me. Hope all is well, Andy <our pleasure... with kind regards, Anthony>

Red Algae species ID Hi everybody! <Cheers, my friend!> I just bought my first plant for my FO aquarium. It is a beautiful red plant. <specifically... it is a red algae species... perhaps Halymenia. Do use that genera name to search for more photos on the web> The problem is that neither I nor the shop owner know what kind of plant it is (its name, peculiarities, etc). I am sending you a photo taken by my camera (the analysis is not very good) in case you can identify it. <alas... without knowing where it was collected from and from the vagueness of the photo... I cannot not be sure. Halymenia is a good guess though> I intend to buy some live rock as well. Since I have tangs and angels, will they eat all the green of the live rock? <most of it yes... resist buying tangs as long as possible (many months) to allow the algae and plants to establish very strong first> If yes, then is it still worth to buy? <yes... but it is better off placed in a fishless refugium inline> Thanks, Thanassis from Greece
<best regards, Anthony>
Red Algae IDs 8/2/03 Hello!  Who do I have the pleasure of writing to today? <Antoine... with cape but no sox tonight> I've searched through the WetWebMedia faq's but I haven't been able to identify two of the items growing in my nano reef. Attached are two pictures.  The item in picture1.jpg started out as a totally flat red spot on my LR.  It kinda looked like coralline algae... <nope...> but it has grown out rather fast into its present state. <it is Nemastoma... see page 104 of Reef Invertebrates for pic, and page 106 for brief PP> The item in picture2.jpg started out as a heart shaped "balloon" and has grown at about the same rate.  It is filled with what looks like air bubbles. <tough to say for how small it is and until it grows out more. Does resemble Scinaia. Could also be Botryocladia. Do seek more pics and info on algae at algaebase.org> Any help you can offer in identifying these two mysteries would be greatly appreciated. Thank you all for sharing your knowledge & helping me with this educational/enjoyable hobby! Jason M. Wood <our great pleasure... thank you for sharing your pics for us/the public to see and learn from. Anthony>

Algae ID 10/20/03 I have searched all over to find something that looks like this but to no avail. Have you any ideas? I think it is some form of algae. It has grey "arms" with dark brown stubby bits which would be polyps on a coral - growing well near the surface of the tank under the T5s. Came with some coralline LR and has grown several arms in the last week of about 1-2" long in a sideways spreading habit. What is it? What do I do with it? <its a Red algae (Rhodophyte) of the genus Laurencia or perhaps Halymenia. Tough to tell from the unclear image and small nubbins of a specimen. Generally harmless although any macroalgae can be a nuisance if the nutrients are high enough in the system. Doa search at www.algaebase.org and see if any pics look familiar to you. Anthony>

Help identifying saltwater plant: Red Seagrapes - Botryocladia 11/2/03  Hi, I love your site...many thanks. I've searched around trying to identify this plant, but haven't found any good leads. All I know is that the Chinese name translates to 'Red grape tree'. Hope the picture helps, Thanks Again Craig  <very fine picture... clearly a Rhodophyte of the genus Botryocladia. We discuss this and most marine algae extensively in our new book "Reef Invertebrates". Please also consider bookmarking algaebase.org as an excellent reference. Best regards, Anthony> 

Red macro-algae ID 1/30/04 Could you help me ID these?  I've been all over your site, but nothing jumps out at me.  Thanks in advance for your help.  Jennifer <Hi Jennifer.  Adam here.  Wow!  Kudos on your successful cultivation of such beautiful specimens.  The first pic (grape looking) is probably Botryocladia sp.  The last one (sort of feathery) is probably Gracilaria.  The middle one (finger shapes) is a stumper, but could be Codium.  HTH.  Best Regards.  Adam>
ID Red Balloon algae? 12/30/03 Any idea what these are? They keep getting bigger and bigger - look like they may pop someday. http://www.geocities.com/jtgilkeson/baloons.html Thanks! <could be the rhodophyte/red algae "Botryocladia". Do a search for this genus and others at algaebase.org to see more pics. We also have several images of this algae in our Reef Invertebrates text. There are differences in color/morphology among those species/specimens seen in the hobby. Anthony>

New Print and eBook on Amazon

Marine Aquarium Algae Control

by Robert (Bob) Fenner

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