FAQs on Identification of
Related Articles: Cnidarians,
Water Flow, How Much
Related FAQs: Cnidarian IDs 1, Cnidarian IDs 2, Cnidarian IDs 3, Cnidarians ID 4, Cnidarians ID 5, Cnidarians ID 6, Cnidarian ID 7, Cnidarian ID 8, Cnidarian ID 9, Cnidarian ID 10, Cnidarian ID 11, Cnidarian ID 12, Cnidarian ID 13, Cnidarian ID
14, Cnidarian ID
15, Cnidarian ID
16, Cnidarian ID 17, Cnidarian ID 18, Cnidarian ID 19, Cnidarian ID 20, Cnidarian ID 21, Cnidarian ID 22, Cnidarian ID 23, Cnidarian ID 24, Cnidarian ID 25, Cnidarian ID 26, Cnidarian ID 27,
Cnidarian ID 28,
Cnidarian ID 30,
Cnidarian ID 31,
Cnidarian ID 32,
Cnidarian ID 33,
Cnidarian ID 35,
& Anemone ID 1, Aiptasia
ID 1, Stony Coral ID
1, Mushroom Identification,
Soft Coral ID, Alcyoniid ID, Xeniid ID, Cnidarians 1, Cnidarians 2, Cnidarian Behavior, Cnidarian Compatibility, Cnidarian Selection, Cnidarian Systems, Cnidarian Feeding, Cnidarian Disease, Cnidarian Reproduction,
Symbiotic Reef Invertebrates to Captive Lighting,
Red algae ID 2/11/18
Hello, I wrote in many months back and you were super helpful identifying some
algae for me. I hope you can help again! I have attached a photo of the reddish
pink tree-like algae that is spreading like wildfire through my tank. I didn’t
see anything like it in your algae ID archives... can you tell me what it is?
<I wish I could... the regular branching... I don't think this is an algae/Thallophyte,
but a very pink Hydrozoan of some sort>
Does anything eat it that I could use to help control the spread? Thank you!
<There are some notable Seaslugs that ingest various Hydropolyps, but I don't
know anything re this particular one. I would remove it from the system, as it
may be producing stinging elements that will bother your other livestock. Do you
have a microscope with a USB connection? I'd like to see some 100-200, 400 time
magnification shots. Bob Fenner>
Re: Red algae ID 2/12/18
Hi Bob, I don’t have a microscope unfortunately.
<Perhaps a local fish store does, someone from a marine aquarium club>
I have tried some manual removal but ripping it off leaves traces behind
that I cannot remove, and it is widespread, including my tank overflow box
and powerhead. It also grows very very fast.
<Yeeikes! I wish I could tell definitive what this is. I have never
encountered something this shade of pink, nor with the array of branching it
Is bleaching my tank and starting over my only option to eradicate this
<It may well be>
Also, can it sting fish or just corals?
<Can't tell w/o testing or microscopic looking. BobF>
Salt Water Identification Assistance
Hoping you guys can help ID a new found presence in my aquarium.
Thanks! Chad H.
<The whitish bit? Have cropped, spiffed about as well as I can... appears to be
a bit of octocoral... likely a soft coral of some sort. You could excise. Bob
Cnidarian id 5/26/17
Hi, Guys! A friend of mine, who's an avid reefer and has been skin diving
for the past 20+yrs, has discovered this rare Cnidarian. It's his first time
encountering this beautiful creature. We think it's an anemone as
the physiology greatly resembles one. The bottom is glued to the
rock like an anemone, not like a soft coral. He collected this off
Negros Island in the Visayas, Philippines, and it's the only one in
the entire area where he dived 2 days ago.
It's photosensitive as it moved the black ruffle like tentacles when shone
with a flashlight. It has what look like sweeping stinger tentacles buried
underneath the black ruffles. The guy who discovered it, gently poked it
with his chipping hammer to see if it reacted violently, but nothing
happened, so he touched it with his finger and it didn't sting. What do you
guys think it is?
<Does look to be an Actinodendron sp.; have seen a few such possibilities
recently. Often called "Hell fire" anemones> Examples of larger ones here on
It would be awesome if it's a never before seen species. Hehe.
Hoping for an id,
<Thank you for sharing. Bob Fenner>
Mushroom coral question 2/18/17
<12.5 megs; no rdg.>
Hi all. I wanted to ask what species of coral you think this is?
<Beauties... Discosoma/Actinodiscus of yore>
They are mushrooms which are photosynthetic with branch like tentacles- they
also enjoy consuming little lumps of fish meat about (1.5mm size) and will close
up and eat them. (Enclosed picture) The internet seems divided between ordinary
furry mushrooms or elephant ear. Also if they are accidentally touched (even
lightly) or disturbed they split within a day and then I have more!
At their largest I would say they are just under 3" long each. (I have had them
in my tank for about 4 years and have given away a fair few)
<Good of you>
Are their different colour variations? I would love to have more. Thanks!
(And please excuse the algae switched off sump and a missing fish has upset the
system a bit)
What is this? 6/3/16
I purchased this from my LPS about 6 months ago. I though it was a sponge,
but it isn't. It seems to be growing rapidly and if I put it somewhere it
doesn't like to be it can expand to move itself from the crevice. Any idea
what it is....does it pose any threat to my saltwater tank (given off
toxins, etc.). Your expertise is appreciated.
<?! This is a soft coral... a Nephtheid.... See WWM re... your system must
be optimized and stable... for it to be doing this well. Bob Fenner>
Nem? I.D. 4/28/16
I was wondering if someone could help me identify this animal. It appears to
be some sort of rock flower nem, but is missing some of the normal features
of a rock flower nem.
<Mmm; not this. Almost look like Zoanthids, but more than two rows of
They are about 1" across, do not appear to sting the corals around them, do
not seem to "walk" around, and do actively feed on mysis shrimp and other
If you could help me identify them, then I can be sure that I'm giving them
proper care. Thank you very much for your time!
<These appear to be some sort of Anemonia sp. to me. Bob Fenner>
I have a ball of Chaeto Macroalgae that I have kept for a couple of years. It
was a start of a few threads and now the size of a large softball. So my
question relates to majano type anemones as my Chaeto seems
to have two majano anemones growing in the outer most threads of the ball.
It is my understanding that majano anemones only grow on hard surfaces. If so,
then what do I have?
<Perhaps another form of polyp/oid life. Send along a few Kbyte size,
well-resolved image if you can. Bob Fenner>
Re: Chaeto visitors
Sorry but the mystery has vanished after I prodded them with a chopstick.
The next day they were gone! I cannot I don't them anywhere in the tank.
Thanks for the help.
Hello crew! I started up a 90 gallon a few weeks ago and it is still currently
cycling, but I think I have hydroids. They are very small, attached to all the
walls of the tank, and look like tiny hairy tan balls almost. They do not
respond to touch, and the stalk like base that they are attached to is not any
larger than the other parts. I have attached a
picture, I apologize for the terrible quality but it is the best I can get with
<Do these look characteristic when looked through magnification; as in through a
loupe? Do appear Medusoid...>
Any help with identification and what exactly to do with them will be greatly
appreciated. I'm also dealing with Aiptasia and flatworms( acoela I think), so I
am hoping for good news but fearing the worst. Thank you so much for your time!
<Mmm; well; you could just wait; see if all "settles out" with time (weeks)
going by... with a lack of feeding, nutrient, perhaps even blanketing the system
to greatly reduce light penetration. IF greatly concerned a physical filter,
like a diatomaceous earth... can be set up to filter out most all; again, over
days time. The most extreme methods involve over-heating the system; poisoning
it... but these can/will damage the live rock, organisms in the substrate. For
me, I'd just be patient for here, now. Bob Fenner>
Hi! Need advice on coral ID, pico reef stocking
Hi Bob, guys and gals,
Thanks for maintaining this wonderful website! Over the course of my hobby,
it has proven time and again to be a most valuable resource.
Here in Singapore, my colleagues and I are in the process of setting up a small
8.3 gallon pico reef tank. Purely for boosting morale among our
coworkers you understand :)
Sometime last week, we added a chunk of live rock with four of what we suspect
are colonial anemones of some kind. At the LFS, the rock had been in a tank with
another piece with many more of these anemones.
In the two days it has since spent in our tank, the heads of each polyp have
expanded to be about 5cm across. This really varies though over the course of
the day, depending on the light intensity, but 5cm appears about the average.
From what I can tell, the stems of each polyp are completely separate from one
another and are spaced approximately 10cm apart. They seem attached deep within
the crevices of the rock. Seen under blue LEDs, the stems, each about 1/2 cm
thick, bear fluorescent green ovoid spots.
The polyps appear extremely responsive to external stimuli, expanding within 30
seconds of the lights coming on, and reacting immediately to touch or changes in
*We'd love to hear your input on identifying these critters, as well as any
considerations we might need to take to keep them healthy.*
The polyps do not seem 'sticky' to the touch, which we hope to mean they might
not pose too much threat to livestock we hope to add in the future.
On the subject of future plans, we are debating perhaps a trio of Sexy
Shrimp (*Thor amboinensis*), and perhaps an anemone crab (*Neopetrolisthes
*Would the crab turn aggressive due to competition for host anemones? *
<Not likely, no>
We are also researching the viability of a small Royal Gramma (*Gramma
loreto*) as the sole fish. *Would this be wise, bearing in mind this
need not be a permanent arrangement* (I have a separate 210 gallon system it
be moved into when it outgrows the pico. *Can it also be relied upon not to
inhale the Sexies? *
<This volume is a bit small for Grammas>
Would love to hear your thoughts on the mystery anemones (pics attached) as well
as our future plans for this tank.
Thanks in advance, and keep up the great work!
<These appear to be Anemonia majano or similar. You can search/read Re them on
WWM, the Net. I really like them... but some folks find they over-reproduce....
Re: Hi! Need advice on coral ID, pico reef stocking
Thanks for the quick reply!
I find the anemones rather pretty, and very fascinating to watch.
We will read regarding the anemones, and reconsider the gramma.
Much obliged to you for your time.
<And you; BobF>
softie Acan hitchhiker 1/28/16
Can anyone ID this? I have found three people who have this hitchhiker, always
on an Acan it seems. Mine is a softie ;not a clove, palm tree, pipe organ,
xenia, anthelia, daisy or anything else I can find a name for.
<... the Clavularian in this tiny pic?>
[image: Inline image 1]
thank you for any help you can offer,
Rebecca A Linden
Re: softie Acan hitchhiker 1/28/16
Thank you, this one does not seem to match any species pictured there?
<There are many... >
It has no hard pipe, so not a pipe organ. It has no spot in the center, so not
GSP. very slight to no dissection in the "petals" so not a clove. More "petals"
than a daisy.
<Still a Clavulariid almost certainly. BobF>
Unknown coral branch... thing.
I received what appears to be a piece of some type of branching coral that
I cannot identify.
It's green with a purple cast to it (or visa versa) and has a number of
widely separated polyps. I have not seen them open.
<Mmm; what does this thing feel like? Is it at all flexible? If so, my
tentative group vote is going to a Rindkorallen; a Gorgonian>
It kinda looks like the antagonist from Day Of the Tentacle, which would
awesome if true.
Re: Unknown coral branch... thing.
No, not at all flexible. Here is another pic, and a pic of the hard internal
structure at the fractured end.
<A branching Scleractinian of some sort.... many Families possibilities.
Have to wait till it's larger and more close up pix of corallites to tell more.
Re: Unknown coral branch... thing.
Hi All.... myst. "coral" bonus!
<Tab; twelve megs of pix? Groan>
I was searching for information on a mystery coral and came across your
I just set up a tank to start cycling and bought a live rock that
was taken from an old tank at the store. After getting it home we noticed
what looked to be a whitish slime on it going to rinse it off i noticed
opening thinking we had a stray coral i just put it in my tank. It has
recently opened more and i wanted to get it identified to make sure it
harm any other coral or fish i will eventually place in the tank. it has
only been in the tank for about a week.
These picture were taken within 20 min of each other
<Interesante.... in cropping, spiffing up.... this looks like a Haddon's
carpet anemone..... striated; uniform tentacles as small bumps uniform over
capitulum.... What say you? Bob Fenner>
Coral ID. Majano-Ville! 8/18/15
Can you identify this coral for me? It has grown at such a rate its on all my
rich <sic, rock> and even grows to the glass -lots of free coral :)
I thought torch or galaxia but it really has no sweeper tentacles to speak of.
It's more of single polyp coral with a full head like a Zoa...but with the
bulbous tip its.... Aaaaah, I'm so confused! Lol
<Looks like the pest Anemone Anemonia cf. majano.... See WWM re. Bob Fenner>
Coral Identification 6/27/15
Good Afternoon Robert,
I recently purchased a coral from a hobbyist. At the time, he did not know the
name of the coral. I have looked around the web, posted on forums, and received
very different responses. As a leader in the field, I was wondering if you could
help me identify this coral (attached). It is bright orange, and quite a
beautiful piece. Its size is roughly 2" to 2-1/2" in diameter. It looks like
some type of mushroom, but I am not sure. Any help would be tremendously
appreciated as I am trying to identify it so that I can give it proper care..
Thank you for taking the time to read this email.
<Mmm; almost certainly this is a Corallimorpharian... See here:
Re: Coral Identification
Thank you very much for your help, time, and quick response! The information
is very helpful.
<A pleasure to serve. BobF>