Who is drawing lines in the sand  10/2/05
Alright.  Who is the wise guy drawing lines in the sand? <Probably the Sand Man:):)  Dana, probably have a worm of some sort, most common critter would be a bristle worm.  A flashlight about an hour after lights are out should reveal your wise guy.  James (Salty Dog)>
A fine 'top of the morning to ya'.
I have a 60liter tank set up (about 13gallons after inside measurements and
at correct water level).  I added some liverock (3 hearty looking pieces)
after it cycled and have noticed that when I wake up, there are lines or
'tracks' in the sand near the glass.  It just looks likes someone was
drawing with a pencil (I have the camera ready if it ever looks like the
Virgin Mary).  It mostly follows around the glass but there are some
curly-cues as well.  (FWIW, I don't have kids and the lady friend isn't
doing it.)  The only other known inhabitant is a Damsel (Humbug).  Is this
little guy messing with me when I go to bed or do I have a hitchhiker?  I've
tried looking for tracks back to the liverock, but I haven't spotted any yet.
Thanks again in advance!
Dana

Popeye/Invert. IDs/interested in helping/WWM  9/29/05
Hello to all.
I recently had to do a major move for my fish, a couple of days later I
noticed one of my clown's eyes was bulging.  He had got caught in the
net during the move and the water and sand was greatly stirred causing
quite a mucky mess.  So I am guessing that the Popeye was due to an
injury received, then being in the messy water for a minute didn't help.
<Well-stated>
I immediately removed the fish and placed him in QT.  It has now been
near 2 months.  I started off using melafix (hahaha-what a waste!)
<Agreed>
since it indicated that it is helpful for Popeye.
<Scam!>
Then I got into the FAQ's on this site and started adding Epsom salt (no longer adding melafix), 1
tbls per 5 gal. Wow! What a tremendous help!  So now, I realize my fish
can be in QT for quite some time, however.... when do I know that it is
safe to put him back in his display tank? The eye started to look as if
it was going to fall out, that was before the Epsom salt was added.  The
swelling went down and it has been at an idle position for a few weeks
now.  Will the eye go back into 'socket' or what should I expect in a
general scenario?
<The eye may never fully "shrink" back... If the fish is otherwise healthy, I would go ahead and return it to the main tank>
Any help would be greatly appreciated.
Another thing if you have spare time.....  
Any locations (I am looking into books as well) recommended for ID of
various growths?  I believe some of the growths to be sponges of some
sort, but there are some worms that I am unfamiliar with and a creature
of some sort that has grown out of a tube (I can not explain this one,
too odd for my vocabulary. I'm hoping the fact that it has a tube may be
helpful in guiding me, haha far fetched but I'm hopeful) But the
worms.....maybe you know this one without seeing an image.   When
looking at the rocks all you see is little thread like strings spread
out. They sometimes reach from one rock to another.  There are a great
deal of these little "strings" appearing to be a greenish color.  Upon
further inspection, these strings are attached to the top of the body of
a worm (like a mass of stringy hair)....the worms are orange in color
ranging from small to quite large.  I have taken a syringe and squirted
water in that area....when doing this, debris floats up.  It is like
these worms gather uneaten food,  and gunk and just set in it.  Thanks
for the patience in my attempt to explain.  I am looking in to a digital
camera, maybe when I do this one of you will be interested in viewing the pictures.
<Mmm, we have a bunch of Invertebrate Identification files, and Ron Shimek has done a great job of writing up guides to such unknowns and his work is largely published, accessible on the Net... additionally, he, Anthony Calfo and I have printed ID works on invert.s, and there are many such scientific and popular diving references... many of which are cited at the ends of my articles posted on WWM, and available through SeaChallengers.com, Amazon...>
Ok.....one last thing! : )
I am throwing ideas around in my head.  I am interested in starting some
sort of salt water research/business.  I don't want to jump into this, I
am still young and have lots of things to learn.  However, it is very
interesting and enticing.  I believe I could do great things with it and
would like some input as to how feasible this would be to accomplish, especially not living near a coast.
<Many possibilities... and exciting!>
What would be the best way to go about learning what I need to know (i.e. the scientific names,
medications, etc.) other than trial and error.
<T and E... too long and costly... Reap the benefits of those who have come before... read, voraciously, widely... with a discerning mind... directed toward discovering "needs" in the trade... to exploit, develop>
I am not sure exactly how you go about choosing members to respond to e-mails, and I am sorry
if I am bluntly butting in, but are you looking for any more help?  (I think that is one of the best ways for me to learn is by teaching others)....just thought I'd throw that in there while it was on my mind.
Thank you!!!!!
Codie
<Always looking for help. Please tell me/us a bit about yourself... your area/s of expertise, time availability (we have many young and not friends who have school, other commitments that they must focus on foremost)... It is obvious you have a good grasp of English, a desire to help. Bob Fenner>

White Spots On Glass - 09/18/05
Howdy!  Great site and tons of information!!
<<Glad you find it useful.>>  
Sure beats that "Saltwater Aquariums for Dummies" though that was a great beginner for us!!
<<Useful information can be found most any place if you know how, where to look.>>
I've been searching through your site and going cross-eyed from staring into my tank for most of the morning trying to find an answer to what I have growing all over my glass.  Apparently there are tons of different white spots out there!
Mmm, yes...or in your tank so it seems <G>.>>
We have the basic 35 gal, live sand and live rock setup.  The tank is approx. a year old with the live rock and sand added slowly over the past few months.
<<ok>>
Few damsels, leopard fish and a clown.
<<Hmm...I expect before long you will only have the lizard fish...>>
Now for the white dots.  The round middle is approx. the size of a pin head, some smaller and the middle of them is definitely round. They have around 9 or 10 very fine white filaments, tentacles, legs, sprouts (??) in different lengths proportionate to their body size, all the way around them, that move freely with water movement only, as the ones out of the filters current don't appear to be moving.  At first I thought copepods, but these spots are totally stationary.  After reading through your site I went down and did the scrape test with my finger and they just slid off very easily and are soft (well as soft as something the size of a pinhead can be measured).  They are noticeably multiplying rapidly and daily, so I was thinking perhaps some type of algae?? Is there white algae?  The walls of my aquarium are COVERED with them.  Any insight would be most appreciated.
<<Nothing to be worried about Andrea, going by your description I have seen these myself many times (even have them in my refugium as we speak).  I have found them to be harmless and self-limiting (feeding on the organics/detritus in your tank), will likely continue to wax-and-wane.>>
Thanks so much!!
Andrea
<<Regards, EricR>>

Identification of worms please  9/4/05
Hi, I love this site and i am a novice.  I have a 6 gallon nano, a percula, and 6 pd.s of bulbous manmade coral.  i also have a million amphipods disgusting shrimpy lookey things with legs everywhere.
Anyhow I have 2 worms red with bristles and darker one with like five tentacles at tip.  they have been harmless so far  Which are bad? why don't they eat some of these amphipods?  and how do i get rid of all the slugs??? Lots of questions sorry????
<Please read here: http://www.wetwebmedia.com/wormidfaqs.htm
and the linked files above... Bob Fenner>

What are these?  8/31/05
Hello again!
In my 55 gallon tank I have recently  noticed that, floating in the water and
crawling on the glass, were little white  creatures that were about 2mm or
1/8" long. I have no idea what these little  guys are or how they got there. Do
you have any  ideas?
<All sorts. Please read here: http://www.wetwebmedia.com/marinvind1.htm if marine, the freshwater subweb equivalent if FW. Bob Fenner>
 

The Fun in New Discoveries - 08/23/2005
Hi Crew,
<Hi, Sam!>
I have a 10 gallon SW 2 years old and fairly stable for about a year with a clown goby, 2 spotted cardinals and mushrooms, 2 candy corals, snails and 3 hermits.  I removed about half of a clump of Chaetomorpha and in the piece that remained I noticed some tiny fuzz balls.  I though it was moldy food caught in there. But on closer inspection they all have mouths. I suppose they are squirts of some sort.  
<That or sponges.  I've had some nifty neon green sponges show up in my Chaeto from time to time.>
I also have some white stuff on the glass. They are small blotches, pearly white in color, paper thin and growing very slowly.  It only comes off with a razor. Could it be a kind of coralline algae?
<Very likely.>
or? Finding new things is half the fun.
<You are so, so correct.  Learning new things is the best part of life!>
I do not understand why people get so upset when they find things they do not expect.
<I could not agree with you more!  Thank you very much for this....  I wish everyone everywhere showed this same zest for life....  Wishing you and your new discoveries well,  -Sabrina>
 

Dot ID 8/21/05 Hello.  I am wondering if you can identify this new thing that has popped up in my aquarium? I will post a link to the picture from my photobucket account.  They are small white dots with hair like legs all the way around them.  I circled them in red.  I'm sorry that the picture isn't that good, but they are the size of a pinhead.  There are about 100 of these all over the glass. It is a 75 gallon saltwater aquarium with 110 pounds of live rock.  All levels are perfect. Thank you very much for your help. Jeff Goering <Very likely some sort of micro-crustacean... e.g. copepod most likely... not harmful... Bob Fenner>

Mystery Creature or Menacing Microalgae? 8/9/05
Hi guys,
<Scott F. your guy today!>
I have something that I think is algae (could be a fungus, I don't know).....I can't get a good pic to attach because of the size, and I  haven't been able to find any pics, or even text descriptions that match what I'm seeing...
<I'd LOVE to have a pic of these things...>
This stuff appears as small white ovoid stalks that have a 'furry'
exterior and a small tuft on the end...the largest stalk is about 3/4" long...
<Man, this could be anything from some sort of algae to a Bryozoan or even a Tunicate. Do look up these creatures on the 'net and see if you can find something that approximates what you're looking at.>
The first one that I noticed was growing out of the base of a dead coral that I didn't remove (even dead, it looked nice; never ID'd it, but it was a hard branching coral, light-green in color with fluorescent blue circles/spots on it, it that matters).  Since then, they are popping up all over the place...on the glass, power heads, filter tube, etc...with the exception of the (now dead) coral, it seems that it is only sprouting on non-organic surfaces...
<Interesting observation, but perhaps coincidental..>
Is this an algae?  It's becoming a problem as it is spreading
everywhere...I'd like to know what it is and if you have any
recommendations for natural-control methods....
<I really need a pic to make a confident ID.>
I have a well-established 75gal tank with 2 powerheads, protein skimmer and Emperor filter; live-sand substrate and ~50lbs of live rock...I can follow-up with anything else you may want or need to know... Thank, in advance, for you assistance....
Eric
<Well, Eric- I think the best aid will be a pic or two of these things. Otherwise, I'm really just taking a wild guess. See if you can get one to us and we'll do our best to get a positive ID! Regards, Scott F.>

Seeing Spots - 08/07/2005
Hello there!  
<Ahoy, matey!>
I have recently discovered your site and find it very informative.   
<Ahh, good.  Glad to hear it.>
About 2 weeks ago I noticed a spec on the glass.  
<.... I know where this is going already....>
I went to wipe it off thinking that it was a drip of water and found that it was actually on the inside of the tank.  As I looked at the spot, I could see that it was moving.  It was very tiny.  It was white/clear with a yellow dot in the center and what appears to be a split tail.  Its head became very large as it moved along the glass.  It then disappeared into the sand.  A few days later I saw two of them on the glass.  
<These may possibly be an Amphiscolops sp. flatworm; harmless.  See here:  http://www.wetwebmedia.com/flatworms.htm .  Otherwise, harmless amphipods or copepods are likely.>
Then I did not see them at all until today.  I found 4 of them about 1/8 to 1/4 inch in length.  They were moving between the glass and the sand.  As I was watching them, I noticed VERY time white spots all over my glass.  Upon close inspection they all appear to be moving.  Apparently these things are breeding.  What I do not know is what they are.  I am fairly concerned because there appear to be so many of them now.  I am hoping that you may know what these are and how I should go about ridding my tank of them.
<Most or all (likely all) are absolutely harmless, and very welcome, creatures.  Do not rid your tank of them.>
I have an approx. 90 gal reef tank that was started about six months ago with approx. 100 lbs of live rock and 80 pounds of sand (half live/half dry),
<The rock (and possibly also the sand) is the source of these very desirable animals.  Consider these hitchhikers as free food and janitorial service.>
two Eclipse 3 hoods with full spectrum lighting, an AquaC Remora skimmer, and a blower bar.  My current inhabitants are:  1 Maroon clown, 1 Bird Wrasse, 1 BTA, 1 Flowerpot, 5 green striped mushrooms, 1 Tube Anemone, 2 Flame Scallops, 1 Sand Star, 2 snails, and a half-dozen or so hermit crabs.   
<Do please start reading up right away on the lighting needs of your BTA and the (lack of) longevity of the flame scallops....  also the substrate needs of tube anemones....  much to learn, here.>
I have been performing water changes about every 2-3 days to keep the nitrates down.  Is there anything else I can do aside from water changes to keep the nitrates down?  
<Make sure your skimmer is running well and properly, and consider adding a refugium or at least add some sort of macroalgae (I like Chaetomorpha, personally) to the system.  You might want to look into using reverse osmosis and/or deionized water, as well.  You can also research the denitrifying benefits of a deep sand bed (usually 4" or more of oolitic aragonite sand).  Much on all these topics and more in the Marine section: http://www.wetwebmedia.com/marine/index.htm .>
My nitrates went from 0 to 40 as the tank began maturing.  Originally I was performing water changes about once a week.  Once my nitrates reached 40, I upped the changes to 2-3 times per week.  My nitrates have now dropped to about 15, but I am still hoping for 0.  I performed an approx. 20% water change yesterday.  Temp is constant at 80, Specific Gravity is 1.025.  My tank after testing is:  pH, 8.4; Ammonia, 0; Nitrite, 0; Nitrate, 15; Calcium, 360 - added two capfuls of Kent Marine Liquid Calcium and have not yet retested; Phosphate, 0.
<Dare I suggest it....  Sneak out at night, well after lights-off in your tank, with a dim flashlight with red cellophane over the light.  Peek in the tank, and I almost guarantee you'll be amazed, delighted, disturbed, and excited all at once at the things you'll find in your tank after dark.  A very few may be harmful, but 98% of things that could potentially come in on live rock are pretty good critters, and HUGE fun to research - start discovering the new animals in your home, and I'll wager you'll never stop!>
Thank you, Felicia Las Vegas, Nevada
<Wishing you and your system well,  -Sabrina>

Fish Waste 8/4/05
Hi Crew,
    I was wondering if there are any invertebrates that you know of that consume the waste that fishes produce?
<Mmm, ultimately? Many filter feeders... Please read here:
http://www.wetwebmedia.com/marine/index.htm
Bob Fenner>

Invert questions 8/4/05
Hello Wetwebmedia Crew, <Hello, Steph>
I'm so glad I found your site, it's very informative! <Thank you>
I have several questions regarding invertebrates and
other ‘things’. I'm a newbie so please bear with me.
Also keep in I'm in the middle of cycling my tank.
1. I think I have a Christmas tree worm - it's fairly
big and lives in a rock I bought from my fish store.
It looks just like a Spirobranchus giganteus Pallas,
Horned Christmas Tree.  I can't feed it b/c I’m
cycling my tank - what should I do? is it going to
die??  <They are a little harder to keep then most feathered worms.  Wouldn't hurt to put a few drops of invert food in there, preferably, spot feed it.>
2. I have weird grey matter on one particular rock
that has all this short grass on it. It just
started showing up. I wonder if the grass is dying or
if there's something bad growing on it - is the grey
stuff anything I should be concerned with?  <Too soon to tell, see if it survives the cycle.  Would need a pic to identify.>
3. There are a couple 1" long worms that are half red
and half black with lots of legs and little bristles.
are these worms harmless? I hope it's harmless, it’s
cute. <Sounds like the dreaded bristle worms which can harms other inverts and fish if they get large enough.  Might want to invest in a bristle worm trap.>
I’m sorry if my questions are very ‘newbie’. I look up
my questions in forums, but sometimes it’s very
difficult to find the right answers.<Try the WWM FAQ's, etc, just type in the key word such as "bristle worms" and you will have several choices.  Reading is the best thing you can do right now.> The main thing I
want to know is if all this life is going make it
twice as long to cycle the tank. My nitrite level is
at 4.0 and my ammonia level is at .25. I feel badly I
can't feed them since I'm waiting for my levels to
zero out. Thank you for your time, I look forward to
hearing from you when you get the chance! <Feeding "them" shouldn't hurt the cycling process, just feed sparingly.  Good luck in your newfound hobby.  James (Salty Dog)>
Steph

Strange Worms 8/3/05
Hi Crew, I'm hoping you could ID some creatures in my marine tank? (although I appreciate that without a picture this may not be very easy.) I have a 30G marine aquarium with approx 10lbs live rock (more being added gradually). The stats are as follows:
3 x 30 watt fluorescent tubes (2 x daylight plus  1 x actinic blue moon)
3 small powerheads placed strategically for optimum water circulation.
1 x Fluval 104 MSF external filter.
Ammonia - 0.  
Nitrite - 0.
Nitrate - 15ppm.
Calcium - 380ppm.
pH - 8.1
Phosphate - 1ppm. (I know this is very high, I'm working on getting it lower.)
<All here sounds good, but beware that each time you add live rock, that new piece has to cycle.  It is much easier to get this all over with up front.  Also, elimination of the external filter may help eliminate your nitrates.>
Inhabitants are:
1 x Red legged hermit
1 x Cleaner shrimp
2 x Turbo snails
2 x unidentified "hitchhiker" crabs (one tiny and one approx 1" across)
1 x small colony of yellow parazoanthid polyps.
<This all sounds fine, but crabs are generally risky.  I would strongly consider trapping and removing them.  This is usually easy to do by baiting a glass with some weighted meaty food and leaning the glass against the rockwork at a steep angle.  The crabs will fall in seeking the food, but won't be able to climb the smooth sides of the glass.>
Many pods and bristle worms and many feather dusters. There is also a large bunch of Chaetomorpha in the tank. This leads me to my question - There appear to be lots of small wormy strands that are smooth at one end and get bristly at the other end.
They are cream/white in colour and at first I thought that they were dead strands of Chaetomorpha as they appear to be dead plant matter. But on closer inspection, they appear to be alive. They are attached to rocks and some of them are attached to the Chaeto, they move around in the current but also appear to move independently from the current retracting and stretching and sometimes look like they are trying to catch pods (they appear to be permanently anchored to whatever they are attached to). Also, when my cleaner shrimp was innocently walking around one of the rocks he suddenly jumped backwards quicker than I realized he could move! I think he may have been stung by one of them (he seems fine now). They are approx 1 or 2mm thick and range from 1cm to 6 or 7 cm when fully stretched. What do you think they could be and are they harmful to me or my pets? Thanks for any advice or help you can offer, you are always most
helpful. Leif, Birmingham, UK. <There are a few critters that fit your description.  The most likely is a type of tube worm that usually inhabits sand, which it uses to construct it's tube, they can also inhabit other substrates.  Another possibility is ctenophores.  These are stationary relatives of jellyfish that resemble long this strings of flags.  Both of these critters are generally smaller than what you describe, but could fit the bill.  Both are harmless.  Stinging possibilities include hydroids and Aiptasia, but these seem unlikely.  Sorry not to be more helpful, but a picture really is worth a thousand words here.  Best Regards.  AdamC>

Unknown organisms 7/27/05
I have a 10 gallon SW 2 years old and stable for about a year with a clown goby, 2 spotted cardinals and mushrooms, snails and hermits. There always seems to be something new that starts growing and eventually cycles out. Right now I have lots of
circles on my glass and shells, even on the snails. They look like a white thread  rolled up in a circle and a few hairs
sticking out of the end. Some are barely visible and others are up to 1/8 inch across. I remember reading about these on this site but right now can not seem to find it. <There are several kinds of worms and snails that form spiral calcareous tubes.  All are harmless.  Without a picture, it is hard to guess, but I am quite sure there is nothing to worry about.>
They come off glass fairly easy with a razor blade but what can you do about the ones on the snails? <I would leave them be, but if it really bothers you, you could clean the snails in a bucket of salt water with a scrub brush.>
I also have something that looks like a purple blob (1/4 inch or less) with a pipe sticking up and sometimes a hair sticks out the pipe. What is it?  So far only have a few.  <This one is even harder to guess, but it is probably a sponge or sea squirt.  Another harmless visitor to enjoy!  Best Regards.  AdamC.>

Mysterious disappearances 7/19/05
all of the sudden fish and inverts are disappearing in my tank.  two small firefish and, two peppermint shrimps and now a small Coral beauty.  I don't understand it.  My Oce Clownfish, larger Sally Lightfoot, and my Banded Coral Shrimp are OK.  Is it a mantis Shrimp..  The fish and shrimps seem to be doing well but then just disappear.  No carcass or anything found.  I have looked at night and found nothing unusual..  Corals are fine as well.
Help!!!
Mark
<Dude! Fix your spelling, grammar... and read on WWM re. Bob Fenner>

Worms - 07/19/05
Sorry to bother you.
<<No bother>>
I usually find what I'm looking for on your site, but
I'm not entirely certain this time.
<<ok>>
I have a 45 gallon reef tank (teeming with live rock, mushrooms, polyps, frogspawn, feather dusters, 7 shrimp (1 pistol hitchhiker), porcelain crabs, snails and 6 fish (yellow tang, pink
Pseudochromis, blue damsel, false percula, brown barred goby, jeweled rock skipper).  Yes, I know, probably over-populated.
<<Yes...please consider finding another home for the tang...>>>>
The wet-dry is for a 75 gal. tank, the protein skimmer is good and there are several powerheads in the tank for circulation.  I clean the tank and protein skimmer, change the filter pad and perform a 13 gallon water change weekly and the water quality is fine.  
<<Very good!  I love to see people doing "weekly" maintenance.>>
Everything in the tank is thriving and I'm not over-feeding.  However, the last time I added a button polyp, within a few
days what appeared to be intestines (white, curly, gross) appeared in several spots, on the polyp itself and on the wall of the tank.
<<Possibly mesenterial filaments (digestive organs) from a defense response as a result of stress.>>
Within a day or so, they disappeared.
<<Yep>>
Then I noticed tiny little clear shrimp-y looking things on the filter pad when I change it, and several long, thin, white worm-y
looking things in the bottom of the wet-dry.  I haven't seen any of these things in the tank itself, however, but it seems that there are more of them each week in the filter.
<<Probably amphipods and bristle worms, beneficial detritus feeders...  Though you haven't seen them they are in your tank (came from/live in and around your live rock, and as you are discovering, will also accumulate in your filters.>>
I'm wondering if I should be concerned or not..
<<Don't worry...be happy... (do I hear music?)>>  
I'm also curious as to where they came from - are they hitchhikers?
<<Yes...hitchhikers from the live rock.>>
Thanks.
Emily
<<Regards, Eric R.>>

Floating specs 7/18/05
Hello WWM crew, couple weeks ago I had an ich problem with my fish in my 45
gallon tank. So I removed them into a 30 gallon and treated with copper that
went perfect. But I took the filter off my 45 gallon and put it on the 30 for
now; I have no corals or anything like that at the moment. I have a protein
skimmer, but I just thought I'd add some more water flow; I don't have a power
head yet. So I added a bubble stone device onto an air pump, worked nice for
awhile.
<Quite an interesting sentence structure for now with the copper...>
Then I decided to spend the night at one of my friends house, came home and I
noticed several floating things. They appear to be like maybe a spec of sand
or sugar, something in that region floating in the water with a tiny white
tail. They are shaped sort of like a raindrop or something, the spec thing on the
bottom, tail up. I also looked very close and observed that every now and
then they kind of move in direction, usually upwards. Also, the motion is in one
swift action. I also noticed somehow the air device which was responsible to
much of the water flow had somehow got out of the tank, leaving very little
water flow.
<Neat>
There are hundreds of these floating specs with white tail spec things
floating. Could you please tell me what these things are?
<Likely some sort of crustacean... or possibly a worm. Not harmful... will go on their own. Bob Fenner>

USO (Unidentified Swimming Object) 7/18/05
Hi, I have discovered an un-identifiable critter in my still cycling 75gal FOWLR tank, it's going on it's 4th week, and its doing great, 3" of crushed coral, 15lb maybe 18 lbs of liverock for now, intend to put more in later.
<So much life comes in on live rock, it's mind-boggling. Course, I suppose it's not so great should you find a Eunice worm or pair of Pyramidellids, but...>
I've noticed this small star fish looking critter up behind the powerhead, it's small about the size of a quarter,( if it's arms were all stretched out ),  it's brown in color, has six arms, has a kind of pattern of white stripes on it's arms, sort of resembles a small star fish, only this thing has a distinct open/looking center shaped like a snowflake, so after reading about starfish, I have my doubts this is a starfish as most of them have 5 legs/arms, I would be interested in finding out what this thing is and should I be worried about it. Sorry I tried to get a picture of it with my camera only I could not get a decent enough of a picture to send ya.   Thanks in advance
<In most identification cases, identification attempts are futile without a photograph, but the creature you have described is a fairly common, well known, and easily identified one. You merely have an Asterina species starfish. They commonly have multiple arms, as they can split themselves in two to reproduce. Though I have heard reports of them eating coralline algae, one would need a decent-sized population to have any real impact in a tank of 75 gallons. They will serve as helpful scavengers, cleaning up detritus, as well as interesting showpieces, for when they do decide to show themselves.
Here are a few links related to Asterina stars:
http://www.wetwebmedia.com/asterinafaqs.htm
http://www.wetwebmedia.com/ca/cav1i4/echinoderms/echinoderms.htm
http://www.wetwebmedia.com/seastars.htm
http://www.wetwebmedia.com/echinode.htm
http://ctd.mdibl.org/voc.go?voc=taxon&browser=r&termUI=7593
Hope this helps, and best of luck with your new tank! Mike G>