Please visit our Sponsors

FAQs about Crustaceans 2

Related FAQs: Crustaceans 1, Crustaceans 3, Crustacean Identification, Crustacean Selection, Crustacean Behavior, Crustacean Compatibility, Crustacean Systems, Crustacean Feeding, Crustacean Disease, Crustacean Reproduction, Micro-Crustaceans, Amphipods, Copepods, Mysids, Brine ShrimpHermit Crabs, Shrimps, Cleaner Shrimps, Banded Coral Shrimp, Mantis Shrimp, Anemone Eating ShrimpHorseshoe Crabs

Related Articles: CrustaceansMicro-Crustaceans, Amphipods, Copepods, Mysids, Isopods, Shrimps, Coral Banded Shrimp, Cleaner ShrimpP. holthuisi Pix, Mantis "Shrimp", Lobsters, Slipper Lobsters, Hermit Crabs, Squat Lobsters, Crabs, Arthropods, Pycnogonids (Sea Spiders),

Reef safe? Maybe when small. A Mithrax sculptus... not by algae alone...

Shrimp and Crabs.... Can't Keep Them Alive To whom it may concern: I have a 55 gal. salt tank with live rock, feather dusters, 2 black finned clowns, 2 bar gobies,1 fire Goby, 1 green mandarin, 3 candy striped gobies, 1 palette tang, 1 African flame back angel and 1 cleaner wrasse.  I have no problems with the fish I have had all of them from several months to a 1 1/2 years. <good to hear> The problem I am having is trying to introduce any kind of snail, shrimp or crab.  I have tried acclimating them in several ways, adding a little water over 45 min..<I would test your water for copper> I put them in the tank and they either die immediately or within an hour or so.<huh, doesn't sound good, are these shrimp and crabs healthy when you purchase them?> I just did a 20% water change 3 days ago.  My ph was a little low but everything else is where it should be. Could you tell me if there is something I should be looking for in my water tests that would keep me from being able to keep shrimp, snails or crabs in my tank.<check your water for copper> I have a wet/dry filtration system, 3 powerheads, a protein skimmer that I faithfully maintain.<ok> Any help would be appreciated. <The only 2 things I can think of is there could be copper in your water, or you are getting livestock that aren't healthy, Good Luck, IanB>

Mid Course Correction (Making Adjustments To An Existing Tank) I started my first saltwater tank shortly after Christmas. It is a 55 gallon Wal-Mart special. I am running two 20-30 gallon hang on the back filters I had from some old freshwater tanks. I have about 2 inches of sand. <Do consider going to 3 inches plus, or reducing to 1/2 inch or less...2 inches is a biological "no man's land", too shallow for complete denitrification, yet too deep to be fully aerobic...> I have never tested anything other than the specific gravity of the water. It has always tested a little high, but all creatures seemed to be thriving, especially the algae. <Understandable. It's quite possible that you have a buildup of nutrients, such as nitrate and phosphate, which may be contributing to the algae problems. This is where water testing for these compounds is helpful> I have to clean the glass every two weeks. I have: 1 Red Scarlet Hermit Crab 10 Dwarf Blue Leg Hermit Crabs 1 Emerald Mithrax Crab (Now Deceased) 1 Sand Sifting Starfish 1 Dwarf Snail  (Hitchhiked when I bought Blue Legs) 1 Chromium Fish 5# Fiji live rock 5# Bali live rock (New) 1 Molly Miller Blenny (New) 1 Nemo (New) Percula Clownfish <Hah, Hah...Nemo...> Everything is doing great, with the exception of the dead Crab. It was doing fine until a little over a month ago. It's shell started turning white and I noticed it seemed to be trying to scratch or pull it's shell of with it's pincers. I figured it was trying to molt. The white slowly and continuously got worse. I figure when it died today it was 75% covered in white. I never noticed any abnormalities in it's behavior. I also am not aware of how long it should take them to molt. I called and talked to a technician at Drs. Foster & Smith and they said to start checking the Iodine and Calcium levels and adding as needed. <I was thinking along the same lines...Rather than supplement, though, you may find out that regular small water changes will help provide the "supplementation" that your system needs> When the crab died I had not yet been able to get to a store to buy test kits, iodine, and calcium, therefore I do not know what levels they are currently at. Those items will be next on my list of purchases for my tank though, because the Emerald Crab was one of my favorite creatures thus far and I plan to replace it. I searched and read about sometimes these animals will die when trying to molt. With all this in mind do you feel the crab died while trying to molt, or more likely something else caused it do die? Also, if it died while molting would it have probably died on its own, or did I cause it to die by not checking the iodine and calcium? Also, I would appreciate any other advice you may have. <Well, it's tough to say...But I think that it's a possibility that the crab died as a result of water chemistry issues, or perhaps, even a predator...hard to say. Those water tests will be illuminating, for sure!> I have never tested Nitrates and Nitrites due to fact I have been told in my situation they should be alright. I use tap water and add Chlor- out. I also used live sand and sand together. <Well, tap water has a lot of undesirables in it which can contribute to a number of problems in closed systems...Consider utilizing RO/DI or another purified source> Thanks for your time, MH <Well, you may want to pick up a copy of "The New Marine Aquarium" by Michael Paletta, or Anthony's "Book of Coral Propagation"...Both will give you a bunch of solid information that can help you correct a few things and get your system running in top form! Good Luck! Regards, Scott F>

- Mystery Clicks - Hi I have a two foot salt water tank. It is stocked with the following: 1 Clown Fish 1 Coral Banded Shrimp 1 Dottyback 1 Blue Tang Some live rock There has been a clicking noise (on occasion) coming out of my tank for some time now (around 5 months). I am not sure what it is, but I have been told that it could be a Mantis Shrimp - which is supposedly something that can smash the glass of the tank. <I think a bit extreme for most mantis shrimp...> I have read your FAQ and info pages on the Mantis Shrimp and I found it quite informative however I just wanted to ask the following: 1) I cant find this Shrimp so is it possible that any of my other stock can click? I have been told that Clown fish do some clicking. The clicking sounds like a coin tapping against the class. <Probably not the clown fish. What is more likely is that you have an Alpheid, known by several common names - clicking shrimp, snapping shrimp, or pistol shrimp. Many of these come in very small sizes - less than an inch, and keep well out of site. The only way you know they are there is from the clicking at all hours.> 2) I have noticed a worm like creature on a live rock... it looks like a worm and I couldn't really see a head... it was very quick. I was about to stick a net in and try to catch it, but as soon as I touched the glass it went off like a bullet into the live rock. <Hmm... could still be a mantis shrimp... they can move very quickly.> If this is the culprit then it is possible for me to take this bit of rock out. I only managed to see it at 4:00am one night while I had a hangover. I haven't managed to see anything in normal spectator hours :) I don't know if it is possible to set a trap for it? Because my coral banded shrimp is pretty quick - he will go for any bait lying on the ground. <Mantis shrimp can be trapped.> 3) If it is a mantis shrimp - my concern is that it could crack my tank??? <Probably not unless it is huge.> Is that a true concern? <Not for most, and even then only with the smashers.> Another important concern is my fish - but so far no incidents. <As far as your fish go, they are in more jeopardy from spearing mantis shrimp, and these you wouldn't hear clicking. Smashers typically go after snails and small crustaceans. Look for the mysterious loss of snails, crabs, etc.> 4) Also, another thing that happened the other day (off the topic) - My Coral Banded Shrimp (Lenny) shed his shell. he has done this a few times now.. It is quite an impressive process. Anyway it seems as though one of his legs (or arms) is a bit weak or injured. Is it possible that he could have shed prematurely or something went wrong? <Many things can go wrong during shedding, including the loss of life and limb - it's a rather precarious time to be a shrimp. Typically the lost limbs will grow back after successive molts.> He hasn't really been himself. A bit reserved. <Perhaps just tired after the molt.> The Dottyback and blue tang are a new addition and he was going after them a bit. Is it possible that he shed because of these new additions? <Possible, but not so probable. What might be more likely is... well I'll just ask straight out, how much iodine do you put in your tank. Additions of iodine seem to cause shrimp to molt... so if you've been dosing iodine, you might want to cut that amount in half, or better yet test for it before you add.> Your help is much appreciated. Regards Simon <Cheers, J -- >

CRITTER ID <we need more info about behavior, texture, size, feeding habits, etc.. A pic would really be easiest and may be the only way to ID for sure. Best regards, Anthony Please help me ID these critters I've found in my 55 gallon marine setup.  I have about 45 pounds of live Tonga rock.  been going for about 3 months.  a few days ago I noticed these 'guys'.  they range in size from pepper grain to 'rice' length.  They live within the rock and only come out ultra quickly (speed of lightning) and return to their hole.  They seem to be gathering sand grains or pushing out sand grains or eating smaller creatures to small to see.  It happens so fast I can't really tell what they're doing.  However,  I can tell you they all have 2 yellow body sections.  Somewhere around the head is a yellow band and around the mid-body area is another yellow band.   The rest of the body seems to be clear.  I've seen maybe 10 of them.  I'm thinking the actual population in my tank could be multiplied by a hundred or a thousand as far as I know.  It may be impossible to get a picture.  I was shocked when I first noticed one, because I was watching a 'different' creature calmly walking along a rock (possible copepod or amphipod) and this mystery creature shoots out and snatched him up, and returned to his den all in like 1/10th of a second.  But then he must have released him because a second or two later the 'copepod' popped back in the same spot seemingly unharmed and made no attempt to escape.  It was as if this mystery creature was playing around or practicing.   Oh crew of great wetness!! your wisdom is precious! Micah----fellow reefer..man..

Fading Crab? Hello - <Hi there! Scott F. with you today!> I was hoping you could provide me with some info. I have had a Emerald Green/Mithrax crab for about a year. It is a beautiful shiny green. It looks like it has been waxed. Over the past month or so it has started losing its color and fading away to a whitish gray color. Do you know what would cause this? Could it be a deficiency of some sort? I was thinking it was molting but it has been like this for several weeks now and keeps fading more. Could it be undernourished? Thanks for any help you can provide. Have a nice weekend. Dennis   <Well, it's really hard to say...I think that, if the crab is provided with an appropriate diet, including lots of algae, then it could be anything from water conditions (proper iodine levels- maybe) to calcium buildup on the shell...lots and lots of possibilities...Just keep providing the animal with lots of good food and it should live a long healthy life. Regards, Scott F> - Question on Reef Babies - Hi I just recently looked in my tank and saw thousands of very tiny babies with one tail that flicks that where just born have any idea which one of the animals below was likely to have them? <They are most likely copepods and/or amphipods, zooplankton that likely came in with your live rock.> horse shoe crab1 sea star1 hermits 20(blue legged and 5 that are stripped like zebras) snails Astreas 10 decorator crab the one I think could of had them even though I have one pencil urchin1 tang highly unlikely right yellowtail damsel unlikely that's all and the babies are free swimming there all over my serpent star so it may have been it but I didn't see any eggs they probably would have got eaten please write back ASAP thanks JM <No worries. Cheers, J -- >

- Follow-up on Reef Babies - I found who had the babies it was the Decorator crab I watched her release the last of the babies out of a kind of pouch under her belly. Weird I think they carry them kinda like seahorse until the eggs hatch and release is this the first decorator birth? Thanks JM <First one I've heard of... Cheers, J -- >

Mole Crabs Hey guys! I have only found one reference to this critter on your website, so I thought I would ask the question: I live in Mobile, AL near the Gulf of Mexico. We frequent the beach and find "sand fleas" or you may know them as "mole crabs". They are white and about the size of a mans thumbnail. They don't/can't bite or pinch. They burrow into the sand and live on sand in the breaking waves. What do you know about them? <Superfamily Hippoidea, likely genus Emerita... you can read about them a bit here: http://www.wetwebmedia.com/marine/inverts/arthropoda/crabs/swcrabs.htm or use your search engines for more> I think they would do a fine job of "stirring up" the sand bed in my refugium. Do you think they'd add value to the system? <Mmm, actually quite difficult to keep in captivity... as their habitat involves incoming/outgoing wave action...> Another question if you don't mind. Since I have access to a natural beach, how can I benefit from this access. Is there any benefit from using natural seawater over "ready-mix" blends? <Please read here... actually, see you're continuing to ask general questions that are answered on our root web: WetWebMedia.com Please go there and use either the indices or search tool on the home page> How about using natural sand or sifting through the sand to gather copepods? It seems like there would be something very useful to my reef aquarium to add to the bio-diversity. Thanks, Jeff McHenry <Keep studying. Bob Fenner>

Who You Calling Shrimp?  3/22/02 The little shrimp was a little under an inch, and only a few mm wide.  He was running in and our of a Hermit Crab shell.<Is the hermit in the shell?> By pod did you mean copepod or amphipod?<Ya>  Its not one of those guys (I'm pretty sure its some type of shrimp)<Gosh, It doesn't sound like anything I've ever seen.  You've posted on the forums so maybe someone there has seen something like it!  Good luck!  Phil>

What? No Crab Legs? Hi crew, my tank is 90 gal live rock setup. and I have been having problems with Mithrax and an arrow crab's dying, the arrow crab began losing its leg's so I checked the water parameters all ok. ammonia 0 nitrites 0 nitrates near 0. everything else is absolutely fine in the tank hermits shrimps etc., any help would be welcomed. Gary <Hard to say what's causing this, Gary. It could be a deficiency of iodine, which assists the creatures with molting and exoskeleton formation and growth. I'd test for iodine levels, however, before I would add any on an additional basis. You also need to keep a very stable environment, which it sounds like you're doing. Finally, make sure that these animals are getting enough nutrition from the foods that you are providing. Good luck with this situation. Regards, Scott F>

Barnacles >Have enjoyed your web site and found it very informative and helpful. >>Excellent, glad to hear it.   >We have a 75 gal tank and have been increasing the amount of live rock, we're at 93 lbs.  The last piece we purchased has barnacles on it.  Should we keep it or dispose of it.  From what little I have been able to find on them they can be harmful to the fish population.  Help!  Ceil Wagaman  >>I do hope you've been following proper curing and q/t protocol, yes, even with live rock.  Yes, some barnacle species are actually parasites of fish during larval stages.  If it were my bit of rock, I'd set up a small, dedicated system with sufficient circulation, just to watch the critters.  However, if they're attached to a very large piece of rock and you can't separate them without harming them, then yes, you would be prudent to remove them.  Marina

Re: Barnacles >Hi Marina, >>Hello again Ceil. >Thanks for your quick reply.   >>More than welcome. >It is a fairly large piece of rock and has many barnacles on it.  To remove them I was thinking of just scraping them with a knife. Would that do the job or could you suggest a better way, or just remove the rock completely?   >>Boy, that's a tough one.  I like hammers!  Just kidding.  If a knife or some such works to remove them, then I see no reason not to go this route. >The salt water person at our local supplier thought it was a great piece, but after reading the short piece in Mr. Fenner's book became very concerned and looked for more expert advice. Also I am looking for some books on proper marine aquarium procedures and maintenance.  I have Robert Fenner's "Conscientious Marine Aquarist", It is a good light reference but I would like something more detailed. >>I am a huge fan of Julian Sprung, Martin Moe, Jr. (his marine aquarium handbook is essential in my book!), C.W. Emmens, John Tullock, Anthony Calfo (especially in regards to reef invertebrates) are all good authors to look for. >Would also like to purchase a more complete book on marine fish species (characteristics, habitate, what the good and bad points) are for future reference in adding stock to our tank, a book on inverts as well.  I would like to start to build a library of reference material. >>FANTASTIC!  Too many folks don't give due credit to the usefulness of having a good reference library on hand.  Unfortunately, in regards to more publications like "Conscientious Aquarist" and what Bob has done in identifying and classifying species by suitability, I know of no other book that quite does what he's done there.  Maybe you can pose a query on the talk forum of wetwebmedia--> http://www.wetwebfotos.com/talk >>I'm positive that there will be plenty more suggestions on good books to have in your library there. >Thanks so much for your help.  I want to do things right and enjoy the hobby at the same time.  Ceil Wagaman >>You are so very welcome, Ceil.  You have warmed the cockles of my heart!  Our goal is to ensure that folks succeed (and spread a little love along the way, maybe).  Marina

Smart tunicates and hairy crabs 3/21/03 Good evening, I hope you guys are doing great and still learning cool things.  I'm the girl with a bi-color blenny, Japanese wrasse, canary blenny, and  new addition of a zebra blenny (both of which are fat and healthy on their special diet of live brine shrimp).  My Nerites are also happy and breeding much faster than rabbits. ;]   I went snorkeling out on Key Biscayne today, it was great.  Its not Bonaire, but nice nonetheless.  Last time I collected some tiny bright orange colonial tunicates (not glass tunicates) on a blade of turtle grass.  Then  I glued them to an under ledge on my rock.   <interesting> Well, I've always thought that they're very interesting creatures?, since they have a spinal column and all. <sort of> But did you know they're pretty smart too?!   <do tell> When I looked at them today there seemed to be less of them (maybe the hermit crabs got munchy), but when I took a really good look later I noticed that they had actually moved!!  In a matter of days half of the colony has moved onto my LR and off of the grass blade.  I had no idea they could do this, especially since they're colonial. Super cool!  Well, that's my bedtime story, just thought I'd share.  ;] <very cool... there are a handful of motile species... and among them, most do not move that quickly. Maybe yours recently ate spicy food> By the way, when I collected some stuff today a very small hairy (most likely decorator) crab hitchhiked with some stuff.  I like to save any creature that accidentally comes with LR or during collection, but I'm afraid that when this crab gets big it won't be reef safe.  Your advise? <unsafe almost certainly in time if not now. Most crabs are opportunistic predators> After a fair bit of research the other day we did decide to save a tiny pistol shrimp (one cm) that came with some frag rock.  He's in our show tank and won't really harm much even when it gets bigger (hopefully not really big) since this is a temporary tank.  Are most pistol shrimp fairly reef safe if the tank is well fed? <agreed> We do flake, plankton, brine shrimp, pellets, etc (mind you not all in the same day) ;]  Nitrates at 0 I swear!  Well good night!   Love, Morgan <its all good... thanks kindly for sharing my friend. Anthony>

Let's Play... Name That Shrimp!   3/19/03 Hey again Phil!<What up?> Yeah, I could go reef with those lights.  :)  <Now your talking!  :)  > Now that the water is back to its normal parameters, it should be safe to add another fish, right?<Ya, I'm kind "Mr. Safe" and I would wait a few more days.  2 or 3 at the most.> Also - on another good note we found a hitchhiker - some little shrimp.  I haven't seen any pictures like it so far, and it doesn't look like a mantis shrimp (thank god).  I have no clue how he came in, but it was still a neat find.  He's had to have been in there for at least a month.   The little guy looks like a shrimp, and one arm is a lot bigger than another. The top part of his shell was dark brown, and the bottom kinda yellowish. Any ideas on what he is?  (I know that's a bogus description, but I haven't been able to get a pic with the camera yet)<Can you tell me the size?  If it's really small it could be some sort of pod.  I'll do more checking and will get back with you.  Hope this helps!  Phil>

- Mystery Critters - I have a salt water tank, in it are 12 blue leg hermit crabs, 3 emerald crabs, 1 urchin, 2 clown fish, and a rather large hammer polyp. I just noticed little white things crawling all over the tank glass... Little like the point of a pin. Any ideas what they are? <Sound like copepods and/or amphipods.> And how should I get rid of them. <I wouldn't - they're a sign of good things going on in your tank.> Thanks <Cheers, J -- >

What's that noise??? (Pistol/Mantis shrimps) Hi, I am 5 weeks into my first (properly set up) saltwater aquarium.  It's 55 gallons, I have 60 lb. of live rock and about 4 inches of live sand.  I have about 15 blue legged hermits now and 20 turbo snails.  I have evicted 2 stone crabs and a strange looking hairy legged hermit (returned to the LFS). At 3 1/2 weeks I added a peppermint shrimp, and a week later, after several daily water testing that came out negative for nitrate and ammonia, I added a diamond goby.  Needless to say, I don't see my two critters much.  The shrimp seems to hide in the rock as far as I can tell, and I see raised areas (maybe burrows) in the sand in which I suspect the goby hangs out.  I don't remember when it started, but it seems like about the time I added the goby I heard popping or clicking noises from the aquarium in the middle of the night.  I flew out of the bed to make sure nothing was trying to escape from the aquarium, and I couldn't see a thing that could be making the noise.  It doesn't sound like it's coming from my powerheads or my skimmer. It almost sounds like it's coming from around the LR.  I searched online and read about pistol shrimp.  Could I have one that hitchhiked on the LR?<yes> There isn't any way it's the peppermint shrimp making the noise, is there?<no> My best guess has been a hitchhiker pistol that is enjoying the new friend (my goby) and suddenly became more active. <Most likely, could be a mantis shrimp as well. Try to observe at night under dim/red light to identify. If you decide you don't want it, many ideas for trapping here: http://www.wetwebmedia.com/marine/inverts/arthropoda/stomapods/mantisshrimp.htm and beyond> Thanks for your help! <Happy shrimp hunting, nothing like sneaking up on a tank in wee hours to observe critters! Don>

Re: What's that noise??? (Alpheids) Hi, I am 5 weeks into my first (properly set up) saltwater aquarium.  It's 55 gallons, I have 60 lb. of live rock and about 4 inches of live sand.  I have about 15 blue legged hermits now and 20 turbo snails.  I have evicted 2 stone crabs and a strange looking hairy legged hermit (returned to the LFS). At 3 1/2 weeks I added a peppermint shrimp, and a week later, after several daily water testing that came out negative for nitrate and ammonia, I added a diamond goby.  Needless to say, I don't see my two critters much.  The shrimp seems to hide in the rock as far as I can tell, and I see raised areas (maybe burrows) in the sand in which I suspect the goby hangs out.  I don't remember when it started, but it seems like about the time I added the goby I heard popping or clicking noises from the aquarium in the middle of the night.  I flew out of the bed to make sure nothing was trying to escape from the aquarium, and I couldn't see a thing that could be making the noise.  It doesn't sound like it's coming from my powerheads or my skimmer. It almost sounds like it's coming from around the LR.  I searched online and read about pistol shrimp.  Could I have one that hitchhiked on the LR? There isn't any way it's the peppermint shrimp making the noise, is there? My best guess has been a hitchhiker pistol that is enjoying the new friend (my goby) and suddenly became more active. Thanks for your help! <Likely what you're hearing is a/some hitchhiking (as on/in your live rock) alpheid or pistol shrimp. Please see here re: http://www.wetwebmedia.com/marine/inverts/arthropoda/shrimp/shrimp.htm and the FAQs beyond (in blue, at top) re these shrimps. Bob Fenner>

In A Crabby Mood! Background: 95lbs live rock 90 gallon tank temp: 77f salinity: 1.022/23 2" live sand bottom (ya, I know... it should be 3+) 2 Percula Clowns 1 Pearlscale Butterfly Prawn Goby Fire Goby Coral Banded Shrimp Cleaner Shrimp Pistol Shrimp 1 small green emerald crab 1 larger red emerald crab 1 black brittle star 25+ blue legged hermits 20 snails Questions: >1.  Perhaps these tie together??  I purchased about 6lbs of liverock around Christmas time... it has fully cured.  It looks as though there was some sort of sponge on it originally which has now become just a hardened whitish crust with some small holes in it.  Now that it's been in my tank, the whitish crusty sponge matter is now turning green and purple with algae...  My water tests have all been fine over the past three weeks with it in my tank, is this something to be worried about?? <Frankly, I'd only worry if there is noticeable organic accumulation, or measurable water quality declines. Just keep an eye on the sponge, and your water chemistry...> 2. Haven't seen my small green emerald crab since about Christmas time...prior to that, I hadn't seen him for weeks.  Is he good at hiding, or do you think he may have perished? <Wow- impossible to answer that one! I've seen these guys vanish for a few weeks, only to reappear none the worse for wear later. Just keep lookin out for him> 3. My larger red emerald crab (he's about twice as big as my small green one) has turned from a nice orangey color to fairly pale over the past 2.5 months...  I haven't seen him in about 4 days (not too worried about that), but should his color change concern me?  He's eating all the time...  I don't know what could be wrong with him... if anything. <Frankly, there may not be anything wrong with this crab. I think that it may be a simple color change as a result of his surroundings...It also might be a result of diet...I would not be overly concerned, as long as the animal appears otherwise healthy> I can see perhaps my Pistol Shrimp possibly having the small green emerald for dinner... but I don't think he would touch my red emerald.  I've witnessed the Pistol Shrimp firing off his 'pistol' right behind the red emerald crab... I've even seen him snap at the crab... but the crab is too big for him and doesn't seem to even notice the Pistol Shrimp's aggression.  My Pistol Shrimp has acquired a taste for my small blue legged crabs of note... Any advice???   <Well, the pistol shrimp is certainly a prime suspect...I'd keep a close eye on him> Could this spongy stuff on my rock be hazardous for my crab to eat??? <Hard to say...Some sponges do indeed contain substances that may be toxic to animals that dine on them. Again, I would not be overly concerned... Just keep observing your tank carefully, maintain good husbandry techniques, and you should be fine! Good luck! Regards, Scott F>

Re: S. cyanoscellus vs. E. daumi (marine crustaceans) Hello, I have some questions concerning marine crustaceans: First some background:  I have a Stenopus cyanoscellus.  He was in a 65 G fish only and then in a 29 G mini-reef.  Has been doing well for about 1 year.  For almost that entire time he had a Enoplometopus daumi tankmate.    They got along fine in the 65 G but when I moved them to a mini-reef (too treat the fish only tank) the lobster lasted a few weeks and then died.  He appeared to have been pulled apart limb by limb.  I blamed this on a Pseudochromis who is now gone. <Mmm, more likely the Stenopid>   But I recently placed another E. daumi in the reef tank and now I have found him with several limbs removed and not looking too good.  In addition to the shrimp, I have a pygmy angel, a neon goby, and another small goby sp. (sold as rusty goby) in the tank. First question: Have you heard of boxer shrimp beating up/killing reef lobsters? <Yes>   The shrimp is smaller and must less bulky than the lobster. Second question: If the lobster survives, I will move him back into my 65 G fish only tank (which would have been a better place to begin with, I guess).   But I had hoped to keep some pistol shrimp/goby pairs in that tank.  Will the lobster have problems with the pistol shrimp?  What about with a decorator crab? <Much less likely than with the boxing shrimp> Third question: Now that I think back, I have had many camel and peppermint shrimp disappear over the last 5-6 months in my mini-reef.  The common denominator remains  the S. cyanoscellus.  I knew they would fight among themselves, but do they kill other shrimp as well? <Definitely yes. The most commonly utilized species, Stenopus hispidus is or should be notorious for these mortalities> I appreciate your advice. Thanks, Steve Thornton MD <Bob Fenner>

The Creature In The Cave (Mantis Shrimp?) Hello all at the WetWebMedia crew. <Scott F. here today!> I have a quick question. Today I bought some new (cured) live rock and when I got it home I found some stowaways on it. The usual couple of small snails and other little things. But I saw something that appeared to be some sort of crab like thing. I don't really know what it is cuz I haven't seen it come out all the way. Its got its own little cave its hiding in. What I have seen is its got some hairy legs and a pretty good sized pincher and its purplish red. I don't know if this would be a Mantis Shrimp of some sort. Or some kind of crab. I know the description is a little vague, but its all I've seen. Thanx. <Yep- impossible to tell from here. If you are concerned (and it certainly is worthwhile to be concerned), I'd try "baiting" the creature out of it's cave with a little meaty food, such as minced clam, squid, etc. Maybe you can get  better look and make a positive ID. If it's a mantis, you'll have to decide what you want to do with it, and then go from there! Good luck!                                                                              Matt

My Tank Is Ticking <Greetings, JasonC ducking for cover...> Just kidding, thought I would get your attention quicker if you thought you had an opportunity to make a few Bomb jokes... <Ahh yes, you are a comedian ;-) >  Sorry, I no longer have the email that you sent a month ago...  You had mentioned that a Feather Duster might be a nice addition for my fish/invert tank. 90 gallons 95lbs of liverock about 2" of live sand {I know, I should have 3"+ and will do so when I move in a year} 2 Percula Clowns 1 Pearlscale Butterfly 1 Shrimp Goby 1 Fire Goby 1 Coral Banded Shrimp 1 Red/White Cleaner Shrimp 1 Pistol Shrimp 1 larger red Emerald Crab (one dead or alive but really good hiding small green emerald) 1 dead or hiding black spiny Brittle Star 20 Blue-Legged Hermits 15-20 Snails Of note, I am also waiting for a Royal Gramma to add to my tank in the next couple of weeks. 1.  Based on my livestock, I was wanting to tryout something colorful and interesting and you had suggested the Feather Duster as it is not light dependant. <Feather duster bets are off with that Butterfly in the tank.> I have fairly basic lighting... certainly nothing that would support corals...  So, based on my livestock... just to confirm/refresh our memories...  Feather Duster would be ok??? <I wouldn't chance it.>  One of the more experienced guys at Big Al's -in my opinion- said that my Butterfly might very well eat it. <And I would agree with him.> Oh, and if I was to get a Feather Duster... do I just put him in my tank?  Do I have to position him where I want him? <Yes, they can't move on their own.> What would be the process for introducing a Feather Duster... could not find any info on your site. <Acclimatize like any other invertebrate.> 2.  In another email, it was mentioned that Brittle Stars need lots of liverock and livesand.  If I had just two Brittle Stars in my tank, would 95lbs of liverock be enough? <Yes. Brittle stars are very successful scavengers... they'll do just fine.> 3.  I like my Pistol Shrimp, but my hermits have dwindled to approx 20 from 45 in 3 months.  As well, you had suggested that the possible disappearance of my small Green Emerald crab and my Brittle Star may be the cause of my Pistol.  Big Al's has a marine pest control trap... is this something that should be used? <I thought you said you like your pistol shrimp?> Any risk of trapping CBS or Cleaner??? <Of course there is. Hermit crabs are overrated anyway, let them dwindle and replace them with some Nassarius snails.> 4.  I have read conflicting information and wanted your opinion.  Some info I have read suggests Blue-Legged Hermits will kill snails for their shells and that Red-Legged Hermits or Scarlets won't? <Have seen both do this.> My guess is that both of them would?? <And you would be right.> General crab question... if I was to add a few Halloween crabs to see if they survive the wrath of my Pistol Shrimp... would these crabs fight with Hermits or Emerald? <Hermit crabs will likely duel with anything that has a shell, just to see if the shoe fits. I think any/all of those would become food for the Alpheid at some point.> 5.  Snails...   I have read that some snails can't 'right' themselves if they fall on their back and will die.  Fact or fiction? <Or perhaps Darwin in action - natural selection.> Is there any concern in having a few Turbos, a few bumblebees, etc??? <A concern? I don't think so, not with that snapping shrimp in there.> Does different snail species in a tank pose any problems? <No.> My guess is no, but then again... "what do I know" <Apparently enough to get most of your own questions correct.> Dave <Cheers, J -- > P.S.  I love the sense of humor you guys have... my favorite...  someone wrote in "My tank is ticking..."  I think you were thinking the same thing I was... BOMB!!!! or Pistol....   hehe... <Huzah!>

Starfish breeding, barnacles swimming How do star fish mate? and if a barnacle attaches to a whale would it be a benthos or a free swimmer? please reply <Please see here re the seastar reproduction: http://www.wetwebmedia.com/seastars.htm and barnacle larvae that settle on whales are planktonic (not capable of locomotion beyond the currents, and adults not ever benthos (stuck on the bottom). Bob Fenner>

- What is It? - <Hello, JasonC here...> Hi again guys, and I hope that you all have a Merry Christmas and a very Happy New Year. <And you as well.> Thanks for all the good work and advice that you've given.  Santa brought me the CMA for Christmas and I'm already way into the book and I have already learned a bunch.  Now, on to my questions.  First, I noticed some little "jumpy-crawly" critters that look like the "Rollie-Pollie" bugs that you would see when you lift up a rock outside. They are crawling around in my substrate (crushed coral). The exception is that they are whitish-clear, looks like they have lots of legs and are fairly small in size.  And there are many.  I'm going to assume they are harmless and will eventually become fish food.  <A good assumption. They are most likely copepods and amphipods which are basically "sea-bugs" - a good sign of a healthy and active system.> Just wanted to hear from you guru's that they are indeed harmless.  Second, I've noticed on my live rock there are dark green "bubble-ball like" things attached to it in a few different spots. <Most likely a pest algae named Valonia.> They too are fairly small, in some places one bubble-ball, and in other places maybe 2 or 3 together.  Any ideas??? <You can read up more on this here: http://www.wetwebmedia.com/greenalg.htm > Thanks again for answering our questions and helping us all to be better "reefers." <You are quite welcome.> Maureen
<Cheers, J -- >

Re: Pods? (Steven) Howdy again! <Hi Cathy!> Thanks Steven, for the challenge of trying to get a good picture of a squirmy, wiggly "bug"! <Oh, but you are a professional.> Trying to get a clear shot....anyway, I've attached a few jpeg's to this email. Let me know if they come through? <Unfortunately, I cannot open a zip file.> This is my black bug, pics #3 & 4 came out the best. I included the first one so that you can see the black, the others are with the 'pod in a dish so you can see him. If I need to send one at a time, I can do that ;-) <That would be great!> If you can see the pics, let me know what this critter is? <Once I see it, I will certainly try.> Looks like a 'pod of some sort, but I have never seen a BLACK one. <My neither. You may just get yourself a photo credit in our new book.> THANK YOU! From sunny Texas... -Cathy <>< <You are welcome from gross, cloudy Pittsburgh. -Steven Pro>

Pods! Dear Bob and Crew: <Scott F. here this afternoon!> While changing my water today I found about 9 or 10 curled up live larvae or shrimpish looking things.  They swim by stretching out.  My husband thinks they look like shrimp. <Well, you'll be happy to know that you have a population of amphipods! These are harmless creatures, that essentially function like scavengers, and as an added benefit- many fish love to eat 'em!> I have a 60 gallon salt water tank and was also cleaning the substrate in the rear of the tank - a place which is not cleaned too often. <That's a perfect 'pod environment. In fact, many hobbyists set up refugia and other systems just to cultivate these creatures. Fish like mandarins, some wrasses, and many others, relish these creatures as a supplement to their diets.> My tank also has live rock, crabs and snails.  This is the first time I have seen these critters - are they good or bad - should I put them back into the tank or throw them out?  Right now I have them in limbo. Thanks for a quick response due to this life or death situation for whatever they are. Connie Cavan <They are harmless, so I'd simply put them back into the system. They should be just fine in there! Good luck, Connie! Regards, Scott>

Pods! (Pt. 2) Dear Scott: Thank you so much for replying so quickly.  You have made me and my fish very happy! Connie Cavan <Glad to help! Take Care!>

QT & Compatibility for Crustaceans + Hello. I have my 10 gallon QT all set up and running. Mr. Pro wrote back below, "You could house Cleaner Shrimp with Scarlet Reef Hermit Crabs or Blue Legged Hermit Crabs". I was about to do that, but then I saw what appears to be very small growth of that Aiptasia on my LR. So, after reading the FAQs, I figured I would go with the Peppermint Shrimp. <Ok> Finally my question, will the Peppermint be okay with the crabs mentioned by Mr. Pro, or are there different crabs I could get (or none)? <The Peppermint shrimp will be ok with the hermit crabs. The big question to you is, do you even what the hermits in the first place. Please see the archived information regarding on www.WetWebMedia.com> Also, I just received my Methylene Blue in the mail. Do I dip the shrimp and crabs, acclimate them right into QT or what? <You cannot freshwater dip any crustaceans. You might as well throw them into a pot of boiling water and eat them. Just acclimate them to the QT tank using a very slow drip acclimation, also outline on www.WetWebMedia.com.> Thanks again for making my venture less fearful. Rich <Good luck to you! -Steven Pro>

QT & Compatibility for Crustaceans + Bob: <Steven Pro, part of the question answering crew for www.WetWebMedia.com, here today.> I am converting a 10 gal freshwater tank to a QT tank. It has been dry for about a year. It was only rinsed out when I took it down. How much cleaning will it need? Do I still need to use bleach or whatever the website says about cleaning? <I would first clean with bleach (one cup of bleach to five gallons water) to remove and old algae marks and then use vinegar (same dosage as per bleach, one cup to five gallons) to remove any hard water marks.> Also, my first candidate will be a crustacean or two. Maybe a shrimp or crab thing. I read in your book, The CMA, where it says shrimps, crabs, lobsters will eventually find each other and...:(. So, I really cannot have a cleaner shrimp and 2 herbivorous crabs together? <It depends on the crabs. You could house Cleaner Shrimp with Scarlet Reef Hermit Crabs or Blue Legged Hermit Crabs, for example.> Anyway, I read a lot about keeping QT tank minimal, but is there anything special I should put in there for these characters? <The PVC pipe sections mentioned here http://www.wetwebmedia.com/quaranti.htm will work just fine. I would also read through the linked FAQ files for additional tips.> Lastly, do I have to monitor Ammonia as much as daily and change water constantly for them like I have read about fish? <This depends on how well your quarantine tank filters have been seeded/cycled.> Thanks, Rich PS: I now understand how people send such large emails; I started out with one question until I started typing. <This was nothing compared to others. -Steven Pro>

Cleaner shrimp and crab not surviving in my tank Hi Craig, <Hi Jun!> It's me again. I purchased a cleaner shrimp and a sally light foot crab today (third or fourth cleaner shrimp and the second light foot crab in the last 6 weeks). Within several hours they're already dead. What am I doing wrong? Water parameters are all good. I followed the acclimation process and still no luck. Please help!!!!!!! Thanks.....Jun <Hmm, did you purchase these from a local fish store or have them shipped? If shipped, this could be from adding a normal pH water to a waste laden shipping bag, perhaps affecting the toxic ammonia levels.  Also, these guys are incredibly sensitive to salinity changes. If there is a big difference in salinity it needs to changed very, very slowly, like over a day or so. A drip line works well for this and changes water very slowly. These guys are sensitive! I sure hope this helps you. Craig> 

Re: cleaner shrimp and crab not surviving in my tank Hi Craig, <Hi Jun, How goes it?> Thanks you for the prompt response. I might try it again probably 1 more time. I found the dead shrimp this morning but no sight of the crab (he might still be alive).  <Very possible> Another question if that's OK with you. Is it alright to place leather corals (toadstool and colt coral) side by side?  <Yes, but do give them room, they can both put on some healthy growth, the colts tend to be more aggressive and some require more current, so be mindful of their individual requirements. You can find more on these corals and their placement by searching on their common names "Toadstool leather" or Sarcophyton and "Colt coral" or Alcyonium on WetWebMedia.com. Just give them room to grow.> Where can I find (WWM) regarding coral placement? Thanks again....Keep up the good job (of helping people like me with this challenging but rewarding hobby)....Jun <Enjoy! Craig>

Identification question--Barnacle Bill These little creatures (one of them, not the grouping) are about the size of my little fingernail... photos taken at Edisto Beach in South Carolina about 3 weeks ago. Can you tell me what they are? <yes my friend... barnacles. Do I win a hairy Kewpie doll now :)?> Thanks, Muddy
<cloudy but still standing, Anthony>
identification question These little creatures (one of them, not the grouping) are about the size of my little fingernail... photos taken at Edisto Beach in South Carolina about 3 weeks ago. Can you tell me what they are? <Barnacles... likely Lepas anatifera, the Smooth Goose-Neck Barnacle. Bob Fenner> Thanks,

Acropora "mites" AKA 'Red Amphipods" I have a 10 gallon nano with some small SPS frags and I have notices small orange mites crawling around on a couple of the Acropora frags.  <ahhh, yes... not uncommon at all. A curious little arthropod. AKA "red Amphipods"> They look like little fleas. They are very small but viewable to the naked eye. What can be done?  <some say they are parasitic, but I and most aquarists do not believe this to be true. No proof yet. At best they flourish incidentally while SPS corals wane/die from other common denominators (water quality, lack of QT, etc)> Is there a safe dip or treatment I could give?  <some have employed FW dips... I do not believe this is necessary> Are these parasitic or commensal?  <the jury is still out... leaning towards commensal> I have searched and found no information on these.  <do a keyword search on reefcentral.com and other large message boards for perspective (use "Red Acropora Mites", "Red Amphipods", etc.) to get a consensus. My advice is to simply watch carefully and do employ a natural predator if possible (Red Sea pseudochromid, small wrasse, etc)> Thank you ahead of time for any help. <best regards, Anthony>

QT & Compatibility for Crustaceans + Thank you for you fast reply. To follow up: what will my shrimps/crabs eat while quarantined 2-4 weeks without substrate, etc. <Just about anything you can get to them; flake food, pellets, sinking wafers, and bits of frozen foods (krill, plankton, formula foods, etc.). -Steven Pro>

Lowest salinity safe for crab and shrimp? Hello again. I apologize for so many questions, there is so much to learn. I have read over all the FAQ's regarding lowering specific gravity for reduction of ich. I am leaving my tank for 2 months without fish hosts to greatly reduce parasites. <After two months, there will be no more parasites. They will all perish in one month.> There is a Lysmata cleaner shrimp and a white spotted hermit crab in there with live rock, my question is what is the absolute lowest I can reduce salinity to without killing my crustaceans? <No need to do the low salinity with no fishes, but anyhow, I would not go below 1.018.> Right now I have it at 1.019 with a temperature 84. <I would leave as is.> Regarding my 2 quarantine tanks one with a maroon clown and neon goby and one with purple tang and neon goby what is the lowest salinity possible these fish will tolerate? <I have read of treatments as low as 1.010.> If my maroon clown shows no signs of parasites and seems very healthy can I please take out the CopperSafe, it has only been in for 7 days, but she has been visibly parasite free for 6 days. <I would run the suggested course of treatment.> I know she is sensitive to copper and I want to take it out as soon as is safe to do so and put in a piece of live rock to hopefully help with reestablishing bacteria after the copper. <There are other treatment options in you do not like copper; daily water changes and freshwater dips are my two favorites.> Also is it okay to take copper out of purple tang's tank after 2 weeks even if she still has faded spots/scars on her body. <Same advise as above> Thanks again for all the wonderful help and advice, I would be so lost without your website. No one at any of my LFS can ever agree or seem sufficiently knowledgeable to trust. ~Kylee Peterson <That is a shame. -Steven Pro>

Mole crabs hi, I'm doing a research project on mole crabs, and I need to know their phylum. <Arthropoda... the jointed legged animals, along with insects, bugs, fleas... more defined: Crustaceans... Please see here: http://www.wetwebmedia.com/marine/inverts/arthropoda/crustace.htm Bob Fenner> do you think that you could help me? I haven't been able to find it anywhere. Thank you, Kathryn

Artemia Hi, Bob, Antoine, Steven, and the rest of you (sorry I cant recall your names :( ) I have 2 damsel fish & I'm planning to feed them with Artemia (just to give some diverse food, and not just flakes) I bought Artemia eggs and tried to hatch the Artemia but after 3 days nothing comes out. Reading in different sites I saw that is better if I decapsulate the eggs previously, but I couldn't find the method to do it, so... can you give me some advices (or CONSEJOS in Spanish!!) one more... can I use daphnia to feed sea fish? Saludos amigos! Carlos Hello Carlos! Craig here.... Artemia, or Brine shrimp, are great for encouraging reluctant feeders to eat, but in terms of nutrition they are more like whipped air. You can soak the hatch in Selcon before feeding which will increase the nutritive value. The hatch should be close to the same with whole eggs if you have the proper temperature, aeration and light. It's best to hatch what you will use within 12 hours for the most nutritive value.  A better replacement would be Mysid Shrimp which are higher in nutritive value. For more info on Brine shrimp, Daphnia and feeding fish, try: http://www.wetwebmedia.com/AqBizSubWebIndex/bizfoods.htm Good luck! Craig

Lots 'O Bugs! Hi Bob or associates. I'm presently half way through a 6 week marine fish\ display tank separation brought on by entrenched ich. I've noticed with no fish present that a lot of very small life seems to be blossoming.  <Makes sense, no? Less predation (well, different), movement, resource use altogether...> Maybe I'm just trying to find something to watch in a seemingly empty tank. <Yes! Always the subjective domain to consider> Seriously, I've noticed clusters of dots "dancing" in front of holes in my coral and shells. I'm pretty certain these are Copepods.  <Perhaps... or Mysids... or one of many other possibilities> Lately, I've noticed a very small shrimp-like creature with a flaring tail, egg-cluster or belly, and two black eyes. It's about 3/16 of an inch long. It hangs in mid water, until it suddenly jerks backwards. This morning there were at least a hundred of them clustered against the tank's background. Any idea what these are? I guess the obvious question would be;: Are they harmful? <Not harmful (unless you're a small competitor, potential prey item. Some sort of crustacean, likely one of the thousands of species of copepods... look on the Net here, for keys to groups, species. Bob Fenner> Thanks for any enlightenment you can give me. W. Tripp

Red / purple bugs Hi guys = ) <cheers> I noticed yesterday that there are teeny tiny reddish purplish bugs on the front glass of my tank. Everything is doing fine, and the bugs only seem to be on the glass. You can hardly tell they are bugs, they look almost like specs of algae, but when you look really close, they are moving. Can you please advise me in any way possible as to what these little bugs may be, and give me some advice on what to do to get rid of them or direct me to a website to help me out. Thanks Marci <hmmm... I'm not certain what they are just yet. Most common amphipods and copepods are opaque/clear/white. Some flatworms are reddish colored... do you think this critter you have is more like a flatworm/"Planaria" rather than a crustacean? Does it have visible legs? It is likely harmless but I agree that we do want to ID this critter. Any chance of a close up digital picture? Kindly, Anthony>

Re: red / purple bugs Hello again = ) <cheers> We have attached some pictures of these teeny reddish purple bugs that we sent a question about yesterday.  <yes, thank you> They don't look like worms,  <agreed... they are crustaceous: AKA "Red Amphipods"> but maybe they help you identify them and give us an idea of what to do about them and if they are good or bad for the corals and / or fish. Thanks for you help. Marci and Mark <there is much controversy over these critters... some believe them to be parasitic on SPS corals and for many folks they seem to be quite harmless. I have my doubts that they are predatory. If you have any concerns, the point may be moot with a small six-line wrasse, Pseudochromis, etc to prey on them. Many natural predators on such tasty plankton. Dragonets too. Best regards, Anthony>

Re: red / purple bugs Hello again = ) <Howdy> We have attached some pictures of these teeny reddish purple bugs that we sent a question about yesterday. They don't look like worms, but maybe they help you identify them and give us an idea of what to do about them and if they are good or bad for the corals and / or fish. Thanks for you help. <These are larval forms of crustaceans... likely copepods (copepodites)... and not a problem... more a sign of a healthy system than deleterious. Bob Fenner> Marci and Mark
Re: Parasite (not) I thank you so very much for your quick and informative reply. We feel much better knowing that this probably wont kill her. (15 minutes from when I first sent my question to receiving your reply) Now that is fast. <Your photos were definitive... the "classical shape, eye-spot... Wish I had a plankton tow of small critters to show you. Bob Fenner> Stephanie

Become a Sponsor Features:
Daily FAQs FW Daily FAQs SW Pix of the Day FW Pix of the Day New On WWM
Helpful Links Hobbyist Forum Calendars Admin Index Cover Images
Featured Sponsors: