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FAQs on Freshwater Crustaceans: Clam, Seed Shrimp, Ostracods

Related  Articles: Forget Crawfish Pie, Let's Make a Crawfish Tank! By Gage Harford, Freshwater to Brackish Crabs by Bob Fenner, Terrestrial Hermit CrabsInvertebrates for Freshwater Aquariums by Neale Monks,

Related FAQs:  FW Crustaceans 1FW Crustaceans 2, FW Crustaceans 3, & & FAQs on: FW Crustacean Identification, FW Crustacean Behavior, FW Crustacean Compatibility, FW Crustacean Selection, FW Crustacean Systems, FW Crustacean Feeding, FW Crustacean Disease, FW Crustacean Reproduction & Small Freshwater Crustaceans Groups, by Genus: Triops, the Amphipods Which Are Gammarus (Scuds), Daphnia (Water Fleas), Cyclops, & Crustacean Selection, Crustacean Behavior, Crustacean Compatibility, Crustacean Systems, Crustacean Feeding, Crustacean Disease, Crustacean Reproduction, Freshwater Shrimp, FW Crabs, Terrestrial Hermit Crabs, & Marine Hermit ID, Hermit Behavior, Hermit Compatibility, Hermit Selection, Hermit Systems, Hermit Feeding, Hermit Reproduction, Hermit Disease/Health, & Crayfish FAQs, Crayfish 2, Crayfish ID, Crayfish Behavior, Crayfish Compatibility, Crayfish Selection, Crayfish Systems, Crayfish Feeding, Crayfish Disease, Crayfish Reproduction,

Re: football shaped creatures I bought some live plants for my freshwater aquarium at the pet store some time ago. Some other stuff must have come along because pretty soon I had some snails. I also got hundreds of little "bugs". These things are barely visible. They scoot around in the tank. Under a microscope they look like little footballs. Their bodies open up like a clamshell and little hairs come out of the opening and propel them around in the water. <<Not sure exactly what they'd be but they are most likely harmless. I've heard of similar creatures in other tanks, most of the time they seem to go away on their own after a bit. You might use the Google search box at www.wetwebmedia.com to see if you can find anything similar. It is a good idea to fully quarantine any new plants just as you would new fish to prevent these types of things and also diseases from getting into your system.>> The only thing in my aquarium is a little African frog and some of the snails. The frog is fine, but the snails keep dying. I don't know if the little bug thingies are responsible for the high snail mortality rate, or if it's something else. Any ideas???? Russ <<I doubt these are causing the death of the snails. FW snails multiply very rapidly and I'm sure there is a lot more die-off than most people generally notice just because there are usually fish and other distractions in the tank. I wouldn't worry too much about it unless it is causing problems in your ammonia/nitrite levels. Ronni>>

Re: football shaped creatures After a little more research I discovered that these things must be some kind if ostracod. <Yes! Nice pic!> They look like this except their shape is more like a football. Supposedly they eat algae. I couldn't find anything that said they were harmful to snails. <No, they (ostracod crustaceans) aren't> So these little guys seem to be thriving but even though I change over 50% of the water every two weeks my snails keep dying?? <I would check the difference between your new and old water and store and match their characteristics before using. Please see here: http://www.wetwebmedia.com/water4maruse.htm Bob Fenner>

Ostracod Anomaly - 08/05/2005 Hey, thanks for a great and informative site. <Glad you enjoy it!> I just have a problem with Ostracods in my tank, they just appeared out of no where and it doesn't seem like there's a solution to this problem. <I recall when I was quite young, I had a small tank with renegade snails, and had the same problem.> Is there a way to get rid of these with out harming my plants and shrimps? <Reduce their food source - vacuum substrate heavily to get decaying materials out, feed significantly less, remove dead plant leaves if any, and perhaps try to find a fish that will make a meal out of 'em.  I've used Gourami to control aphid populations on floating plants; possibly dwarf or pygmy Gourami would consider Ostracods edible....?> Thanks, John <Wishing you well,  -Sabrina>

Ostracod Anomaly - II - 08/07/2005 I actually don't know what is causing it, its not the food source, I only feed my shrimps a little 2 times a week. Thanks. <I wonder if perhaps they are feeding on plants or decaying plant material, or possibly algae....  Again, it might be worthwhile to employ a small predatory fish in this system and see if that controls the population.  Wishing you well,  -Sabrina>

Re: Ostracods? Dear Bob: <BD> Thanks for your reply. I am hoping to experience first hand the effects of bioluminescence from Ostracods <Mmm, I recently saw a citation re just this...> - preferably dried. Would your kit labeled "Ostracods 100+ organisms" be the best bet? I realize these are living organisms? <I think so and yes> Are there any problems with customs when shipping to Canada? How long is lead time and delivery? <I'd ask the folks sending...> Thanks, Blake P.S. I assume this is your company? <Mmm, nope... we don't sell anything... but maybe the books we produce. Bob Fenner>

Tiny invaders in freshwater aquarium.   2/20/07 Hello! I cleaned my daughter's aquarium recently and was about to dump the dirty water when I noticed tiny, reddish-brown specks moving by themselves.  I put some of the tiny organisms under the microscope and took the attached pictures. <Neat!>   I wonder if you have any idea what they are.  This is a ten gallon freshwater aquarium with five tetras, a Pleco, a Cory cat and two freshwater shrimp. <Looks like an Ostracod... Clam shrimp, sometimes called "water fleas", though they're not fleas... Crustaceans... harmless... actually even beneficial... Help to keep the tank "cleaned up". See the Net re this name. Bob Fenner>

"Bugs" in fresh water aquarium   2/3/07 I recently added an African Dwarf Frog to my aquarium. Unfortunately it died 2 days later. I also have a snail and 3 red minor tetras. About a week after the frog died I noticed these "bugs" in the tank, they are all over, probably a few hundred. They are about half the size of a pin head. They like to attach to my snail. they form a mucus puff under the snail foot and seem to be under the foot inside the shell. The fish store had no clue what they are and sold me some medication for parasites and it did nothing. <Mmm, not parasites... very likely some species of crustaceans... can/do "come in" with other life...> I had a co worker in our Lab look at them under a microscope. They look flea like but have a shell like a beetle with brown/black and white stripes. <Neat... maybe a Cladoceran... Ostracod> They move fast and multiply quickly. I added salt to the aquarium the other night and it did seem to knock them out a bit, but I would like to totally get rid of them. Any clue as to what I have? We are all stumped. <See the above term in your search tools... Many possibilities, but highly likely these are not dangerous... and will "pass" on their own... with the unfolding (evolution) of this system... time going by. Bob Fenner>

Crazily mis- over-stocked FW sys.... w/ induced prob.s... Crazy! Oh, and HH ID    7/23/09
I was wondering if you could help me out with my Freshwater tank problem.
<Am trying>
I have a 90 Gallon tank. which is home to 3 Aruwans, 3 Oscars, 2 Silver dollars, 1 clown knife fish and a Giant Pink Gaurami.
<Yeeikes! Way too crowded... and only going to get worse... All this, these animals won't live well or long in this small volume>
The tank has 1 External Filter , and two submerged filters, 2 air supply pumps. Gravel Substrate and two tank ornaments.
The water temperature is at a steady 78 deg and changed 25% every two weeks.
<I'd change this amount weekly>
About a week ago I've noticed a lot of tiny white bubble like creatures in the tank, very similar to tiny fish eggs. Now they seem to be moving around the tank and sometimes cling on to my Oscars. Yesterday my clown knife fish died unexpectedly ( No symptoms of being sick or hurt).
<Stress alone...>
These white creatures are now all over the gravel and some on the sides of my tank as well.(Photo attached)
can any one tell me 1).What are they? 2) How can i get rid of them?
<Small crustaceans of some sort... Perhaps Cladocerans... not harmful... Best to "be rid of them" by simple vacuuming, cleaning of the gravel... BUT, you need NOW to move, separate the life you list... READ re the needs of these species. They can't all live in a ninety. Bob Fenner>
Any help would be greatly appreciated.
Thank you

Re: mis- over-stocked FW induced prob.s   07/23/09
Thank you Bob Fenner for your advice I will try it.
<Ah, good>
Hopefully I will be able to write back "problem solved" Also I have just setup another tank so will be moving the Oscars out soon.
Thank you once again.
Vishwas Shetty
<Welcome my friend. BobF> 

Bugs in the water  4/29/08
As my friend looked into my tank tonight she asked me what was in the tank. I told her it was just water junk because I had pulled the filter cartridge out for an ick treatment. I was wrong. There are a whole bunch of small bugs at the bottom of the tank. We have not added anything into the tank recently. I had emailed your website a while back with questions about some problems we had with our mollies. It was suggested to change the water and to use a section of a hose to siphon it out, because we were low on money and couldn't buy one. We happened to have a hose we were going to get rid of and cut a section of it out to use. I would imagine these bugs came from the house and are quite happy living in our tank. I don't have a clue if the fish are being affected or what they are. They are a very very light tan color. The only thing i can describe them as is a round little bug. It appears as if there are quite a few of them now. I would love and advice on what to do! Thank you!! -Tara <Mmm... need a better description... likely this/these are either aquatic insects or some sort of crustacean. Might be harmless, might not be. Bob Fenner>
Re: bugs in water  4/30/08 I was able to get some decent photos of the tiny little bugs in our tank. I also took a video of the tank and you can see them swimming around. <Neat... do have a rather definitive type of locomotion...> They seem to stay near the bottom of the tank and crawl on the rocks more than swimming. I hope the video but I am not able to attach it to this email, if you would like to view it let me know and I'll try to post it online somewhere. <Try You-Tube...> I cropped the pictures to reduce their size and show only the bugs. Thank you!-Tara Tara Hendricks <This/these are very likely Ostracods... Seed Shrimp... harmless, and quite interesting. Bob Fenner>

Re: bugs in water, FW Ostracods, video  5/1/08 I haven't been able to see them close enough to see how they are moving. It almost looks like they glide across the rocks and when they do swim in the water, I can't tell how. I got the video uploaded. It isn't that great, trying to capture tiny things, in water, through glass, isn't too easy. They are the small dots that kind of randomly appear. I'd find one that was moving and it would be gone before I knew it. Sorry I was moving a lot, I was trying to find a spot where they were most active. You definitely can't see them up close but you can see them in the water a few times. http://www.youtube.com/watch?v=Edq-K70Etdc Tara Hendricks <Makes one appreciate the "nature shows" doing such work eh?! Thank you, BobF>

There is something living in my Betta's tank  8/4/07 I have a Betta (over a year old). When doing a partial water change a few weeks ago I noticed very small black specks floating on the surface. Last night when feed my Betta I saw these little specks moving about on his rock and on the gravel below. There must be hundreds of them. I removed the Betta from his tank as a precaution. The local fish store doesn't know what these specks are. The fish seems fine, just a little irritated at getting moved out of his home. The tank has gravel, a plastic rock to hide in and a plant that grew from a bulb. Any ideas as to who the new neighbors are and should I be concerned about them? Thank you for you help. <Mmm, well... could be a number of types of life... worms, crustaceans of sorts... but not likely deleterious/harmful. A photo (micro) graph or loupe examination will likely get you to the phyla level in ID. You could bleach/destroy these (see WWM re), but I would likely ignore them. Bob Fenner>

Re: There is something living in my Betta's tank  8/5/07 Hi, <Hello again> Thanks for getting back to me. This morning I had to take our 4 legged pet to our vet, and while I was there I asked if she could put one of the little critters under a microscope and see what these specks looked like. She had not seen them before but they appear to be an oval crustacean. A first, it was just a brown/tan oval covered with hairs/cilia. When we continued to look, it would open up very quickly like a bi-valve or clam. <Ah, very likely an Ostracod... aka seed shrimp... See Google images re> Maybe it uses this action for movement, like a scallop?? We came to a similar conclusion as you, that it was harmless. Perhaps they have been in the tank along time, but with the warmer temps, their population exploded and they became obvious. Meanwhile, "Cosmo Bubbles Wong" has been returned to his freshly cleaned tank, and is once again happy. Thank you for your help, You know us fish mom's, we worry over everything. Susan <A pleasure to assist you. Bob Fenner>

Re: There is something living in my Betta's tank  8/6/07 Yep, it's an Ostracod! Fascinating little creatures. Thanks again. <Ahh! What a planet eh? Thank you! BobF>

Need some direction (FW, possible unwanted cladoceran) 2/25/09 Neale? <Yes...?> I'm perplexed and need some direction and encouragement. I have a 20 gallon FW tank stocked w/ a dwarf Pleco and 10 glass fish. All but one of the glass fish was just added a couple weeks ago. Current water parameters are: 78 degrees, 0 ammonia, 0 nitrite and ~ 20 nitrate (I know. more frequent water changes) and above 7.8 ph due to municipal water supply. <Sounds good.> All was good until I noticed during a water change last week that small white specks would enter my gravel vacuum during vacuuming. They purposely returned to the gravel. I initially thought they were just non-living specks from who knows where, but then looked more closely and they appeared to be swimming freely in the water - darting here and there, really. If they were located on the fins of my stock, I'd definitely treat for ich. But they aren't. Interestingly enough, I noticed this only one day after adding frozen brine shrimp to vary the glass fish diet. All the fish appeared fine, so I dismissed it (.mistake). <Harmless. Have them in some of my tanks.> NOW they are taking over the tank - there have to be thousands of them. Again, they are free floating. NOT on the inside of the glass. From your site, I'm assuming they are cladoceran (aka water fleas). If so, Bob Jenner says they will run their course in time. But the glass fish are absolutely miserable with them, as they cannot relax and just hang out. They dart all over, nipping at one another constantly. Another interesting development is that my Pleco is out of his cave during the day more in the last week than I ever remember him - very odd. And when looking closely at the fish tonight, it appears that the white specks are now attaching themselves to the glass fish, mostly at the tips of the top/lower fins. So I started treating w/ ICH tonight w/ a two-day course just in case. <If they are crustaceans, then any copper-based medication should kill them. On the other hand, blooms of them aren't common in aquaria, and suggestive of a deeper problem. To multiply, they need food. This may be algae if you have a lot of light (including sunlight) but not enough live plants. It might also be faeces and uneaten food. If the tank doesn't have adequate mechanical filtration (essentially, current + rinsable media) then organic wastes will accumulate in the gravel, and that in turn will feed these "pests". Get rid of the food source, and their populations will quickly drop.> Does my explanation of them coincide w/ cladoceran or anything else you know? If so, how can I nip them in the bud? The LFS wasn't familiar with anything I was describing, nor had a microscope to look at my water sample, but thought maybe adding some stock that will eat on them could help control things. They suggested molly or tiger barbs. I'd hate to add anything at this point until I figure out what the heck is going on. Thoughts on their recommendation? <If this was really tiresome, and given the tank is fairly small, I'd perhaps recommend a "reboot". In other words, put the fish and some water in a bucket. Stick or connect the filter to the bucket, so that it is running. Remove everything else from the tank. Deep clean the gravel with lots of hot water, or else throw out and add new gravel. Put the tank together again. Acclimate fish to new water conditions just as you would if you'd bought them, but don't directly add any old water to the tank. Reconnect the heater, filter, etc. Sit back, knowing a job well done. All else being equal, you'll be starting from a normal baseline except that the filter is 100% mature. Any "pests" that get in there will have to go through you now, so review any plants or live foods, and take care to keep on top of hygiene. Clean the gravel, remove uneaten food, etc.> HELP!!! I want to glass fish to relax. they are getting really stressed out. THANKS as always. Gosh - how could I do this without you all at WetWeb?! Kristi <Well, I hope this helps, and thanks for the kind words. Cheers, Neale.>

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