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FAQs on Aquatic Insects and Freshwater Aquariums 1

Related Articles: Invertebrates in Freshwater Aquariums, Invertebrates for Freshwater Aquariums by Neale Monks,

Related FAQs: Aquatic Insects 1, Aquatic Insects 2, Aquatic Insects 3, Aquatic Insects 4, & FW Invert.s 1, FW Invert.s 2, Hydra, Worms, Crustaceans, Shrimps, Crayfishes, W and Brackish Crabs, Terrestrial Hermit Crabs,

May look like a worm, but this is an insect larvae.

Spiders in my silver dollar tank 5/8/2009
Hi guys,
I have Googled till I'm cross-eyed, but still can't find any advice on a creature I've found in my tank when vacuuming.
It looks like a silver grey spider, body about 5 mm long, 3 mm wide, 6 legs, and is quite active. The total leg span would be about 1.5cm.
<Well, if it has six legs, it's an insect. My guess would be a Damselfly larva; these are quite commonly seen in fish tanks, coming in with aquatic plants and portions of live food. They are predatory, but beyond fish fry, it's hard to imagine them causing real harm.>
It was cleaning the muck off its feet in the bottom of the bucket and is quite cute. I'm reluctant to kill it or to put it back incase it's a parasite and my harm my large silver dollars.
<Damsel- and Dragonfly larvae are indeed fascinating animals, and easy enough to rear in floating breeding traps. They can be hand-fed live or (wet) frozen bloodworms using forceps.>
I know they're not in the right tank, I have a large bio-orb, which is actually difficult to clean as the filter sits in the bottom of the orb and is quite small, but they grew so quickly, I'll need to buy another tank.
<I'll say! Just as an aside, BiOrb tanks may look good, but in terms of fishkeeping, they're very poor value for a whole host of reasons. Stick to traditional long, rectangular shapes. Avoid anything tall, round, or otherwise odd in shape.>
My local aquarium isn't much assistance, they couldn't identify the leech, red thread worms, or little white flea like creatures.
Still, thanks for your advice.
<Happy to help.>
I'm loving owning fish and there's so much to learn. I now have 5 tanks!
Started from one, but fish grew, bred, had personality issues.... I'd better learn quickly.
<Cheers, Neale.>

Identify Worm 11/23/08 I live in coastal SC and I kept my turtle tank outside during the summer and fall. I just brought it in for routine cleaning and because of cold weather. The tank had some strange "worms" that looked a little like "naked caterpillars with long string-like tails." The ones that were moving were a fleshy tan color. There were also some that were black or dark brown and very hard. Some of them were in the water but some were attached together by the "strings" and hanging off of a rock in the tank. I have looked on many sites and tried many different search terms but am not coming up with an answer. Please help me identify this strange little creature. Brandi <Hello Brandi. What you're describing is almost certainly a "rat-tailed maggot", a distinctive fly larva that inhabits stagnant water. The long "tail" is a breathing tube. They're pretty much harmless, and in England at least very common in small, unfiltered ponds. Fish (and likely turtles) don't seem to eat them, or at least my fish don't! Cheers, Neale.>

Strange Creatures in FW tank 9/20/08
Hi people
On performing a water change earlier today, i noticed a couple of odd creatures which came from within the gravel of my goldfish tank. Any idea whether these be friend or foe. Actual size is around 12mm (½?) in length...
Thanks in advance J
<Hello! This URL asks for a log-in and password. How about just sending a small (max, 500 k) attachment? That's what most folks do, and we thank them for it. In the meantime, most small bugs and worms in fish tanks are harmless. Cheers, Neale.>

Strange Creatures in FW tank
Hi Neale
On performing a water change earlier today, i noticed a couple of odd creatures which came from within the gravel of my goldfish tank. Any idea whether these be friend or foe. Actual size is around 12mm (½?) in length...
<Hi Brad. This is, I believe, a Damselfly larvae; looks like a Dragonfly nymph, but the give-away is the "tail" made from three filaments. Dragonfly larvae are bigger, have more robust jaws, and a stubby "tail". Damselfly nymphs are predatory, but only sufficiently large to take small fish, perhaps livebearer fry. Otherwise they're fish food! Quite fun to rear yourself, they can be hand fed bloodworms with forceps, and it's rather fun to watch their bizarre mouths anatomy in action. Dragonfly larvae are much more dangerous to fish, some varieties being anything up to around 8 cm/3" long (at least here in England) and more than capable of eating things like minnows. In any case, almost certainly came in with live plants that were grown outdoors, though possibly in batches of things like Daphnia. Does rather stretch the imagination to assume either a Damselfly or Dragonfly flew into your home and laid its eggs there, but it's possible I suppose! Cheers, Neale.>

Re: Strange Creatures in FW tank 9/21/08
Hi Neale
Thank you for the response. Since I only have large-ish goldfish in the tank, looks like they will not be a problem. I do buy live plants for my fish to snack on, so I guess that was the ticket in for the larvae.
Thanks again
Brad :)
<Hi Brad. Those Damselfly larvae should cause no harm to your Goldfish; in fact I'm surprised they haven't been eaten yet! Cheers, Neale.>

Fly Larvae in Turtle Tank, shoo fly, shoo 6/29/2011
Dear Crew,
<Hiya! Darrel here>
I have a problem with larvae getting into the filters.
<I hate when that happens>
I know there's been questions like this asked but normally they describe white circles or worms that swim around in the water and are parasites.
<A parasite swimming around in the water sounds more like my brother-in-law on vacation in Hawaii>
I know that the larvae grow up to be some type of flying insect, not sure what kind but they look almost like fruit flies. So here's the deal:
I have a year 1/2 old Red Eared Slider who resides in a 20 gallon aquarium with a waterfall type filter and a real log.
<Real wood gets really waterlogged and grows real fungus eventually. An alternative might be some sort of rock or plasticized wood often sold in aquarium stores for tank decoration>
There have been dark black-brown worm-like larvae crawling on the filters when I clean the tank every week 1/2 - 2 weeks. I'm not sure when they start to develop but by the week 1/2 point there is normally one or two types of flies surrounding the tank;
<Sounds attractive, huh?>
While some may be getting in from outside and being attracted to the heat lamp, the larvae have been growing on the filters for a couple months and the filters have been replaced every time I've cleaned them. Do you know what this could be caused by?
He eats Omega One Adult Turtle Sticks and the filters seem to have a type of rock in them and are white rectangles.
<Ceramic cells that encourage bio-filtration>
I'm not sure of the brand at this time.
<Many brands '¦ same stuff>
He was found in a pipeline in a steel mill and rescued by my half-sister's dad who gave him to us.
<Thanks, Dad!! That was really nice of you.>
Thanks for your help, and sorry if this has been asked already!
<No apologies necessary, Courtney. It happens all the time>
<The answer is most likely that you've never fully killed the eggs, so some hatch and pupate before you even notice and in turn mature and lay new eggs.>
<So here's what I'd do: Take Piper ('cuz you'd name a turtle from a pipe Piper, right?) out of the tank and find him a new place to live for a few days. Someplace warm and DRY. We're going to keep him out of water except for 15 minutes a day when you put him in a shallow container of water with a bit of food. He'll eat & drink and hopefully he'll poop. If he poops in the container water, which you're flushing - any eggs in his digestive tract will be eliminated from the cycle. If he poops in his dry box, the eggs will likely not hatch anyway, but you're still cleaning that up daily.>
<Meanwhile, leave his tank intact. Water to the regular "full" level and maybe even an inch more. Add 1 cup of chlorine bleach per approximate gallon of water. Even a bit more is OK as long as you can ventilate the room so no one breathes the fumes. It's important that you leave the filters on and running during this process. What we want to do is kill the larvae and eggs everywhere -- inside the tubes, down in the impeller -- all the places you'd never reach with even the most thorough cleaning. After 24 hours, you can drain the water, break the system down and clean everything. Rinse, use soap and water, rinse again & then set it back up.>
<Let it run clean & sterile for another 3 days, then put Piper back in. Chances are that you'll have broken the larvae cycle>
<How was THAT as an answer on a scale of 1 to 10???>

... English? Shrimp... Odonatans... 1/11/11
okay in my shrimp tank I have some kind of dragonfly naiad(I think that's whats its called) It has six legs black in color( i seen a pic on one web site but it didn't have a name they just called it a dragonfly naiad-- and you have to have permission to use the pic.)
I need to know if they would eat my shrimp.(Ghost & Cherry)
altho I have lost about 14 (combined) of them. I wrote before about some kind of worm/snail that Ive been taking out when i see one, and they will not live out of the water. usually about 30 sec or so they dry up. they are very soft body, slimy feel, black in color (Looks white inside on glass) long bodied but can move like a snail but it only attaches with the head on the glass. head is traingle when streched out. is this part of the dragon fly i found and could there be more since i found this big one in the tank.
unfornately the tank is filthy but cant clean it due to the thousands of (ihope )baby shrimp
need help with that also anyway anything on the creatures would be nice and if you want i could send actual samples of these creatures.
<Uh, no... see below... need to be removed likely>
Judy Potts
<Judy, please run your writing through a spelling and grammar check before sending. See Net re how to do this if unfamiliar.
And read here: the http://wetwebmedia.com/FWSubWebIndex/fwaqinsectfaqs.htm
Bob Fenner>
re: 1/11/11
Okay so sorry for the misspelling here. I went and saw what the creature was and a gentleman named Neale said it was a Odonata.(on the website)
Since that what it is,What do the larve look like?
<? Look up via your search engine/s... Dragonfly Nymphs...>
Is it best to take out the grown shrimp and just clean the tank?
<... read where you were referred. B>
What should I do? I also notice white creatures round body with two little white dots following the round body.(Magnafing glass helps) The others look like the baby shrimp I thought they were,but not growing at all. They have the long body and really look like shrimp. I apologize for not being more informal on the topic, but Neale has helped me so many times that I trust you with the info that is provided on your website. Again I hope I did a better spelling than before.LOL
Judy Potts

Ftn. leeches?? 12/17/10
I have found small red worms that strongly resemble ones discussed on these two pages http://www.wetwebmedia.com/fwsubwebindex/tapewmfwf.htm
in a freshwater outdoor water fountain (with no fish). When I go to change the water every other day or so they float up and are swept out of the fountain and into the flowerbed. Birds use the fountain to drink and I imagine that mammals use it at night. I have red wriggler earthworms and décolleté snails in the yard also, but never find them in the water fountain.
My questions are;
Are they harmful to birds, cats or skunks etc?
<Can't tell with the information presented... All Leeches are parasitic...
can't/don't live long w/o hosts. Do yours show segmentation, suckers?>
If they are harmful how do I eliminate them?
<Simple bleach>
Is it possible to 'dose' the water to prevent their return?
<Depends on the source...>
I don't currently have a pet but when I did she did drink out of the fountain, when I get another will I have to prevent it from doing this?
Thanks, Pam Kelso
<Welcome. Bob Fenner>
Re: leeches?? 12/18/10
Thank you for the reply. In rummaging around the internet after I sent this to you I think that I have identified the culprits. They are midge fly larvae, bloodworms.
<Ahh! Quite common to have such insects w/ aquatic larval stages using water features opportunistically. And not a disease issue>
Because I clean out the fountain every few days I never saw them at maturity and they were always small and non-segmented. I know that we have midge flies so I think that solves it. Thank you for getting back to me so quickly.
Pam Kelso
<Welcome. BobF>

Damselfly nymph 10/10/10
I have a 20g long shrimp only tank with a medium-fine gravel substrate, planted with Sagittaria, hornwort, java fern (medium density). 2x 18w bulbs, nothing out of the ordinary. Housing maybe 20 RCS, 15% water change weekly. pH ~ 7.6, all chemistries 0. I have found myself a damselfly nymph (am led to believe is this, and not dragonfly, due to longer, more slender body). Question is, are they detrimental to RCS population? I have removed one I saw (is roughly 1' long), do not see others. Is this a 'keep eyes open for more and take out as needed' deal, or something more drastic? I don't want to break this tank down for this. Any advice appreciated.
<Brandon, Damselfly nymphs are predators, and they will eat very small animals of all types, including fish fry. Whether they can actually kill an adult shrimp is questionable, but they might take juveniles. Of course Damselfly nymphs do need to eat *something*, so unless you're providing suitable live or wet-frozen food for them -- they suck the juices out using their jaws -- it's probably best to move the nymph to a pond nearby. They're neat animals, and the adults are beautiful and in some cases endangered. One last thing, Damselfly nymphs are distinct from Dragonfly nymphs in having three breathing tubes at the tail-end of their abdomen, structures that Dragonfly nymphs lack. Cheers, Neale.>
Re: Damselfly nymph 10/10/10
Indeed a damselfly nymph then.
I have moved said nymph to another location, but in the absence of naked-eye visible ones, is it likely there are more?
<Unlikely. This is indoors? Unless you have damselflies flying around your home, it's most likely this one came via plants or live food, both of which can be cultivated outdoors or in large glasshouses where damselflies might be buzzing about.>
I suppose it's just a keep watch, remove as needed affair?
Probably half my shrimp are berried at various stages, so I don't believe population-wise the nymphs will pose an issue, unless they appear in large numbers. Just keep eyes open and remove PRN?
<Pretty much. They're such neat animals, you might even choose to keep one as a pet. Some remain in their nymph form for months, even a couple of years, depending on water temperature. I've used forceps to feed them wet-frozen bloodworms, and various small live foods such as glassworms will be taken, so they aren't difficult to maintain. Cheers, Neale.>

identity of small black wriggly worms/larvae 9/17/10
Hi! We're currently residing in Manila, Philippines. It's happened twice already wherein we found more than a dozen thin black wriggly larvae on the countertop of our bathroom sink. It seems like they just magically appear out of nowhere.
<Almost certainly some sort of Dipteran larvae.>
They wriggle their heads and tail ends from side to side. Really gross!
<Nothing in nature is "gross", merely different.>
I'm afraid they're harmful parasites.
<Very unlikely.>
I'm worried for my kids.
<Don't be.>
Help! What are they? And how do we prevent them from reappearing.
<Dipterans tend to be attracted to moist, warm places with organic matter on which they can feed. There are many types of Dipteran, including things like house-flies and mosquitoes through to more obscure species. Dipterans dislike dry houses with nothing for them to eat, and the are eaten by spiders and carnivorous plants. So there are some clues there about what you can do to minimise problems with Dipterans.>
Thanks so much for your help!
<Please understand we aren't environmental health consultants; we're fishkeepers. If you're concerned about pest animals inside your home, you need to speak to genuine experts. Only your doctor will be able to tell you if these organisms are a threat to your health, and only pest control professionals will be able to determine why these animals are getting into your home. So take my diagnosis for what it is, speculation on the part of a non-expert. In no way is WetWebMedia liable for any health or other problems caused by these larvae or your subsequent actions. Cheers, Neale.>

Worm Identification 8/30/10
I found a worm in my drinking glass this morning. I assume it came in through my tap water. Could you help me identify it?
Thank you.
<It's not a worm; it's an insect. Some sort of Dipteran larvae, e.g., a midge. Harmless, and an excellent fish food! Cheers, Neale.>

Mysterious white worms (in a freshwater tank) 3/10/10
Good morning!
I am a first time WWM email user. And I find your website tons of help! I have a question. This morning I cleaned my fish tank and I saw tiny white worm-like creatures on the glass of the fish tank.
<Likely free-living nematodes and planarians. Not in themselves dangerous, but a sign that this tank gets too much food and not enough cleaning, since they feed on uneaten fish food (among other things). In most tanks you might find a few, but not enough to notice. If there are obviously lots and lots of them, then you have a problem.>
Also while I was using my siphon I stirred the gravel a little bit and 1-2 inch white worms and my angelfish and guppies started to have a feast, when I looked in my bucket I saw 50 maybe 100 of them and I'm worried. They swim in kind of a S shape and when they stick to the glass they move kind of like an inch worm. Kind of creepy.
<Just nature mopping up the mess you're making. Like cockroaches in a kitchen.>
I also tried a parasite med. But. I don't think that worked ;(
<Why would it? These aren't parasites. More significantly, trying to kill a bunch of animals in your aquarium means you're going to end up with lots of decay, and that means poor water quality. Imagine if you killed off a nest of rats with rat poison, but just left the bodies to rot. Bad. The correct approach here is to ignore the worms, and instead control their numbers so the population dies back over time. How do you do that? By limiting the amount of food they get to eat. Feed in sensible amounts, don't overstock your tanks, and remove uneaten food at once.>
Thank you for your time helping me!
<Cheers, Neale.>

Worms 09/04/2008 Hi I have a 29 gallon freshwater tank it is a fairly new tank only been up for about 7 weeks.. I just got done battling ick on my swordtail fry and then today I noticed these brown worm looking things on the glass of the tank near the top ,but they were not in the water at the time I found them they were actually just above the surface.. I wiped them off but not sure if they are a worm or some type of insect larvae.. I have attached 2 photos, not the best because they are very small.. I tried looking it up myself but all I can find is references to white worms which these are not white.. Are they harmful? I already did a 20% water change while vacuuming the gravel today.. Thanks Trish <Hello Trish. The "worm" in question appears to be an insect larva. Certainly to my eyes it seems to be segmented and possesses small appendages of various types. In other words, a maggot. No immediate threat to the fish, but a good sign that there's a lot of decaying organic material somewhere in or around the tank. Otherwise the parent fly (or whatever) wouldn't have laid its eggs here. So time for an early spring clean! Cheers, Neale.>
Re: worms 09/04/2008
Thank You.. I did vacuum the gravel out today after finding the worm like things.. and there was a lot of food in the gravel.. I didn't realize I was overfeeding , I only feed them once a day but I guess I need to cut down on the amount I am giving each day.. Thanks so much for your speedy response. Trish <Hi Trish. Overfeeding is easy to do, and much more difficult than to under-feed! Remember the two golden rules: Firstly, little but often. Snacking is better than gorging. The fish are more likely to eat all the food, and they'll also extract more nutrition with less wastage. Secondly, use the minimum quantity, and it should all be gone within a minute (for the average greedy community fish). Remove anything leftover; a turkey baster is a great tool for this, allowing you to pipette out stuff without buckets or getting your hands wet. Cheers, Neale.>
PLANTED TANK WORMS - 7/24/08 I spotted this tiny brown worm on three of my freshwater aquarium plants this morning. Some are so small they look like dust. I removed them all with a turkey baster. My research didn't turn up anything. Can you identify them by the attached photo? Should I be concerned? Thanks for any help you can give me. You guys do a great job. Bob <Hi Bob. The photo is a bit small to say anything sensible, but my guess (and that's all it is) is that this is nothing more serious than some sort of insect larva. Common enough in freshwater habitats, but usually get eaten by fish if they end up in aquaria! In any event, very, very unlikely to cause any harm. If you're concerned, remove them and feed them to your fish. I'd be tempted to rear them in a small container of water just to see what they turned into. They aren't mosquitoes or anything noxious like that. Cheers, Neale.>

Re: PLANTED TANK WORMS Thanks Neale! <You're welcome, Bob.>

George in Greece... worms, copepod... ID 03/16/08 Dear Bob, As you can see in the photo there are two types of worms and one type of copepod (freshwater). <Can barely make these out> We are extremely interested in finding out the following: a) species and if not, genus or even family. b) are they harmful to fish (esp. fry) Your response will be greatly appreciated. George & Marina <The blue thing is obviously some sort of dipteran larva; the red things perhaps small oligochaetes, but it's difficult to say. In either case they're fish food rather than a problem! Fish fry *might* be harmed -- I've lost baby Corydoras to planarians, for example. But I suspect that the usual problem is that if the water (or substrate) are "dirty" (bacteria-laden) enough to support these small life forms, newly-hatched fish are at greater risk of fungal infections. So in my case at least, the planarians didn't kill the Corydoras fry, but simply attacked the moribund ones. That'd be my guess, anyway. Cheers, Neale>

Stranger (damselfly naiad) in my community tank -03/13/08 Hey guys. This morning I noticed a strange-looking bug in my 10 gallon community tank, which houses 3 guppies (tuxedo, sunrise, and fancy), 2 Hatchetfish, and 1-2 Otocinclus (there should be two, but I haven't seen them both at once in a long time, though I haven't seen any bodies...) After doing some research, I determined that the bug in my tank is a damselfly naiad. I think it must have come in on the live plants I ordered from Drs. Foster and Smith. In my research, I also learned that the damselfly is carnivorous, and will eat small fish, which, obviously, includes my guppies and Otos. I don't really want to kill the bug, but I also don't want to run the risk that it'll eat my little guys in there if I leave it be. Do you think this is a risk I should be concerned about? Would it be better to try to net the bug and transfer it to my 55 gallon cichlid tank? I feel fairly confident that the cichlids can fend for themselves against a carnivorous bug. I'm just always wary of adding contaminants to any tank. Any thoughts? I'd like to keep the bug just because I think it'd be really neat to watch it go through its 2 year metamorphosis, and also because the idea of a semi-complete ecosystem is so darn cool. Thanks for your input! Micah <Hello Micah. Damselfly larvae are quite distinctive thanks to their big bug eyes, long bodies, and three "tails" at the end of the abdomen. They are relatively easy to maintain. Yes, they will eat small fish. But bigger fish will eat the damselfly larvae! Set up its own aquarium using anything that holds a couple gallons of water; even a goldfish bowl will do. If you can, add a simple air-powered sponge filter, but that's not essential. Fill with water from your aquarium, cooled down to room temperature. Add some hornwort, and then some live daphnia and pond snails. Voila! Your very own safe indoor pond. Put somewhere sunny but not in strong direct sunlight (you don't want it to overheat!). Sit back and enjoy. The larva will eat daphnia but they also enjoy bloodworms, live or frozen. To get them to eat frozen bloodworms, use forceps to dangle the food enticingly. Damselfly larvae are quite common in shipments of coldwater and pond plants, but most people don't notice because the fish eat them. Cheers, Neale.>

Re: Stranger (damselfly naiad) in my community tank -03/13/08 haha, thanks Neale! <No problems.> I have a simple question that I feel foolish asking... Where on earth do I get live daphnia? Internet only? I found a site that sells a "daphnia instant culture kit" at http://www.hometrainingtools.com/catalog/life-science-biology/ocean-water-life/p_lm-insdaph.html but that site does also sell live daphnia for substantially more (shipping costs and whatnot). <Usually sold in pet stores to feed fish. If not, don't worry about it. You can look after this beastie with nothing more than frozen bloodworms and frozen mosquito larvae. Daphnia can usually be found in garden ponds, especially once it warms up. A fish net is fine for catching them. I get all mine from me neighbour's pond!> I actually do have a 10 gallon tank that I'm currently not using, which I could fill halfway and gleefully transfer any number of the common pond snails that have taken up residence in my little community tank. <Very good.> I'm excited for this small indoor pond of mine (though, it will have to have a lid, as my cats are not the timid sort). <Likely not a problem. Cats show little interest in small aquatic invertebrates. They may choose to drink the water, but that won't do any harm. As you probably know, cats can't bear the chlorinated water we use, and aquarium water is considered by them much more toothsome!> Thanks again! Micah <Cheers, Neale.>

Please Help Get Rid of my Flies!!!!(My last resort) 2/10/08 Hello I have scoured The net looking for a question and my LFS recommended this site, so here we go. First of I am running a 65 gallon fresh water tank. Two HOB Bio Wheels. Heater etc. . My temperature is usually aprox 77/78 deg. There are two prismatic lens covers on my aquarium. The transparent kind you see under fluorescents in stores/ schools. With aprox 6 inch square of open space on each one. There are 4 Platys 1 Sail Fin P#lco(2.5-3inc) <A what...?> and 12 harlequin Rasboras. The nature of my problem are tiny green flies. They first appeared on the surface of my water as see threw shells. Within a day they "fly away" and get stuck under my lid. My LFS said they could not be actually flies on the water surface and must be a aquarium pest. Where as since then, I have definably seen them fly away. When they Grow wings and get bigger aprox 1/2 mm they change into a fluorescent green. They are located around my filters , and are reproducing fast. Some one suggested they are coming from my filter pads. Whereas they are under water. Dose that make sense. The only new addition to the tank was a batch of aquarium moss. Which has since been removed. Where as the flies still reproduce and cause me a large head ache. I clean the inside of the lids every two days now and there are between 30 and 100 every time. They are so small that when on the water surface my fish cant see them as such cant eat them either. That is all I know. Presently I am syphoning water from the surface at my water changes to attempt to rid them of my tank. Like I said removed all new additions and am maintaining a regular water change schedule 10/15% every 2/3 days. Any help would be great. Ps have no photos where as I can try and resend the email towards the end of the week If need be with new photos. Just email me and ask thank you ever so much. You are my last resort. <Well, not precisely sure what these "flies" are, but I also doubt they are actually true flies, i.e., Diptera. Fish usually DEVOUR dipteran larvae, and there's not much chance a population of mosquitoes or some other (semi-) aquatic fly could actually maintain a population in a fish tank. It is much more likely you have thrips or some other insect that walks on the surface of the water. Now, there are two key things to known. Firstly, they don't do any harm. Most freshwater tanks have played host to these at some point. They don't carry diseases and they don't harm your fish. The second thing is that they don't break the laws of physics: if they're multiplying, its because they're finding something to eat, most likely decaying fish food. You don't see these insects in clean tanks with strong water currents. You see them in tanks with variable levels of cleanliness and filters insufficient for the tank/population of fish. Even adjusting the filters so that there is more water circulation will make a difference. In any case, these insects migrate into the tank from the rest of the house. They'll come from other warm, moist places. You can't exterminate them so either make the tank less attractive for them, or simply ignore them. Cheers, Neale.>

Strange critters in my tank(s), FW aquatic insects 2/1/08 After several days of scouring the web for answers, I'm still no closer to identifying this critter. So far I have found 3 - two very tiny, and one that's now about 3/4 inch long. When I saw them swimming I observed that they moved with a sort of eel-like motion, but they are definitely not worms (as I thought when I had only seen the tiny ones). These have 6 jointed legs (looking much like a spider's legs) at the "head" end, no legs on the bright green body (which looks to be segmented, but since it is so small it's hard to tell). It's about as thick as a pencil lead and at the other end is a sort of finned tail with 3 distinct "fins" which, unlike the body, are marked with dark bands. When resting right-side-up, this critter uses the two outer "fins" to hold up its tail end, and the middle "fin" stands straight up. When swimming the "fins" are folded and look like a darker extension of the body. When the critter (presumably) sleeps, the fins are also folded together and the 3 separate appendages can't be distinguished. I found the first of these when I was doing a water change in the large tank (200 liter) and the second and third while doing a water change in the fry tank. The first two were less than 1/4 inch long and the colors were not apparent at that stage. They just looked like short, very thin wiggly things with larger heads and I first assumed they were some type of worm. However, given the 6 legs and fin-like tail sections I realize they're totally un-wormlike. Not knowing what they were, I put the largest of the 3 in a small glass of water and he's been there now for a couple of weeks. In that time he hasn't gotten any bigger, and crumbs of fish food went untouched. A few days ago I put in some dried and fresh bits of various leaves to see if he would eat them. Until then he had stayed at the bottom of the glass, supporting himself on his legs and the two outer "fins" - but the first day he somehow noticed the floating vegetation (I say "somehow" because before then I had never seen him move from the bottom, do any exploring, etc.) and has now relocated himself to the underside of a floating bit of (dried) leaf, folded his "fins" and settled in at his new location. It's just not possible to get a good photo of him - though I did try - so that his head, legs and "fins" are visible. The fry tank sits on a low table beside a medium-sized potted Sheffler which from time to time gets infested with those tiny pesky gnat-things that crawl around on the surface of the potting medium. Not whiteflies, but I don't know what they're called. However, I've never seen the gnats look anything like this in any stage of their development, and there are no other plants/pests in the immediate vicinity of the tank. The little table is, however, next to the balcony door (which I tend to leave open when the weather is nice, though that doesn't happen often here) and on the balcony I have probably 60 or 70 plants of different types, none of which have had any pests aside from the occasional snail. I considered the possibility that my critters came in from the outside and from there to the fry tank, possibly transferred to the main tank on a communal net or something. But that's quite a bit of guesswork, and I'd like to know for sure what this is and what (if anything) I should do about it. My partner thinks they're mosquitoes. However, we have had sub-freezing and inhospitable weather this winter, and I can't imagine that mosquito larvae would be already hatching. It hasn't gone above 8 C. for at least two months. In addition, this mystery critter is already bigger than any mosquito I've ever seen - even in southern Louisiana. :P Does anyone have any ideas? Please? Hopefully, Erin <Erin, without a photo difficult to say, but if the thing has three filaments (actually gills) coming from the tail-end, then it's mostly like a damselfly larva (Order: Odonata; Suborder Zygoptera). Quite common in ponds, and they sometimes get into aquaria with live food or on plants. They are predatory, and eat things like smaller insects as well as fish fry. They won't (likely can't) eat dried food. Cheers, Neale.>

Red Worm ID (Royal Plec) 11/19/07 I've had a 3 1/2" Olive Royal Plec alone in quarantine for 10 days or so. I dewormed with Praziquantel last week at the recommend dosage (76 mg/10 g) as I know they're wild caught and don't want to pass anything onto my own fish. He went into a 20 gal tank with new aged water and a fully cycled Penguin 280 bio-wheel filter from another tank. I did his 25% water change today (after leaving the Praziquantel in 5 days) and found these live red worms (pic attached) in the water I syphoned off the bottom of the tank. Pretty wiggly and entertaining under the microscope but I can't figure out what they are via the FAQ's. If they weren't alive I'd have thought they were frozen bloodworms. I'm hoping it's a harmless worm that can be treated as the Plec is eventually going in with my much loved Severum. I promise not to bother you anymore, but maybe the picture will help others. Mitzi <Looks like a chironomid larva (a.k.a. midge larva or bloodworm) to me. Probably got in with some live food. Usually get eaten by fish, so not common in aquaria. But if this tank was empty for a while, then it's possible a midge laid some eggs there. In any case, harmless. Cheers, Neale.>

Re: Red Worm ID (Royal Plec) 11/19/07 Thanks, Neale. I feel stupid then but thankfully that's good news. I never feed live food, but the driftwood in his tank had been soaking for a month in a large kiddie pool outside. I rinsed it off real well but I bet that's where the bloodworms came from. (The tank had been empty and stored before he went in it). What a relief! Mitzi <Mitzi, Glad we have a happy ending here! Cheers, Neale.>

Worms in fresh water aquarium 11/29/07 Hi WWM My sister has a fresh water Aquarium which she just cleaned out on the weekend, and a few days later we have noticed these worm like creatures in the filter tubes no where else but in them. They have small legs and are hatching out of these things that look like cocoons and if you look carefully at them they have small mouths. There very disturbing to look at and gross us out. There's so many of them please help! Jessica <Hello Jessica. Without a photo its impossible to say what they are. But given they have obvious limbs and mouthparts, one must assume they are some sort of insect. Aquatic insects vary in their danger to aquarium fish: most are simply fish-food, but a few, particularly dragonfly (Odonata) and beetle (Coleoptera) larvae, can turn the tables and will catch and eat small fish. If you can send a picture, we can try and identify your visitors with a bit more precision. Cheers, Neale.>

Re: Alaskan Isopod! One Id down, now on to the Water Beetle! 11/16/07 <Hi Jack!> Thanks for identifying the isopod for us. <You're very welcome!> It is known locally by Inupiat Eskimos as a "toe biter". I doubted they had the ability to bite toes, but perhaps they actually do. <I would imagine so. Those isopods can get relatively large - around 3'. I sure wouldn't want one grabbing hold of my toe!> We have a large(3 cm) water beetle living in the same aquarium as our specimens of Saduria entomon. It preyed upon our snails and is now preying upon the S. entomon. <Ah yes, I see. The predator becomes the prey!> I have had trouble identifying it and hope that you can help. <Hope so> It breathes with head down and stores a large air bubble in its tail region. <Typical> It is quite buoyant and uses a lot of energy to dive. <I've seen videos of this. It looks extremely awkward, and reminds me of trying to see how deep/far I could swim with an inner tube around me as a kid! LOL I didn't do as well as these insects, and I'm very thankful that there are no existing videos to prove it! Regarding identification, unfortunately, insects are not my strong point. What I can tell you is that since it's a predacious diving beetle, it's most likely in the family Dytiscidae. This family, though, has many, many genera and species in it. The good news is that I found the following link that supplies a list, for Alaska, that narrows it down considerably: http://www.uaf.edu/museum/ento/Insect_Omnibus/Dytiscidae/ The next, tedious, step would be to go through that list and look up each specie on the internet. If you do a search based on images, it goes a lot quicker! I looked through about a third of those listed, and saw one that appeared similar - Dytiscus circumcinctus. Here's the link that shows this specie: http://www.hlasek.com/dytiscus_circumcinctus_ac7200.html Problem is, while it looks like yours does have something of a light border around the anterior edges, it doesn't look like it extends all the way around as is shown at the link. If this is indeed the case, then it's back to old drawing board - or in this case: the search engine!> Thanks for any help that you can provide. <You're very welcome, I just wish I could have given you a definitive answer!> Jack Adams White Mountain High School We are located on the Seward Peninsula in Northwestern Alaska. <Indeed a beautiful area, that's a fact! Take care --Lynn>

Water Bug? -- 10/18/07 I'm not sure what it is or how it got into my tank. Is it potentially dangerous to my fish? Could there be more? It's a little less than half an inch. My apologies for the bad picture. <It's almost certainly a dragonfly (order Odonata) larva of some type; and yes, they're predatory. Absolutely fascinating animals to keep in their own aquarium or bowl, but not safe with fishes. Easy to keep, and you can even hand-feed them bloodworms using forceps or similar. Take many months to mature in some cases. Impressive jaws, and if anything these insects are even more interesting than the fish we commonly keep. (Rather like mantis shrimps, which are *far* more interesting than the average coral, despite being viewed as pests!) Usually these things get into tanks with live food or aquarium plants. The parents lay the eggs directly in the water, and the aquatic larvae can't fly from one pond to another. So it got into your tank because you put it there, albeit unintentionally. Cheers, Neale.>

Wiggly worms and Scary Fish Questions! Insect larvae... plus bizarre Macropodus obs. -- 09/29/07 About a month ago I started up a 10 gallon freshwater tank. In the tank I have 2 gala <Heee! Likely Bala... Balantiocheilus... needs much more room than here> sharks, two tiger barbs, <Keep your eye on... nippy> and 2 blue paradise fish. I set up the tank with an under gravel filter. A few days ago I went to replace the under gravel filter for a regular power filter because the tubes that contain the air stones in the under gravel were clogged with a brownish algae. That's when I noticed these tiny white worms wiggling all over the lid. They didn't seem to want to be IN the water although the lid stays very wet. What could have caused these worms? <Likely terrestrial insects... larvae. Can just wipe away...> (A fruit fly laying eggs because of the algae in the tubing above the water is what someone told me?) my second concern is about one of my paradise fish. All of the fish in my tank are pretty mellow (not because they are unhealthy) but occasionally one of my paradise fish does this strange thing with its mouth. Its upper lip moves away from its head and exposes this thin "nose-like" membrane. It swims around like that for a while and then it will suck its lip back in and look normal. What is that all about?! <Got me... can you send a pic?> Please Help!! thanks, Sammy <BobbyF>

My fishes are bloated!!! HELP! 10/14/07 I emailed you about a month ago about some tiny white worms that were crawling all over my 10 gallon tanks lid. you suggested that they may just be terrestrial but? I was wondering if these could be parasites of some kind. <Mmm, no. Some terrestrial insects do have larval forms that are predaceous on aquatic life though...> They have little black heads and a little black tip on the end of their tails. They are REALLY tiny like almost unseen unless you know they are there? and live in what looks like food splashed on to the lid from the tank. I feed the fish at night and wipe the tank lid clean every morning but still notice these little worms. Also, about two days ago one of my blue paradise fish died. Its stomach looked swollen and it just floated around bumping into things? at bottom of the tank until it died. Now both of my tiger barbs and one of my gala sharks are bloated looking!? I still have one paradise fish and another? shark that aren't affected? yet.)? is there anything that i can do to get rid of these worms and keep my fish from dying!? please help! Sammy <Mmmmm, well, the fishes might be consuming this life... and this might be mal-affecting them... I would try taking the top off... cleaning it thoroughly, wiping under the rim of the tank... to see if you can eradicate whatever this is for good. Bob Fenner>

Tiny white bugs/crustaceans, FW... 8/29/07 Hi. Hope you can help me with this one! <Will try.> I have a 5 gallon freshwater aquarium with a betta fish in it. A few months ago I noticed a few things: 1) tiny white bugs, barely visible to the naked eye, that swim/jump through the water and sometimes scoot along the surface of the glass <Those are very small insects or insect-like animals. Thrips, collembolans, mites, and so on. Harmless.> 2) tiny things that stick to the glass and plants. They remind me of barnacles more than anything else. They are scale-like, flat, transparent beige in color, and have a small red-orange colored center. They start out as specks on the glass and progressively grow bigger, to about the size of a pin-head. They have a hard outer "shell"....I know because I've been killing them off as best I can ("crunch"), but they continue to multiply. <Sounds like snails of some sort. Basically harmless.> 3) tiny red-orange bugs that jump/scoot on the surface of the water, which remind me of mites or water spiders or chiggers. <Again, some sort of harmless arthropod. Quite possible red mites.> I have no idea what any of these are, and my internet research thus far has not helped. I'm wondering it is it possibly a single organism that I am witnessing at different points in it's life growth cycle?? <No, not really. Aquaria become ecosystems of a sort, and animals in house attracted to warm, damp places congregate on them. Hence you find the same sorts of things on the aquarium as you'll find in the bathroom.> A few weeks ago I did a major overhaul of my tank. I boiled the gravel, driftwood, and filtration components. I threw away all the plants. I replaced all but about 10% of the water. Two weeks later, there are tons more of the white bugs, and I'm seeing more and more of the "scale" looking things on the glass everyday. <You can't get rid of them. Remove them, and more will move in from your house. I'm guessing your tank doesn't have a proper filter; these little arthropods don't tend to be such a pest where the surface of the water is agitated by a filter. In "bowl" type situations, the still water surface is a perfect habitat for them. Furthermore, in betta bowls the water tends to have lots of nitrate and organic material in it because the volume is so small, and this encourages the growth of algae and molds. It is these that the little arthropods are feeding on. In bigger tanks with proper filtration, there's less of this stuff, and so the arthropods are less of a big deal.> These critters are such an EYE-SORE and NUISANCE in my Betta's home. Can you please help me diagnose this infestation and how I can get rid of them? <You can't. Learn to love them.> With gratitude, Shawna B. <Hope this helps, Neale>

Re: Loach ID 7/26/07 Wow, thanks for such a quick response. You nailed it: Misgurnus anguillicaudatus, Dojo Loach/Weather Loach. About the nymph, a goldfish bowl is sufficient? And do I need real pondweed or would fake plants suffice? And I figure he'd eat just about any bug I throw in or do they have to be water bugs? I'm very excited about what you told me and not having to get rid of him. Should be very interesting! Thanks again -John <Hi John. Weather loach is a lovely fish. One of the nicest. Hardy, cute, fun to watch, hyperactive, and totally peaceful. Just for once, a "mystery fish" story has a happy ending. Anyway, yep, the nymph will be fine in a bowl. Change some of the water every couple of days just to keep things sweet. But damselfly nymphs especially live in still water and aren't fussy. (To tell the difference: damselfly larvae have three "feathers" at the tail end, used for breathing; dragonfly larvae are a little bigger and more robust, and they don't have those feathers.) Obviously a 5 gallon tank with a air-powered sponge filter would be even better. And yes, they eat pretty much anything. Soft prey are preferred (like midge larvae). The only thing that matters is there's something floating at the surface the larvae can crawl about on. They need to breathe air periodically. Good luck. Cheers, Neale.>
Re: Loach ID, now an Odonatan! 7/28/07
Hey Neale, thanks again. He's definitely a Dragonfly Nymph. Over an inch and he has 3 spikes on his end instead of feathers. I got him the biggest bowl I could find, 2 gallons and he's got some artificial plants to crawl on. Should I stick an airstone or sponge filter in there? I have both but they aren't in use. I threw a small feeder Guppy in there to see what happens, hopefully he can catch him. I just don't know where to find or what kind of food, live or prepared, to feed him. Any suggestions? I live in suburban Atlanta with a lot of woods but not many ponds or anything to speak of. Oh, and I noticed him sticking his tail out of the water just like you said, pretty cool. Thank you in advance. All the best, -John <Hi John. If you have a little sponge filter, then by all means add it to the tank. As you have learned, this nymphs breathe air, and this allows them to live in pretty swampy environments. But keeping the water clean will certainly help. In terms of food, they will eat very small fish. Potentially a guppy, though typically they feed on fry rather than adult fish. Otherwise, they will eat a variety of things. I've fed them using frozen bloodworms held in front of them with tweezers. If you have a garden or balcony, nothing beats setting up a "water feature" to grow your own live food. This is a good time of year to start one up, if you're so minded. Mine is a plastic tub that looks like a half barrel, and I stuck some sand and aquatic plants in there, plus the result of a few sweepings of the net in another pond. It now has daphnia, ostracods, freshwater amphipods, leeches, hydra, Tubifex worms, snails and all sorts of other small beasts. Many of these are useful and safe live foods for things like pufferfish and baby fish that are otherwise difficult to feed. Even if you don't have access to any real ponds, adding a couple bags of daphnia from the shops will get things started, and a lot of things, like insect larvae, will just arrive by themselves. I've even kept some tropical fish (peppered Corydoras) in there over summer, despite the lack of a filter. They not only did well, they bred as soon as I brought them indoors. So what I'm saying is that even if you don't have a pond, if you're finding keeping just the nymph fun, consider scaling things up to a "mini pond"! Cheers, Neale.>

FW Copepod? -- 05/16/07 Hi Bob, <Hello George!> Just found this beauty in one of my tanks and I was wondering if you know whether it is a parasitic copepod or not. Mind you, it was found in a freshwater tank. Thanks a lot for your help !! All the best, George J. Reclos <It does appear to be an aquatic Acarinan... not a Copepod, but might be deleterious... BobF>

Hi Bob, Thanks for your instant response. Do you know of any ways to get rid of it ? George <Mmm, yes. In the absence of other arthropod life, the use of an organophosphate like DTHP/Masoten/Trichlorfon... or Dimilin. Please read here re: http://www.wetwebmedia.com/PondSubWebIndex/contrpdparasit.htm BobF>
Bugs in tank 4/27/07 I have a 50 gallon tank that we fill to about 47 gallons because we have a fire-bellied toad. Recently, I have seen tons of extremely small darker colored bugs jumping along the surface and sitting on the tops of our lily pads. <These aren't bugs (i.e., not Hemiptera) but some other type of insect, most likely collembolans or some other very primitive, moisture-loving insect.> The problem is that they seem to really be bothering our toad because he tries to stay in the water most of the time now. <Sounds very unlikely. Collembolans eat decaying plant matter, and pose no threat to a toad. This is a case of two things happening at the same time, but not actually being related. Check water quality, humidity, whether they have enough land, scary things like loud noises, etc.> What can I do to get rid of these things so he will not be so miserable and what could they be. <You can't get rid of them any more than ridding your garden of ants. They're harmless so don't worry too much. If you truly have a plague of them, then consider what they're eating: if there's lots of food for them, they'll multiply; if the tank is kept clean, they will die off or move elsewhere to find food. You have populations of these collembolans all over the house, particularly the kitchen and bathrooms, where it is warm and damp. At night especially they "spring" about looking for new resources, and it sounds like your toad-arium has just what they want.> Any help would be greatly appreciated. Thanks, Kimberly Boling <Cheers, Neale>

Very Tiny Bugs on Water Surface 2/13/07 Hello, <Danielle> I have a 120G Amazonian community tank. It has been set up for about a year now and is doing well. I have noticed something curious when I do a water change: there are quite a few (30-50) tiny bugs that hop around on the surface of the water. <Neat> These bugs are very, very, very small (less than half a millimeter, I would guess), so small that I can barely see them and too small to photograph for you (I tried!) - and much too small for even my smallest fish to notice. I have attempted to catch one and look at it under my microscope, but have been unsuccessful. <Ahh, at least a "B" for trying> I only notice them during a water change when the surface is more than 2" below its full level, the water is still, and my four 65W compact fluorescents are on - I would not be able to see them otherwise. The bugs do not seem to be swimming or in the water column. They do not walk on the surface; they just hop (and hop quite high). <Some lessons in water tension now!> Their shape is that of a new-model VW Bug, flat on the bottom and a slightly slanted semi-circle on top. They have a distinct pair of antennae set at about 70 degrees from their body; one antenna is set at about 90 degrees to the other. At first I thought they might be dust mites, but dust mites do not have antennae. <Correct> They are much smaller than fleas (which do not have distinct antennae either). Have you noticed these in your tank(s)? What are they? Thank you, Danielle <There are a few groups of "water riding" insects other than the well-known striders (Hemiptera, Gerridae)... however... what you have here is likely juveniles of this family... do take a look-see re... These very likely "came in" with some of your plants... and will cause no harm. Bob Fenner> Sorry - in the third-to-last sentence, I meant "They are much smaller than fleas..", not "much bigger". Thank you! I greatly appreciate your efforts! Danielle <Ahh, will amend. Thank you, BobF>

Worms In The Aquarium/Flies In The House 1/8/07 Hello, I am a fan of your site and have always been able to figure out what was going on in my aquarium by looking at your pages but I'm now having an issue that I can't find any info on. I seem to have tiny worms growing in my aquarium, which eventually mature into tiny flies. Do Planaria do this? I don't think so. I have looked around on the web and cannot seem to find any info. A friend of mine has noticed white spots on her aquarium, which I would imagine to be Planaria, but she says she also has noticed tiny flies around her apartment. I do not have white spots in my aquarium and the worms themselves are not white, but more of a reddish brown colour. I have already begun daily water changes and gravel vacuuming as suggested for removing Planaria. I have also cut back feeding. Just wondering if any of you could offer any suggestions as to what these little creatures might be. I have actually witnessed the transformation from tiny worm, to tiny tadpolish thing to finally a tiny fly sitting on top of the water right before my very eyes. Any ideas would be appreciated. Thank you for your time. Amy < There are many insects that have an aquatic stage to their life cycle. They could have come in with the gravel, plants or the food. The aquatic stages can all be killed with Fluke-Tabs. This medication will kill all the invertebrates in the tank.-Chuck>

Oscar question... insects on light lid 12/29/06 Hi, <Greetings> My name is Nicole I ran across your site while searching for an answer for something going on in my Oscar tank. I have two Oscars, they are both around 7 inches, I've had them for several months. They are also in a 75 gallon tank with a bottom feeder. The past month I have been noticing little bugs on the light lid, inside of their tank. All of their levels are fine, I change their water weekly sometime bi-weekly. Both of them are healthy, they eat plenty they love each other. I just can't seem to figure out what are these bugs, how are they there, why are they there, and how to get rid of them. I don't want my fish to get sick. Please help me! ~Nicole M <Mmm, likely an "outside" insect... I would simply wipe these off with a damp, plain paper towel when you see them... They should "go" with such maintenance in a short period of time. Bob Fenner>

Fresh water - centipede 6/10/06 I've got 35 gallons of freshwater - only a few tetras while the tank is cycling. We had some major problems with a Molly (from a local pet store - ugh) and we're rebuilding our tank. I've got fake plants, no "live" rock - the substrate is a mix of aquarium rock and river rock (long ago cleaned, boiled, soaked in water for weeks on end, etc, etc, etc) Everything is settling down and looking good - then I notice this centipede in the middle of my fake plants. <!> I don't think it was a bristle worm - after looking at all the pics of both - it really didn't resemble a bristle worm, it looked exactly like a centipede (that and I've seen centipedes before...) <Likely some sort of insect larvae... does it have many legs?> It was about 1 1/2 inches long - curled up on the plants. Colors kind of orange and dark brown or black. When I pulled it out, it was still moving around, had the legs, head and tail of a centipede. Tossed him out and gave a good look through my tank - no sign of any other uninvited critter. <Good> So, where would this thing have come from? <Might have been "laid" there... fallen in, perhaps came as a juvenile in food..> And does it mean my tank is not ready for new fish? Help? <Shouldn't be a factor if removed, the system is cycled. Bob Fenner> Thanks! Rochelle

Freshwater Sea Monster, in Miniature - 04/05/2006 Hi Guys, <Sabrina today, not much guy-like, really> I have a freshwater tank, 175 litres of water, tropical setup. We recently purchased a new plant and discovered that I believe, is a bristle worm. <I.... don't think there *are* freshwater bristleworms. I could be wrong.> <<There are some FW polychaetes... not prominent, large, many... RMF>> I have attached two pictures to aid in identifying this little fella. I have read much on saltwater bristle worms but very little on fresh water ones. I know some worms are beneficial. However I wanted to make sure that this worm was not toxic to my fish (Platies and angels) as they did try to eat it. The brave little worm but up a fight and wiggled free, then I rescued him. I would not mind him staying in tank if I could be sure that he was not poisonous. <I've got no guarantee there, but I rather doubt that he is.> Also the worm is approximately 2 cm by 3-4mm. Any help in this matter would be appreciated. <This looks to me to be an insect larva of some sort - and very cool lookin' at that. Were it me, I'd keep him for sure. There is a minor possibility that, as he grows, he may become slightly predatory on very small fish (fry, etc.). I think he's just awesome enough to be willing to wager the minor risk!> Thanks Roni & Ruth (Geelong, Victoria, Australia) <Congrats on the very neat find! -Sabrina, in the Santa Cruz mountains of California, USA> <<RMF also sees these as insect larvae... may well be predatory.>>

Insect ID Hello, we don't know the name (scientific or common) of this insect and would like to do some research into exactly what it is. Do any of you WWM Crew know what the scientific or common name of this is so we can study up on it? We have never seen anything like it until we found this where we work. The head and front legs are bright yellow and the rest of it is dark purple. The tail is at least 4-5" long. I am sending a picture. Thanks for any help, Jeff <Nice pic. Does appear to be a species of Mud Dauber Wasp (Hymenoptera: Sphecidae). You can "look up" much info., other pix with these names on the Net. Bob Fenner>
Re: Insect ID Hello again, it is a wasp then with stinger as well? <Not necessarily> I assume the extremely long tail thing is not the stinger but is in the rear of the insect? <Yes> I entered the name you sent in your e-mail in ask Jeeves but am only coming up with pics of the common mud dauber that you mention and that I am familiar with. Any more clues that would point me to better pics with description on the web? Thanks ever so much again, Jeff <Do try Google... and words like "flying insect/s" and your State, general geographical area. Bob Fenner>

Not Mosquito larvae but what???????? are these things? I'm clueless. I inherited a 50 gal fresh water tank with Mollies, Gouramis, danios, tiger barbs and Corys. I've had it four years. I had no experience and fish have survived thru no fault of my own. Several months ago, fish store had water hyacinths. Being clueless, I bought one. Ended up with snails but learned they are a mixed blessing, can be controlled and no big deal. <Good> HOWEVER, the last few times I've done water changes, I noticed the water looks like it is snowing - hadn't seen anything like it before but attributed it to stirred up sediment. After the 2nd or 3rd time, it just looked too strange so I got a magnifying glass. Along with the normal gunk, I saw these things, about 1/8" to 1/4" long and there was one today that was 1/2". They look like white thread and snap around like mosquito larvae but they are not. With stronger magnification, it looks like they have razor scales along their body and some sort of head at one end. Does any one know what these critters are? Are they a problem for the fishes (and/or me since I've had my hands in there)? Thanks to who ever has info to share. <I hope these are just one of a few possible aquatic insect larvae that are harmless (look up the word "chironomid" on the Net with Google, look at images), and not small Odonatans/dragonflies... Here's a fave: http://insects.ummz.lsa.umich.edu:16080/~ethanbr/chiro/ Bob Fenner>

Re: chironomid-think you hit it THANK YOU for the help. Picture I saw looks exactly what I see in my tank with magnifying glass. <Ahh> I am ill right now so unable to read all the info, however skimming thru it learned they are used as bait by fishermen and thereby harmless? (Can't help wondering how they get those little things on a hook? <Yes, harmless. In fact, often used as fish food in places. Be well. Bob Fenner>

Chironomid-last thought and then 'over and out' Don't try eradication, let them be and save on fish food? <I would> Didn't know enough to think it germane mentioning 50 gal indoor led to 600 gal outdoor. <Hee hee, this happens> Plants I bought were grown outdoors and purchased for outdoor pool. Clueless me took a small one and put it in house tank which explains how this type critter got inside. <Also not uncommon... I've done this on (from the Old English meaning "many") several times...> Thanks again for helping me put the pieces together! <A pleasure to share. Bob Fenner>

Tiny jumping spiders Hi, I have a weird question. I have a 48 gallon tank with 8 cichlids in there. Tetratec300 power filter, all the water specs seem ok, but I noticed the fish seem very scared and stick close to the bottom, they rarely swim all the way up if at all. They do if they're really hungry and it seems they do it really quickly, meaning, they swim up quickly to pick up the food and swim back down quickly. Now the question is, I see some weird tiny white (clear?) spiders, they are maybe 1mm in length, hard to say whether they're spiders or something else but seeing one very up close I noticed it has about 8 legs. in the beginning I thought it was just air bubbles in the aquarium but now I'm beginning to think it's them! there's a couple dozen of them on the surface of the water and they seem to be jumping up and down! now if they "are" the bubbles in the aquarium, then I have hundreds of them!!! I turned the filter off for a little while to make sure it wasn't the water splashing and I was right, it's tiny little white thingies jumping around!!! How do I get rid of this, I do partial water changes every week but I guess that didn't do anything... help me!!! < These are little springtails and are harmless to the fish. They feed off the fish food when you feed the fish. If you decide to switch to a wet dry filter with a surface skimmer then they will be sucked into the skimmer.-Chuck>

Small black flies Hi, I have a 55 gallon tank with only a few fish in it. About 2 months ago, I started seeing these little worms in the filter when I changed it. Then I started seeing these small black flies all around my fish tank. They were coming out of the filters! What is this and how do I get rid of it? < Usually invertebrates are quickly eaten by fish. If you obtained any sand, rocks or plants from nearby waterways then the contaminants could have come from these sources. Clean your filter often, change 30% of the water weekly and do not overfeed your fish. A clean aquarium will usually take care of most of these little critters. If you want to medicate the yank then try Parasite-Clear or Fluke Tabs.-Chuck>

Gnats in the Aquarium, Mystery Answerer? I am writing you for my mom, She is having a whole lot of trouble with gnats in her fish tank and it is driving her crazy, she cleans her tank and even changes the gravel very often, and nothing seems to work. She loves her fish but she says if she can't get rid of the gnats she will have to get rid of the fish and that is the last thing she wants to do. She has 3 cichlids in her 29 gallon tank, she has tried parasite tablets and that hasn't worked either. Can you help? Thanks, Rachel Please reply ASAP. < Insects in the aquarium are pretty rare. I don't thinks the gnats actually come from the aquarium because I don't think they have a larval stage and cichlids are pretty good at eating any sort of insect life. If any insect/snail or worm are found in an aquarium then Fluke-Tabs will get rid of them. >

Larvae 9/30/05 Hello again, Everything is going well with my tanks and my Oscars, but today I found small black wormlike larvae (it looks like) at the top of my filter cartridges, they are at the edge of the water not really down in the water. Can you tell me if these are harmful and if there is anything I can do with them. I changed the cartridges, although they weren't that dirty. They didn't seem to be anywhere else as of now. Thanks for your time. J <Likely not harmful... and very possibly of terrestrial (out of the tank) origin... some insect reproducing... I would do as you have done and just rinse, clean your cartridges and remove them. Bob Fenner> Hello again, I just wrote to you about the little black worm like things and I just noticed some in the substrate so I guess they are in the water. anyhow, can't wait to hear what this is. J <Mmm, again, I would siphon these out and not be overly concerned. No matter what their origin, it is highly unlikely they are dangerous to your Oscars. Bob Fenner>

Strange Bugs In The Tank 12/1/05 I just cleaned my fish tank and noticed these little silver-ish color worm type things. I have also noticed little flying bugs by my lights. Anyways I caught like five and put them in a container with a lid. I opened it a hour later and there was two of the flying bugs in there what are they and how do I get rid of them. Thanks Lindsay < There may be a correlation between the two. The lights may be attracting the insects that lay eggs in the water and hatch into the wormlike creatures you are now seeing. Normally I think the fish would eat these. Add Fluke -Tabs to the water and that will kill any invertebrates and insect larvae and hopefully both problems will go away.-Chuck>

I know you've heard the phrase "tiny bugs" a million times... - 03/09/2006 But I have "tiny bugs" with oval-shaped bodies and a circular head (*maybe* 1mm in length and 1/3mm wide - at the most!) that are either brown or black in color, have 6 (maybe 8) legs and 2 antennae (I only know because I got out a magnifying glass), and they can't swim but they love to be on the sides of the tank above the water and to bask in the light under the hood and on my breeding net. <A great description - and could be many different things. If there are any floating plants, or plants that break the surface of the water even a bit, involved, I might guess that these could be Aphids. Lots of possibilities, though.> They don't look like insect larvae, though. I have a 10 gallon FW tank with 5 adult guppies, a Pleco, 40-some guppy fry that are only a few days old, and some small brown snails (I don't know what species of snail, but I don't really care much either as long as they behave). <Heh, they won't, but that's probably okay. Do be cautious about letting them stick around.> At first I thought they were baby snails as my snails have laid eggs, but they crawl too fast and after using the magnifying glass and my knowledge that snails don't have legs, <I certainly hope not!> I realized they were not in fact the cute baby snails I thought they were. My question is what these bugs are <Tough one> and how I can get rid of them. <Not quite so tough.> I read pages of FAQ's on the website and you mentioned Parasite-Clear and Fluke Tabs, but would either of these work on insects that aren't IN the water, <Highly unlikely.> or could either of them harm the fry? <Yes, quite possibly. I would not risk it. These little buggies are likely of no threat to your fish or tank. They're feasting on something (flake food particles stuck to the sides of the tank, plants, or something else) that is keeping the population sustained. If you can isolate whatever it is that they are feeding on and reduce or eliminate it, you will be able to reduce or eliminate the buggies. Um, you could also try rinsing or wiping them into the water as munchies for your guppies.> Thank you for your time!! <You bet!> -Jessica, South Dakota <Wishing you well, -Sabrina, of the Santa Cruz mountains in California.>

Little Bugs At the Top of The Water 7/28/06 Hello I have a 55-gallon community tank w/all plastic plants, angels, a Pleco, clown loaches, and a few other community fish. Today I was doing a water change and noticed tiny brown bugs crawling around on my artificial lily pads. I checked and saw them jumping around on the surface of the water. There are quite a few of them, but I never would have noticed them because they are so small that I cannot make out their appearance. Do you have any idea what they are, are they harmful, Should I get rid of them and how? Thank you. Ben Berube < These little springtails are completely harmless and usually come in with plants or fish. They feed on the little bits of leftover food.-Chuck>

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