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FAQs on Neon Tetra Behavior

Related Articles: Cardinal Tetras; A School of Beauty, Part II,  by Alesia Benedict, Neons, Cardinals & Their Kin; Selection, Maintenance & Healthcare by Neale Monks Characid Fishes

FAQs on: Neon Tetras 1, Neon Tetras 2,
FAQs on: Neon Tetras Identification, Neon Tetras Compatibility, Neon Tetras Stocking/Selection, Neon Tetras Systems, Neon Tetras Feeding, Neon Tetras Disease, Neon Tetras Reproduction/Breeding,

Related FAQs:  Cardinal Tetras, Characid/Tetra Fishes,


Spinning neon tetra     12/3/13
Hi there
One of my neon tetras has had an issue swimming - first it had a problem staying horizontal and swam more vertically upwards but now it sinks and spins when it tries to swim.  It also has a little lump on its tail.  Any ideas?
all the best
<Could be a few things... Myxosoma most dramatically. I would have you read here: http://wetwebmedia.com/FWSubWebIndex/NeonTetDis.htm
Bob Fenner>

Is it bad if my neon tetras (4) lose their neon color?   1/10/12
Not completely, but its not as bright as it used to be and only one of the four is. Could that mean he is sick, or is it just because I switched food types?
<Yes, it can be bad. Neons lose their colours at night, but switch them back on when the lights come on. If the colours stay "off", then there's a good chance the fish are stressed or sick. Neon Tetra Disease is a common problem. Cheap Neon tetras are particularly prone, as are Neons kept in hard, alkaline water. Cheers, Neale.>

Hiding Neon Tetra  6/8/10
I have a 25 gallon tank (fully planted and cycled). It currently homes 5 neon guppies (1 male, 4 female), 5 panda Platies (1 male, 4 females), 3 cherry shrimps and 9 neon tetra (new). You have previously informed me that I was misguided by the aquatic shop about the tetras being ok in a tank with a high water hardness (London water).
I've had the tetra about a week now and I have noticed that one now hides in the corner at the bottom of the tank under the plantation and rarely comes out. Is it normal?
<Perhaps. May be bullied, but hiding is also an early symptom of Neon Tetra Disease, an epidemic among farmed Neons.>
All ammonia, nitrite and nitrate levels are normal/safe.
<Unfortunately Neon Tetra Disease is very common, and it is also highly contagious. There's no cure. Infected fish become shy, lose their colour, don't feed, swell up, and eventually die. Possibly infected fish should be isolated in a hospital tank and extreme precautions taken to make sure water doesn't mix with the water in the main tank, e.g., by sterilising nets and buckets. If the suspected fish develops further symptoms of NTD, it should be euthanised; see WWM for more on this.>
Many thanks, Patrick
<Cheers, Neale.>

Largest Neon ever? - 1/24/08 Dear Web guys, Thank you for you assistance with prior questions when I was starting my fish hobby a year ago. One I have not found the answer to (yet) is what the record size is of the largest ever neon tetra? I have one who is larger than some of my mollies, so he's certainly in the running. My search on Guinness Book of Records thus far has failed to reveal an answer. Thanks! Tambra <Hi Tambra. Neons -- Paracheirodon innesi -- can reach 4 cm in length, though that's pretty rare. Cardinal tetras -- Paracheirodon axelrodi -- do get a bit bigger and are a bit stockier as well. The two species are easy to confuse, but Neons only have red running halfway along the body, whereas Cardinals have the red band running all the way from the tail to the snout. Anyway, if you have a Neon bigger than 4 cm, I'd love to see a photo! Cheers, Neale.> Re: Largest Neon ever?  1/25/08 Hi Neale- I will try to get a picture with my camera phone later (will need to borrow a digital camera for high quality) She has outlived many Neons, and I'm sure that's what she is. <Cool. Maybe we're witnessing Evolution in Action! Hurrah! Look forward to seeing the pictures. Cheers, Neale.>

Tetra buoyancy  10/20/07 Dear Crew, <Hello there! Andrea with you this afternoon.> Today after feeding my Tetras I noticed that 1 of my Neons is floating toward the surface and actively swimming to stay lower in the aquarium. I feed them tropical flake food with the occasional freeze-dried bloodworms. <Sounds delicious...> I hadn't noticed this behavior before today so my theory is that he sucked in some air while eating. My water parameters are as follows: Ammonia, Nitrite and Nitrate all 0, pH 7.8. <pH is a little on the high side for Neons, but I wouldn't worry much. You might add some driftwood as a decoration to the aquarium to soften the water and bring it down. What does concern me is that the NitrAte is at 0. How long has the aquarium been up? Generally speaking, in the FW world, we want to see a little nitrate, as it lets us know that the tank isn't cycling. You should have something of a reading...5, 10, 15 ppm at least. What kind of test kits are you using? You might take a sample to the local fish store and have them test it. Having zeros across the board usually tells me that either the tank is brand spanking new, or the test kits have gone bad.> I do a 40% water change every 5 days. <Excellent regimen. Keep it up!> I don't feel that it is a water quality issue, he's not listing around or floating head up or down, but when he stops swimming he floats to the surface. <Could be swim bladder dysfunction. It's not fatal, just looks funny. Do a search on WWM for Swim Bladder for more information.> Is there anything I can do or is this just a "wait and see" type of thing? <If he is otherwise acting healthy, stool looks normal, eating well, I'd just let him be. Could be needing a good burp, could be the food is too fibrous, could be swim bladder, could be something else. You might also try giving him some mushed up blanched peas, in case he has a mild case of constipation.> If it is air and he can't expel it, is that a fatal condition? <No, the air will find a way out, one way or another ;-). They are kind of like us in that way.> Also, how long could it take for him to recover from this? <It really depends what it is. If it is swim bladder damage, he might always be that way, and it is just a quirk. If it is something else, it may pass, or it may not. Worst case scenario is he has some problem that is affecting him neurologically, such as a bacterial infection or parasite, but I'd say the chances of that are relatively slim if he is eating and otherwise well. Unless he shows other symptoms, I'd just call him "Bobby" or "Floaty" or "Bouncy" or something cute.> Thanks for your help, <Anytime!> Evan <Andrea>
Re: Tetra buoyancy 10/29/07
Andrea, et al: <Hi Evan, sorry for the delay. I have been out of town.> Thank you for your help earlier. <Most welcome.> I wanted to update you on the situation. After about 5 hours "Bob" seems to be back to normal. <Glad to hear it.> I've only been keeping fish for 3 months, so when I saw his behavior I was surprised and alarmed. <It happens to all of us. I've been keeping fish for years and years, and still panic often. The same with my cats, frogs, lizards, toads, nieces, nephews....call it human care instinct. =). It does ease up a bit though.> And on the water tests: I'm using Jungle 5-in-1 and Ammonia quick dip tests so the readings aren't super precise and some of the tests have a large gap between values. On the Nitrate the scale is 0 then 20 and it was definitely not 20. <The test strips are good for getting a general feel of water conditions, but since you are new to the hobby, I really suggest you get better test kits, with liquid reagents. They really are an invaluable tool, especially early in the hobby when you are just learning. The accuracy will help you both learn and get a better feel for the conditions in your tank. API makes good kits for freshwater that are reasonably priced and readily available. You will want to have Ammonia, NitrIte, NitrAte, pH, kH, and possibly Phosphate on hand. Salifert are also excellent, but more expensive. It will serve you and your fish well to buy these and familiarize yourself with them and their properties.> Again, thank you all for your continuing help to all of us fish keeping novices and experts. <Our pleasure.> -Evan

Dull Neons... Hi there, I was wondering if you could give me some advice on my neon tetras. Today I noticed that they are looking very dull in colour and not swimming about as much as they usually do, also one of them is bloated. I thought this could be neon tetra disease, do you think this is the case? If so, should I carry out euthanasia? < If the disease is only affecting one fish then I would get rid of it. If it looks like it is going to spread to the other fish then I would treat with Nitrofuranace of Myacin. Make sure you follow the directions on the package.-Chuck> Thanks Fran

Getting Neons to School (drive them there?) Hi, <Hello> I have a 75 gallon tank with about 18 neon tetras and am planning on getting another half dozen or so.  Currently, I also have 4 peacock gudgeons and am planning on getting a few rams and maybe Apistos. <Sounds like a very nice assortment> My problem is that my Neons are not schooling, at least they don't form really tight looking school.  I have a moderately well plastic planted tank and I think the Neons just feel pretty safe in the tank.  Can you recommend any easy to care for fish that would scare the Neons into schooling. <Mmm, not scare... I suspect some aspect of water quality is at play here... what's your water chemistry, temperature?> Not something that would eat them, but just something to make the neighborhood seem tough enough to rekindle their schooling instincts.  I've thought about discus, but only want to do at most 5 gallon water changes each week.  Any suggestions? Thanks. Nate Terry <Raise the water temperature to the mid 80's F... check that the water is not too hard... Bob Fenner>

STUPID NEON TETRA? I have 5 zebra Danio 5 neon tetra 2 Cherrie barbs and a Bloodfin tetra in a 10 gal. tank. But the one neon tetra stays with the female Cherry barb and darts through the school its supposed to be in breaking it up and returns to the female. Is this normal or is it just stupid. This has been occurring for 2 days now so please help. < Normally fish school together for protection. It could be that their is a dominant male tetra in the school chasing away a rival male. The rival male does not want to be left out because in the wild that usually means it will soon be somebody's lunch very soon. So it has probably tried to school with any fish that will tolerate it while trying to break up the other males happy harem.-chuck>

Going To School Will cardinal tetras school with neon tetras?  What other types of tetras will school with Neons? <Well- as far as schooling "with" the Neons, any tetras of similar size could join up. However, I have seen Neons school with Cardinal Tetras, Glowlight Tetras, and even Rasboras on a few occasions, so anything is possible. Usually, in my experience, anyways, the Neons seem to school with Neons, Glowlights with Glowlights, etc. Keep an eye on these little guys- their behavior is very interesting! Enjoy! Scott F.>

Nasty Neons Hey! I just wanted to say that I have learned a TON of information from your site. I have looked throughout your search for an answer to what I'm observing, but haven't found one yet. So here is my question. I have a ten gallon tank up and running that is around two and a half months old. It is my first tank and after setting it up and having some fish die, I learned about cycling. So after a few dead fish and a ton of money spent on testing kits, I think everything is going okay. There are 5 guppies (2 m. 3 f.) and 4 Neons. I tested the water today and these are the stats: ammonia: 0 Nitrite: 0 Nitrate: around 20 (the test is a colored water thing that is sometimes hard to get exact numbers from) Temp: 79 (it's getting hot in California!) Ph: 8 (we have hard tap water) Regarding the Neons, I have one that is noticeably smaller than the other three, but he is really aggressive. He (I'm guessing) doesn't school, but isn't hanging at the bottom or hiding. He hangs out right in the middle of the tank and chases the other Neons away. I'm wondering if this is something I should be worried about. I know that Neons do better in larger numbers (6+?) but I don't want to add more fish and throw this little tanks' levels out of whack. Could I add two more Neons and be okay? Thanks for any help you guys can provide! You all do the aquatic hobby world a great service! -Shannon <Sure. As long as you watch the nitrate and adjust your water change schedule to keep it below 20ppm you'll be fine adding three or four more Neons. It's also a good move to control the aggressive one. If you're goal is breeding the guppies you will need a fry tank. Neons are small, but they can take newborn guppies. And any that make it would start to overstock your tank. Don>

New tank, fat Neons Hi there, <Good morning!> I'm 13 and I love fish. I saved all my money and got a 30litre tank. I have done everything right washed the gravel and planted plants and o on. I left it running for a week and have done regular pH level tests. 2 weeks ago I got my first 4 fish, 1 peppered Cory and 3 neon tetra. All is well, until today when I noticed that the largest and 2nd largest of my neon's have very large stomachs!! I am not quite sure what it is , I am thinking pregnant because those 2 seem to spend a lot of time together but I began to wonder if maybe it wasn't so in a panic I searched and this sight looked really useful so here I am!! Do you think you could help me, will it spread to my new ???'s they are half orange and half deep blue, small, smaller than the Neons!! <Mmm, I suspect your "fat" Neons have just eaten a good deal more dried food than they should have... and will thin down (or have done so already) on their own. Do look into using other types of foods (frozen/defrosted, fresh) to keep

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