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FAQs on Fishes called Chocolate, Brown Knifes

Related Articles: New World Knifefishes, GymnarchusNotopterids/Clown KnifefishesBlack Ghost Knife, Electrogenic Fishes

Related FAQs:  Knifefishes 1, Knifefishes 2, Knifefish Identification, Knifefish Behavior, Knifefish Compatibility, Knifefish Selection, Knifefish Systems, Knifefish Feeding, Knifefish Disease, Knifefish Reproduction, Electrogenic Fishes, & by Group: Aba Aba KnivesElectric Eels (Knives), Glass Knifefishes, (Eigenmannia), Gymnotus carapo, Notopterid Knifefishes (Clowns...),

Electric fish questions      6/9/16
Hello! Thank you for your past advice in caring for my Brown Ghost Knifefish (Apteronotus leptorhynchus), that has been immensely helpful!
I've had my little guy (or girl, as the case may be) for about 10 weeks now and is doing well. He has gained weight and I believe he has grown longer as well. At least, he is having a harder time fitting into his favorite daytime hiding place. There is always a bit of his tail sticking out, LOL. I got one of those clear acrylic tubes that they sell for Ghost
Knifefish (A. albifrons) but he never uses it. I got the "Large" size so it's plenty big enough for him. At first I thought he didn't like it because it is clear but I read that this doesn't make a difference because their electrical senses tell them that they are in an enclosed space. The tube is near his favored hiding place. I wonder, is this maybe a difference between A. albifrons and A. leptorhynchus?
<Mmm; well both will use such tubes or not>
Or could it be that the tube is just a little too big for his current size?
<Or that it/these don't have much/enough conductivity?>
Besides the tube there are several possible hiding places in amongst the driftwood and rocks but he consistently chooses a very tightly fitting space.
<Ah, good>
An interesting behavioral note: The Brown Ghost has only been in his permanent home for about 6 weeks (after 4 weeks of quarantine) and he is still very very shy.
<This is their nature. Rarely do Apteronotids become "out and about" community fishes>
I have never seen him out and about during the daytime and even at night he seems to mainly stay in hiding. But at night, if I come to the tank and look at him he will venture towards me partway out of hiding. Maybe he is anticipating being fed?
<Yes; and this is when they do forage in the wild>
The other fish in the tank get fed during the day of course, but feeding time for him is always about an hour after lights out.
Ok, question about a different fish now. A few weeks ago I saw a Peter's elephantnose fish in the local petstore, he had been an owner surrender.
The poor thing was miserable in a small tank with many other fish, and he had a damaged "trunk" so of course I took him home with me. Either he got bitten or else damaged against a rock or something, but most of his trunk is gone now. He seems to be settling in but I am wondering how good his chances are without his trunk?
<Have seen Mormyrids live long, seemingly happy lives without>
Will he be able to find food effectively without it?
<Yes; likely so>
He also stays in hiding most of the time which is understandable given the trauma he has been through. The injury seems to be healing up cleanly with no signs of fungus or infection. Please understand, I would have still bought him even if I knew his chances were not good as he is at least a bit more comfortable now (i.e., not in a very small tank with too many other fish and no good place to hide). But I do hope he will be able to adapt and get better. What is your opinion on his chances?
<Good in your care>
Thank you for being such a great resource, especially for those of us who love the more unusual fish!
Joanne
<Welcome. Bob Fenner>
Electric fish questions /Neale      6/11/16

Hello! Thank you for your past advice in caring for my Brown Ghost Knifefish (Apteronotus leptorhynchus), that has been immensely helpful!
<Most welcome.>
I've had my little guy (or girl, as the case may be) for about 10 weeks now and is doing well.
<Cool.>
He has gained weight and I believe he has grown longer as well.
<Excellent. But do bear in mind this isn't too difficult to achieve when they're small; it's the medium to large specimens that pose the biggest challenges.>
At least, he is having a harder time fitting into his favorite daytime hiding place. There is always a bit of his tail sticking out, LOL. I got one of those clear acrylic tubes that they sell for Ghost Knifefish (A. albifrons) but he never uses it.
<Many don't. But do try moving it to other spots. For example, close to a heater or filter there may be an electric field they find irritating, a bit like having a bedroom by a noisy street. Try moving the tube to other spots in the tank.>
I got the "Large" size so it's plenty big enough for him. At first I thought he didn't like it because it is clear but I read that this doesn't make a difference because their electrical senses tell them that they are in an enclosed space.
<Something like that, but they actively avoid bright light, so a clear tube needs to be somewhere shady, for example against the left or right hand side of the tank, covered up with plants or rocks. You can peer in easily, but the fish feels like he's hidden.>
The tube is near his favored hiding place. I wonder, is this maybe a difference between A. albifrons and A. leptorhynchus?
<Conceivably. But bear in mind these fish all tend to come from tannin-stained, deep or shady areas. That's why they use an electric sense -- eyes aren't much use.>
Or could it be that the tube is just a little too big for his current size?
Besides the tube there are several possible hiding places in amongst the driftwood and rocks but he consistently chooses a very tightly fitting space.
<Quite so.>
An interesting behavioral note: The Brown Ghost has only been in his permanent home for about 6 weeks (after 4 weeks of quarantine) and he is still very very shy. I have never seen him out and about during the daytime and even at night he seems to mainly stay in hiding. But at night, if I come to the tank and look at him he will venture towards me partway out of hiding. Maybe he is anticipating being fed? The other fish in the tank get fed during the day of course, but feeding time for him is always about an hour after lights out.
<Agreed. By all accounts electric fish are "smart", and at least some fish are unique in demonstrating what's called "play behaviour", something otherwise considered unique to mammals and birds. Body weight to brain size is also a lot closer to a mammal or bird than it is to your average fish. So absolutely, a certain amount of learning is entirely possible, even
likely when they're kept right.>
Ok, question about a different fish now. A few weeks ago I saw a Peter's elephantnose fish in the local petstore, he had been an owner surrender.
The poor thing was miserable in a small tank with many other fish, and he had a damaged "trunk" so of course I took him home with me. Either he got bitten or else damaged against a rock or something, but most of his trunk is gone now. He seems to be settling in but I am wondering how good his chances are without his trunk?
<Can grow back, though usually remains a bit stubby compared to the full sized organ.>
Will he be able to find food effectively without it?
<It's harder for sure, but not impossible. They have other senses, including an electric sense, and their sense of smell isn't limited to the trunk but is also provided by the usual array of nostrils and sensory pits seen on other fish.>
He also stays in hiding most of the time which is understandable given the trauma he has been through.
<Yes.>
The injury seems to be healing up cleanly with no signs of fungus or infection.
<Good news.>
Please understand, I would have still bought him even if I knew his chances were not good as he is at least a bit more comfortable now (i.e., not in a very small tank with too many other fish and no good place to hide). But I do hope he will be able to adapt and get better. What is your opinion on his chances?
<Once he starts eating, I'd be very positive. I've seen these fish go bonkers feeding on live brine shrimp nauplii in busy tanks during the daytime. So they're perfectly able to learn to adapt to aquarium conditions. But while you're settling this one in, do be gentle, and do offer a good range of healthy foods, ideally with the lights out.>
Thank you for being such a great resource, especially for those of us who love the more unusual fish!
Joanne
<Most welcome. Neale.>
Brown Ghost (A. leptorhynchus) update!      6/24/16

Hello! Since I have bombarded you guys with questions about my Brown ghost knife the past few months, I thought I'd give you a quick update. He was in a different hiding place this morning so I was able to get a good look at him. Wow! He has definitely grown longer over the past two months and has actually gotten a bit plump. I guess that means he has adjusted to his new life and is doing well.
<Certainly does. But the trick with Apteronotus is to keep aquarium size and filtration scaling upwards as the fish grows. Recall that volume is a cube of length. So if a fish doubles in length, it will actually be 8 times bigger in terms of bulk. For sure it probably doesn't require exactly eight times as much space or filtration, but it will certainly need a lot more space. Problems with Apteronotus usually happen when people get complacent.
The fish grows and all seems well. But as it grows it's becoming more demanding, and if you don't make allowances for that, sooner or later things suddenly go wrong. Make sense?>
He was in the hollow log shelter and facing the front of the tank. When I would look at him, he would swim forward a little, then back up. If I was out of his view, he seemed to just stay still so I'm pretty sure he was reacting to being observed, maybe hoping for some food to follow. So I'm going to do a little experiment with some target feeding to see if he will become a little more outgoing. You know, the way you would with a shy dog or cat... throw a little treat into their "comfort zone", once the treat is eaten throw another treat just a little closer to you, etc etc until they are comfortable coming up to you for the treat. Betcha this will work!
<Agreed; these are intelligent fish, meaning they're both sensitive to things that scare them, but also ready to learn as well.>
Oh yes, I keep saying "he" but I'm starting to think it is a female due to the length and shape of the face. I'm not sure how big they need to be for this to be accurate though. What do you think? At a guess, my fish is about 6 or 7 inches long right now.
<I'd be wary about sexing a fish before it's, say, half adult length.>
Thanks again!
Joanne
<Most welcome and well done. Neale.>

Brown Ghost Knife Fish care      5/10/16
Hello! First of all, thank you so much for the information you have provided me for caring for my Brown Ghost knife fish (Apteronotus leptorhynchus). It has been invaluable! Of course I still have questions though (smile). There's quite a lot of info regarding the larger A. albifrons, not as much about A. leptorhynchus. I'm sure most of the information applies equally to the Brown Ghost but there is quite a size difference between the two. Are the feeding guidelines for the Brown Ghost pretty much the same?
<Yes>
Are live ghost shrimp an acceptable food?
<Mmm; not unless they're very small individuals>
I've been giving my fish live blackworms, frozen bloodworms, and various frozen (meaty) foods. It would be nice to keep some ghost shrimp in there as an occasional snack.
<Worth trying... they may help to keep the system cleaned up as well>
And if the shrimp are a bit large for eating directly, well, they will have babies that can be eaten - at least that is my way of thinking about it.
<Ah yes>
After a month in quarantine I have moved my Brown Ghost fish into a 40 gallon breeder tank. It is heavily planted with a soil substrate topped with soft black sand. There are several large pieces of driftwood that provide hiding places as well as several branchy pieces of wood. There is also a ceramic "hollow log" that he sometimes uses as a shelter. There are
also floating plants galore. Tankmates are 5 marble Hatchetfish, 5 lemon tetras, and 7 neon tetras. I'd like to add a pair of Starlight Plecos (L183 Ancistrus dolichopterus) - would these be ok or would a group of Otocinclus be a better choice?
<I think either would be fine. Otocinclus are more active, but not as hardy>
There are no catfish or loaches in the tank, no other nocturnal fish to compete with the Brown Ghost at feeding time. I understand that Brown Ghost knife fish like to stay near the bottom of the tank so it seems that the top and mid water fish keep out of his space. But I wasn't sure about the Plecos, especially since this species also likes to eat meaty foods.
For water circulation, there is a hob Aquaclear 50 filter and a powerhead. The powerhead is located fairly low in the back corner of the tank, angled pointing up and toward the front to create a circular type flow. I'm not sure the gph for the powerhead but it is one I used to use for a nano reef tank and it really moves the water in a 40 gallon tank. Temperature is set to 76 F. I'm in the process of converting the tank to blackwater as it is the natural habitat of the fish in this tank.
<Sounds good>
My Brown Ghost is currently approximately 6 inches long. So far I have not personally witnessed him feeding but his body weight seems good and I believe he is a little plumper than when he first came in. He is still very very shy and of course moving to his new tank is another adjustment he must go through. I've seen YouTube videos of Brown Ghost knife fish that were pretty outgoing, swimming around in the open, etc. but have no idea how long it took to get to that point. Do these fish generally become more outgoing as they settle in?
<Yes they do>
Anything else I can do to help him feel more comfortable?
<Not as far as I'm aware. Have studied Apteronotids, been involved in their import, husbandry... they are tough, intelligent animals of much interesting behavior when well-kept>
Thanks again for your help and advice!
Joanne
<Welcome; Bob Fenner>

Re: Brown Ghost Knife Fish and Blackwater / Soft water       5/5/16
Thanks for the advice. I'll leave out the shells as the regular water changes should do the trick.
<Good>
The key should be fairly little but often to keep the water parameters steady.
<Agreed. BobF>
Brown Ghost Knife Fish and Blackwater / Soft water /Neale      5/5/16

Hello all! As always, thank you so much for your help and support! Got a question today for you.
<Fire away.>
After doing my research, I recently purchased a Brown ghost knife fish (Apteronotus leptorhynchus).
<Nice fish. Care identical to that of the Black Ghost, though it does seem to be a bit smaller; Fishbase reports ~26 cm (~10 inches) maximum length.>
He is still in quarantine tank and will be there until I finish completing his permanent (and much larger) home. From the information I was able to find about these (most of it from your website - thanks!) it seems these fish are quite prone to skin fungus.
<Sort of. Apteronotus Knifefish generally are sensitive across the board.
Not sure this species is especially delicate, given the dismal survival record for the standard Black Ghost, Apteronotus albifrons.>
Judging by their native habitat, they need to be kept in blackwater and/or soft water for optimum health.
<Helpful, but by no means essential. Avoid liquid rock if possible, but water quality, temperature, circulation rate and oxygenation are all more important.>
I believe keeping brown ghost knife fish in these conditions will help prevent fungal problems.
<Acidic water does inhibit bacterial infections, yes; whether they inhibit fungal infections I cannot say.>
My question is, which do you think more important - having blackwater, or having soft water?
<Soft, slightly acidic conditions are good. But VERY acidic water poses problems, for example biological filtration operates poorly below pH 6. But something like 1-10 degrees dH hardness, pH 6-7 won't be at all problematic if other parameters are favourable.>
Ideally both, but soft acidic conditions can be unstable and stability is also very important for these guys.
<Yes, but especially water quality. Zero ammonia and nitrite; minimal nitrate; lots of oxygen.>
It would seem logical that that tannins in blackwater would have an important protective effect for their skin.
<Logical perhaps but not sure it's as simple as this. The bottom line seems to be few bacteria prosper at low pHs, and fish evolved for really acidic conditions lack the anti-bacteria abilities of standard fish. Or so, that's what people say. You're absolutely right that many true blackwater fish -- such as Chocolate Gouramis -- are very disease-prone in hard water with an alkaline pH.>
So, I was thinking about setting up the tank with blackwater but including a few seashells or pieces of limestone to prevent the water from becoming too soft.
<Pointless; defeats the object of the exercise. If you go "blackwater", you need to rely on low (very low!) stocking density alongside frequent water changes to minimise pH changes. Sometimes you can use Discus Buffer, but that depends on your desired pH.>
Hopefully this would give the benefits of blackwater without the instability that can come with very soft and acidic water. According to my county's website, the water hardness of our finished water "averages 64 milligrams per liter, or about 4 grains per gallon."
<I have no idea what that means!>
What do you think about my plan?
<See above.>
Thank you!
Joanne
<Welcome, Neale.> 

Brown ghost knife; hlth.     10/25/13
Hi. I recently rescued a brown ghost knife from deplorable conditions. She had her tail eaten off, her fin was fringed, and she was covered in ick.
The people who had her had her in a ten gallon tank with two black ghost knives that were way bigger and relentlessly attacking her.
<Not social species>
I brought her home and I put her into a five gallon plastic portable aquarium and proceeded to change the water constantly for the next few days. By about a day and a half in she was showing no signs of ick anymore.
And she was pretty active. I moved her into a ten gallon ( she is tiny by the way, not even three inches) with a few caves and plants and lots of bubbles cus she seems to really like them. And she is doing really good.
She no longer looks emaciated and her color is great. She eats like a champ. So all that is great. I guess my question is how can I make her more comfortable?
<Need to know; or alternatively send you to WWM, the Net, books, re water quality here... Should be soft, acidic and warm...>
She never comes out of her cave.
<... are nocturnal>
Do you think some small innocuous dither fish would help her feel more safe?
<Possibly>
Any suggestions would be greatly appreciated.
<Do review what we have archived, and send along info. re the set up, test results for the water... Needs larger quarters in time.... Bob Fenner<>
Re: Brown ghost knife    10/25/13

Yes this set up is only temporary while I nurse her to full health so I can keep an eye on her.
My ph is 7.8
Am 0
Ni 0
Na .05
<... the pH is a bit high>

Yes I know that these guys are nocturnal, I keep a black ghost knife and while they are very similar they are also very different.
<Ahh!>
She pokes her head out when I talk to her and does her knife wiggle that they do.
<Sensing the environment... via electromagnetic sending, reception>
And I see her occasionally zipping around the tank at night when there is nobody in the room and the lights are off. But If she notices anyone is even watching she is gone lol.  I just want to make her as comfortable as possible. Thanks you for your feedback.
<And you for sharing. BobF>
Brown ghost knife...  Neale's go      10/27/13

Hi. I recently rescued a brown ghost knife from deplorable conditions. She had her tail eaten off, her fin was fringed, and she was covered in ick.
The people who had her had her in a ten gallon tank with two black ghost knives that were way bigger and relentlessly attacking her.
<Yikes!>
I brought her home and I put her into a five gallon plastic portable aquarium and proceeded to change the water constantly for the next few days. By about a day and a half in she was showing no signs of ick anymore.
<Good.>
And she was pretty active. I moved her into a ten gallon (she is tiny by the way, not even three inches) with a few caves and plants and lots of bubbles cus she seems to really like them.
<Indeed; these fish are somewhat oxygen-sensitive, and do appreciate brisk currents at all levels of the tank, not just at the top by the filter outlet, so adding extra aeration can be a plus by moving water from the bottom layer of the tank upwards.>
And she is doing really good. She no longer looks emaciated and her color is great. She eats like a champ. So all that is great. I guess my question is how can I make her more comfortable?
<Spacious tank, moderate temperature (24-25 C/75-77 F), excellent water quality, and turnover rates of 8-10 times the volume of the tank per hour, minimum. Water chemistry on the other hand isn't a big deal provided the water isn't too hard, and diet isn't usually a problem either as these fish accept frozen foods readily and often learn to take flake and pellets without complaint (in my experience, Hikari Cichlid Gold pellets work well with these and most other oddball fish, despite the "cichlid" name).>
She never comes out of her cave.
<S/he is nocturnal, so some degree of reticence is normal, especially given prior experiences. Plus, Brown Ghosts aren't as "upwardly mobile" as Black Ghosts, and tend to be shyer and less ready to swim to the top of the tank.
Do try installing some floating plants -- these are very good and providing shade and this in turn encourages shy fish into the open.>
Do you think some small innocuous dither fish would help her feel more safe?
<Conceivably, but I wouldn't put any money on it, at least, not without floating plants or some other way of dimming the overhead light.
Furthermore, adding fish will make water quality management more difficult, so balance any such experiments carefully.>
Any suggestions would be greatly appreciated.
<Hope this helps, Neale.>
Re: Brown ghost knife      10/28/13

Thank you so much for your reply. I have the entire tank covered with water lettuce and the only light is a dim blue led bubbler cus I wanted her to be more comfortable before I put anymore light in. So those things are already done.
<Cool.>
The filtration is way over what is called for. I have a hob rated for a 20 and a sponge filter on it as well with a power head attached. She ( I say she because her features seem to be less elongated which is a characteristic of the females) loves to swim around in front of it when she comes out.
<All sounds good.>
As long as shyness is just in there nature I will just continue to care for her and make friends with her till she is a bit bigger and a bit less afraid maybe.
<May happen, in time. Small (but not too small!) dither fish may help. Some people keep them with Corydoras and Brochis.>
So it may sound funny but I do worry about my fish being lonely.
<According to the scientists, they do live in groups, but the problem for aquarists is that two or three specimens will bicker because we can't easily keep the dozen or more needed for them to form a stable hierarchy without bullying. So the alternative is to choose peaceful tankmates like Corydoras that won't threaten them but will enable the Knifefish to feel secure.>
And when she is moved to her permanent tank after I'm done getting her all healthy she will be the only fish in a 75g. If I wanted to get some innocuous little companions to keep her some company what would you recommend?
<See above. A lot depends on the size of your specimen. Pretty much any surface-swimming tetra, barb or Danio that won't be eaten should work.
Bleeding Heart Tetras for example, or Congo Tetras. Giant Danios might be another option, but these fish veer towards hyperactivity, and need space.
Swordtails are another option, but won't enjoy soft water. Rainbowfish could be yet another option, but again, check water chemistry before purchase because many prefer harder water.>
Thanks a ton for your help
<Welcome, Neale.> 

Brown Knife Fish Behaving Strangely... data need, rdg.    7/11/12
Hey WWM Crew,
So here's the deal: I've had a brown knife, a cichlid,
<What/which species?>
 and a plecostomus
<Ditto>
for about two weeks now in a 25 gallon tank
<Likely too small a volume>

 (before putting them in I ran the tank for about two weeks to ensure healthy bacteria). The plecostomus just died a few days ago -- sad -- and now my brown fish seems to be on that track unless we can save him.
<Is this system cycled?>

 When I first put him in the tank, he was very shy and would simply hid in his castle with his cichlid friend (who is significantly smaller than him -- a purposeful decision to ensure they behave nicely together).
<Not necessarily>
Now, he has a white, chunky, blotchy film all over him, and glazed-over eyes; he also swims in the open, often suspending himself vertically and putting his face down into the tank's bubble stream, or he'll lay on the bottom floor, then dart up real fast to the top and either let out a huge bubble or gasp for air (i can't tell which one). His fins are also looking frayed and white-ish at the tips; I've noticed the cichlid will now go and softly nibble on the white film of the brown knife's body, which sends the brown knife scurrying away rapidly (I'm not sure if the cichlid is trying to actually eat/attack the brown knife or just nibble on the film).
My tank was a little high on nitrates
<How high? Over 20 ppm?>
 so I added two moss balls and the nitrate levels seem to be in check now. I also just did a 25% water change and added 5 tablespoons of aquarium salt
<... not advised depending on how much salts are in the resident water>
 in addition to Tetra 'AquaSafe' tapwater conditioner. Here's the tank stat's as of an hour ago: pH (8.4); Alkalinity (300); Hardness (150); Nitrite (0); Nitrate (20). The tank's temp is steadily 75 degrees, and the brown knife is still eating.
Thanks for your help,
Dustin
<Mmm, let's have you start at the beginning. Read here:
http://www.wetwebmedia.com/FWSubWebIndex/knifedisfaqs.htm
the linked files above; and here:
http://www.wetwebmedia.com/FWSubWebIndex/ChocKnivF.htm
Bob Fenner> 

African Brown Knifefish acting weird    10/18/11
Hi!
I was looking for the African's behavior, mine is <has> been shy thanks to the kids I use<d> to baby sit, but that is not the problem. Today he starts swimming like crazy and bumping with the plants and tank walls.
<Poisoned somehow... metal? Cat box? Bong n a blintz?>
When he stop he is gulping air and he is not eating nothing today. I have no clue what's wrong with him I need help. I am not an expert caring for fish tanks. Help please.
NAB
<Water change/s now... use of activated carbon; investigation as to what is in the system, water that is toxic... Shell, geode, metal? Bob Fenner>

Poor Sick Perseus BKF.    8/6/10
Okay lets start with: I have a 55 gallon tank, 4th aquarium I've set up, started with a 1 gallon and a single Glofish. I still have the Glofish in the 55 along with 3 other Glofish (about an inch long each), 1 Bircher (2 inches long),
<Not John... a Bichir>
1 Blue Snail (about 2 inches diameter of shell),
<Do see WWM re this likely Ampullariid species>
1 Albino Cory Catfish (about an inch and a half),
<Social animals... need to be in a group to do well... "be happy">
and 2 Giant Danios (about an inch and a half each)
<More here also>
and 1 Brown Knife Fish (about 5 or 6 inches long named Perseus). Sounds a bit crowded right now I know, but I'm expecting when Perseus and my Bircher are big enough they will eat the Glofish and the Danios,
<Mmm, not likely>
also I'll be getting a hundred gallon tank bottomed coffee table for Christmas so by the time they grow they will have room for expansion. When I first started this 55 up I let it set its cycle for 3 weeks, and then tested my chemicals and on my home test everything seemed fine and tank temperature was 79. So I took a water sample to the store and had it tested nitrates and nitrites were almost zero, ammonia levels were zero, and ph was a solid 6.9. So that day I bought the 2 Danios and took them home to be the first fish in my 55. Since at this time I had the Blue Snail, Glofish, Cory, and Loach (inch long when I got him) and Bircher (2 inches when I got him) in my 30 gallon, I used the 55 to quarantine the Danios. After a little over another 2 weeks the Danios were doing wonderful and happy, so I added a live banana plant and a small amount of moss around the dish it sits in. The bottom of my 55 is sand and I also have 2 4 inch bubble stones a "bank tube" (like you send money in up the tubes in the drive through lol) for them to hide in and a slice of a huge conk shell for them to play in also. I let these newly added amenities cycle with the Danios for a week they were fine and healthy so I changed the carbon in my filter and let it cycle another 2 weeks. Tested my water levels and everything checked out the same so I bagged and started to temp the fish from the 30 gallon, got them all added and everyone was happy and healthy. after a few more weeks I found a wonderful 5 inch long baby brown knife and I just had to have this fish! Brought him home and set him up in the 30 gallon (which I had vacuumed water changed and started recycling about 2 weeks before this purchase) I started quarantining him and he seemed to be doing well until about a week later when he started flashing on the giant open fake clam shell I gave him to hide in, and he started rubbing himself all over the fake plant.
<Natural behavior to a degree>
At first (since I've never had to deal with Ick before) I thought it had to be water related so I checked his water levels and ammonia was zero nitrates and nitrites showed very very low with my watercolor test and the Ph was still an awesome 6.9, water temperature was 80. I researched his symptoms and talked to my favorite fish store guy and showed him some pictures and he said Perseus had Ick (he got his name from surviving the awful things!) So he recommended "Ick Cure" active ingredients being formalin and malachite.
<Way too toxic for these types of Knifefishes>
I treated him with half the dose necessary since he's scaleless added about a cup of salt to the 30 gallons of water and raised the temp to 83
<Good>
over the course of a few days. So about exactly a week ago all of the cysts he had from the parasites seems to just be literally rolling or flaking off of him and with a 60 percent water change and a good vacuum and a teeny bit more salt his whole body cleared up even his eyes and gills and went back to a beautiful deep mahogany sheen! I continued to treat him for about 4 more days doing a 30 percent water change each 2 days. Today is Thursday and on Tuesday I noticed he was acting so much happier and healthier except he had this small red patch on the under fins of his tale, I immediately thought it was the water (malachite poisoning) so I vacuumed again and did about an 80 percent water changed. He seemed much more comfortable after the water change, added a wee bit of salt and he seemed even cozier. Wednesday however I got up and saw that this "bloody rawness" covered almost the whole tip of his tale I started looking up things online and I thought he might have fin rot but none of the pictures I saw really looked like him...and today when I got up my poor Perseus has this red string sticking out barely left and above his anus. Also, the whole small (maybe centimeter in diameter) area surrounding his anus seemed a bit swollen and a bit light brown or maybe translucent. I noticed this earlier today and I had my boyfriend help me hold him gently in the net to snap a few quick pics, I've attached 2 of them (sorry for poor quality) of his anal area where you can see the bulbous whiteness and partially see the red string I was referring to. Perseus has been swimming fine aside from being slightly wobbly when his tail gets near the glass (maybe pain related?) his skin is still a healthy black sheen and his eyes are clear. This hearty friend has made it through so much so far surviving Ick! I can't bare the thought of losing Perseus now! Please help me find out what I need to do to save my pet! Thank you so very much in advance! - Thompson
<I do hope your Knife recovers... the distended/prolapsed colon/anus can be retracted by these fishes... but only time, and good, steady conditions provided on your part will prove this to be the case. I would not "treat" the water, this fish with any remedy. Bob Fenner>

Brown knife fish... Sys., fdg.,    12/31/09
Hey, I recently (2 days ago) got a brown knife fish,
<Is this Apteronotus leptorhynchus or Xenomystus nigri?>
and it hides in its clear tube all day AND night.
<Both these species are nocturnal, and unless the aquarium is precisely right for the species, they *will* hide away and eventually die from starvation. To recap, Apteronotus leptorhynchus needs moderately warm (25 C) water with a very strong water current and lots of oxygen. Water chemistry should be soft to moderately hard, slightly acidic to neutral (pH 6.5-7, 5-10 degrees dH). Xenomystus nigri needs similar conditions in terms of warmth and water chemistry, but isn't so fussy about water current. Both will be quickly stressed, even killed, by exposure to copper and formalin-based medications.>
I have dropped two cubes of blood worms in the tank, but I don't think its eating them and I'm pretty sure they are making a mess!
<May well be. Do remember neither species competes with catfish, cichlids, etc at feeding time. Apteronotus leptorhynchus in particular should be quarantined first, or at least kept with fish that offer no competition at all (i.e., just small midwater swimmers). Xenomystus is a little more adaptable, but won't feed if it feels threatened or bullied. Neither species is a community fish in the general sense, though careful fishkeepers can keep them with appropriate tankmates.>
Is there a more convenient way to feed frozen blood worms without them dirtying everything because once it breaks apart I can siphon all the worms out... I am going to try buying live worms... If I drop a bunch of live worms in.. Will he hunt them or something?
<These fish are greedy for live and wet-frozen foods including bloodworms, earthworms, brine shrimp, krill, etc. But they won't eat dried or freeze-dried foods, and they won't compete for food. Most critically of all, if conditions are inappropriate, they simply won't feed. Apteronotus spp. are notoriously sensitive fish, and among the first fish to die when conditions aren't right. Cheers, Neale.>
Re: Brown knife fish
Thanks so much!!
<You're welcome. Cheers, Neale.>
Re: Brown knife fish
It is a Apteronotus leptorhynchus ..
<Apteronotus leptorhynchus is a lovely fish, a bit smaller than Apteronotus albifrons, but otherwise identical in terms of care.>
dude at pet store said it would be easy to keep..
<"Dude" was obviously making a sale. These fish are extremely difficult to keep. Wild fish live upwards of 15 years, but the vast majority of casual fishkeepers manage less than a year.>
I have a well planted tank (30gallons) with two coconut caves and a clear tube.
<He will need a much bigger tank eventually; I'd be saying a 55 gallon within a year or two. The size of the fish is rather less important here than its need for clean, oxygen rich water; these fish simply don't tolerate stagnant water conditions. They live in and around rapids and waterfalls, and expect not-too-warm, well aerated water.>
water conditions are fine...
<Define "fine".>
Should I not feed him for a couple days then try with live food?
<The problem with electric fish is they tend to need numerous small meals every day to be healthy. Presumably their energy demands are rather high.
In any case, starving these fish does little good, much harm.>
How long do you think it will take for it to accommodate?
<Kept on its own, should settle in within a week. Kept in a mixed community of poorly chosen tankmates, may never settled down at all.>
thanks again
<Cheers, Neale.>
Re: Brown knife fish
Okay well thanks for all the info.... The fish is swimming around now when the lights are off.. So I guess il feed it when its dark..
<Initially, this is probably best. Add modest amounts, and remove any nocturnal species (catfish, loaches) that would compete with your Knifefish.>
What's the easiest thing to feed them? worms? or crickets?
<Earthworms of appropriate size are very popular, as are live or wet-frozen insect larvae (bloodworms, mosquito larvae, glassworms, etc.). Cheers, Neale.>
Re: Brown knife fish... Fdg., using WWM   12/31/09

are earth worms from my yard okay? or do I have to buy them?
<... Read here: http://wetwebmedia.com/FWSubWebIndex/wormsfood.htm
Please learn to/use the search tool and indices on WWM. Bob Fenner>
Re: Brown knife fish  1/5/10

I got it to eat from my hands now!
<Neat! These animals do have very large (percentage wise) brains... exhibit quite a bit of intelligence, play behavior. BobF>

Brown knife and ich, reading   4/17/08
A few fish in my tank have ich I added a medication called quick cure wondering if it will affect my brown knife fish? <Mmm, yes. The active ingredients (copper sulfate and formalin if memory serves) will likely kill any Apteronotid> I would like to cure the ich without harming the Knife so what do you suggest? <That you read: http://wetwebmedia.com/ see the Freshwater Subweb... re FW Knives, their Health/Diseases, the articles on Ich, and the active ingredients in Quick Cure. Likely simply elevating temp. will "do it" here... as you will find by reading. Bob Fenner>

Brown Knifefish, wrong env., tankmates  - 02/27/06
Hello!  I have a quick question regarding my brown ghost Knifefish.  Some background, I have a 29gal tank with a Eclipse 3 hood/filter;  20-25% water changes weekly, with tank salt added each time as well as conditioners. <Don't like salt> (The filter is changed every 3-4weeks);  Livestock:  Bala shark (approx 3yr old, 7in), <Too small a tank for> albino cat (about 4-5in); a blue white striped cat (about 3in); 4 ghost catfish (about 3in each); 1 Pleco (unsure the type-about 2 in); 1 pearl Gourami (3-4in); and the newest arrival (2mo.) a 4 in brown ghost knife- Charlie Brown; Ok, here's the problem.  I have provided plenty of cover for the BGK with (silk) plants and a 6in clear glass hurricane piece for cover/protection (which is completely ignored by him!) as well as a castle figure.  My question is regarding his health and behavior.  Charlie Brown (and the crew) is fed a mix of frz. blood worms or community mix (of krill, shrimp, etc) 1x/day, although I do not actually witness him eating very much at all. He spends most of the day (vertical) in the light  b/w the bubble wall and driftwood that is situated along the back. He has recently developed red spots in the gill area, and has lost some coloration. Can you please tell me if he is ill and is his behavior normal? <Is ill... poor tankmate choices (can't compete), likes different water than much of what you list... and the salt...>   And what, if anything, would need to be done?  Thanks! Rachel S. <Place this animal in an appropriate environment. Read re this per species on WWM, fishbase.org. Bob Fenner>

Brown Knifefish/African Knifefish ... comp., systems   2/3/06 We just recently purchased a brown Knifefish from the local PetSmart.  It is about 5 inches long and seemed to be doing fine.. at first.  After 2 weeks he has developed a coating in his skin, looks like dead skin or dust. <Bad...> We are very concerned and I read on your website about the parasitic disease that can be caused by ammonia and nitrate levels. <Yes... or just "unsuitable water quality" in general. Touchy fishes (S. American) knives... that like very stable, "clean", soft, acidic water of high temperature... and live foods, no rambunctious tankmates, subdued lighting... Wish the mass-merchandisers like PetSmart would leave off with such touchy animals> That sounded like what he has.  So, my question is- will fixing the ammonia levels and nitrate levels, doing a 30% water change with conditioner and vacuuming the gravel, fix the problem? <Possibly... hard to be very confident here... as if these fishes "go too far" they are very quickly lost... if assured as to real/root problems... or not, I might go with the addition of a Furan compound (Nitrofuranace) as well>   The fish is in a 55 gallon tank with lots of hiding places and the other fish leave it alone.   Thanks for your help!   Casey <Mmm, not really a "community fish" per se... I do hope yours recovers. Bob Fenner>

Just general random questions about Knifefish...
Heh Hey there! First off, I'd like to say that I'm completely Wowed by your extensive and totally awesome information and help on all sorts of fish and such. It's been a great help to me, and quite interesting to read (Heh, I'm a bit dorky =P) <You're in good company here> I've had fish for all my life really, and I'm always trying new stuff, so naturally, when I spotted an odd looking fish, I snatched him up right away. Probably not the most brilliant of moves, but the shopkeeper assured me that he was what I could handle properly. (we've known each other for some time...) He sold him as a "Chocolate Ghost Knifefish". Upon proper research.... I couldn't find a single thing on them, really. ^^" I can't quite determine the species of fish he is (or she really, I haven't found many websites that are too helpful with sexing Knifefish.), but he LOOKS like a Black ghost knife... but with a longer face, brown-ish, and a yellow stripe and a white dot for a tail. He doesn't match up with Brown Knifefish either, he just...isn't. Are there such things as Chocolate Ghost Knives, or is he just a special brown? <Mmm, there are a few species of Apteronotids this could be. Most often sold is Sternarchella schotti: http://www.fishbase.org/Summary/SpeciesSummary.cfm?ID=48027&genusname=Sternarchella&speciesname=schotti> It's been a good couple months since we got him, and he seems very healthy and quite lively and happy. We've been feeding him frozen blood worms, but I've recently wanted to change it up a bit, too. I heard full grown brine shrimp aren't particularly nutritious though...can we feed just hatched, or is that too small/meager to last them? <The latter> I heard frozen krill was a good choice; compared to blood worms, where does that stand? <A mix of worms, insect larvae, crustaceans... live, or frozen/defrosted will do> When there's a downpour around our area, we often can find earthworms and such wriggling about, and our old fish gobble those up. However, we've been concerned that they may either lack nutrition, or possibly still have chemicals from landscaping/lawn work, is that a concern? <Yes> We often eat shrimp and seafood at my house, and though I know fresh shrimp are quite delicious and probably great for them, are the ones at supermarkets and such fresh enough? <Yes> You know, the ones laid out on ice, that are already dead? <These are fine> Or will only the live ones, until the hour before you eat, okay? <Will learn to take bits of these> Can they OVEReat? <Can, but not common> He seems to bloat really easily while he's eating, and because I'm concerned with him overeating, I normally give the rest to our other fish. However, the few times he does get to try and eat a lot, he seems to stop himself. Do they always stop themselves before they explode =P, or should I be careful with feedings? <One should always be careful here> Since he's been with the same tank for a while now, but I suppose I should check in while I have the chance, right? He's about 7+ inches, in a 46gallon tank. A blue Gourami, a gold Gourami, a red-tailed shark, a Pleco, and 2 angelfish. The fish are all about 4-5 inches in length. He's not terrorized by any of them, never seen a mark on any of them, asides from the gouramis always having spats between themselves. Any problems with these? <Should be fine> The tank is well planted, with aged driftwood, a ton of leafy plants, an excellent powerful filter, more plants, and err...more plants. =) No little tunnels for the Knifefish like I've read about having, but he seems to like the plants enough anyways. Should we find a suitable tunnel, anyways? <Mmm, not necessarily... I like transparent... glass "chimneys" or plastic... for viewing... but the plants are fine> Wow. Typing wayyyy too much now, sorry! ^^" For now, my mind has run out of pathetically inane questions to pester you with, so until later.... Thank you for all your help! <Thank you for writing, sharing. Bob Fenner>

In Love with a Chocolate Ghost Knife
Hi Bob, <Hello Susie> I have recently (three weeks ago to be exact) set up a freshwater (20 gallon) tank. My daughter has four aquariums, and has been quite successful with her fish. I went to her "fish place" to purchase a few new fish and fell in love with a chocolate ghost knife. <A beautiful and intelligent species> The owner of the shop assured me he would be fine with my mollies (5), guppies(6), Platies(2), Cory cats(2), red tail shark(1), silver stripe shark(1), leopard algae eater(1),and Neons(4). He is about five inches long and he is beautiful! I would really like to keep him, but now I have read on some internet sites that this may be bad. He seems to be fine, and prefers a rock cave to his clear tube. My questions are : <Well... it will likely eat all baby livebearers... and your Neons in time... And the "sharks" prefer different water quality... hard/alkaline versus softer/acidic... and the worst fact to relate... your tank is way too small for all these fishes.> 1.Did I make an incorrect purchase? 2.Will he kill my other fish? 3.How does he find his food (bloodworms are what the guy suggested). 4.Does he absolutely have to have live food, and if so, what should I give him. <Not live food, frozen defrosted meaty foods will likely do... offered right after "lights out" for the Ghost...> I would really like to keep him, but I do not want to do the wrong thing. <There are many other things to know about this fish and its relatives... they don't tolerate much in the way of standard fish medications... are electrogenic... Bob Fenner> Thanks, Susie

Just general random questions about Knifefish...
Heh Hey there! First off, I'd like to say that I'm completely Wowed by your extensive and totally awesome information and help on all sorts of fish and such. It's been a great help to me, and quite interesting to read (Heh, I'm a bit dorky =P) <You're in good company here> I've had fish for all my life really, and I'm always trying new stuff, so naturally, when I spotted an odd looking fish, I snatched him up right away. Probably not the most brilliant of moves, but the shopkeeper assured me that he was what I could handle properly. (we've known each other for some time...) He sold him as a "Chocolate Ghost Knifefish". Upon proper research.... I couldn't find a single thing on them, really. ^^" I can't quite determine the species of fish he is (or she really, I haven't found many websites that are too helpful with sexing Knifefish.), but he LOOKS like a Black ghost knife... but with a longer face, brown-ish, and a yellow stripe and a white dot for a tail. He doesn't match up with Brown Knifefish either, he just...isn't. Are there such things as Chocolate Ghost Knives, or is he just a special brown? <Mmm, there are a few species of Apteronotids this could be. Most often sold is Sternarchella schotti: http://www.fishbase.org/Summary/SpeciesSummary.cfm?ID=48027&genusname=Sternarchella&speciesname=schotti> It's been a good couple months since we got him, and he seems very healthy and quite lively and happy. We've been feeding him frozen blood worms, but I've recently wanted to change it up a bit, too. I heard full grown brine shrimp aren't particularly nutritious though...can we feed just hatched, or is that too small/meager to last them? <The latter> I heard frozen krill was a good choice; compared to blood worms, where does that stand? <A mix of worms, insect larvae, crustaceans... live, or frozen/defrosted will do> When there's a downpour around our area, we often can find earthworms and such wriggling about, and our old fish gobble those up. However, we've been concerned that they may either lack nutrition, or possibly still have chemicals from landscaping/lawn work, is that a concern? <Yes> We often eat shrimp and seafood at my house, and though I know fresh shrimp are quite delicious and probably great for them, are the ones at supermarkets and such fresh enough? <Yes> You know, the ones laid out on ice, that are already dead? <These are fine> Or will only the live ones, until the hour before you eat, okay? <Will learn to take bits of these> Can they OVEReat? <Can, but not common> He seems to bloat really easily while he's eating, and because I'm concerned with him overeating, I normally give the rest to our other fish. However, the few times he does get to try and eat a lot, he seems to stop himself. Do they always stop themselves before they explode =P, or should I be careful with feedings? <One should always be careful here> Since he's been with the same tank for a while now, but I suppose I should check in while I have the chance, right? He's about 7+ inches, in a 46gallon tank. A blue Gourami, a gold Gourami, a red-tailed shark, a Pleco, and 2 angelfish. The fish are all about 4-5 inches in length. He's not terrorized by any of them, never seen a mark on any of them, asides from the Gouramis always having spats between themselves. Any problems with these? <Should be fine> The tank is well planted, with aged driftwood, a ton of leafy plants, an excellent powerful filter, more plants, and err...more plants. =) No little tunnels for the Knifefish like I've read about having, but he seems to like the plants enough anyways. Should we find a suitable tunnel, anyways? <Mmm, not necessarily... I like transparent... glass "chimneys" or plastic... for viewing... but the plants are fine> Wow. Typing wayyyy too much now, sorry! ^^" For now, my mind has run out of pathetically inane questions to pester you with, so until later.... Thank you for all your help! <Thank you for writing, sharing. Bob Fenner>

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