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.>