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FAQs on Black Ghost Knifefish, Apteronotus (Sternarchus) albifrons, Foods/Feeding/Nutrition

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

Related FAQs:  Knifefish Feeding, BGK FAQs 1, BGK FAQs 2, & FAQs on: BGK ID, BGK Behavior, BGK Compatibility, BGK Selection, BGK Systems, BGK Disease, BGK Reproduction, & Knifefishes 1, Knifefishes 2, Knifefish Identification, Knifefish Behavior, Knifefish Compatibility, Knifefish Selection, Knifefish Systems, Knifefish Disease, Knifefish Reproduction, Electrogenic Fishes, Notopterid Knifefishes (Clowns...),

 

Re: Tough Decision to Make... now fdg. BGKs      6/17/17
Ok, will keep going with the daphnia, Cyclops, baby brine shrimp, and I'll chop up blood worms for him (those are the only foods besides the processed flake or pellet type foods available in this area). I'll also try some
boiled egg yolk (problematic and messy, I know) but it did seem to give the BGK a boost.
<Indeed; an old-timey source of nutrition for baby fish, picky fish of all types. Best used a few hours before a water change though, unless used very sparingly.>
Thank you!
<Welcome. Neale.>
Re: Tough Decision to Make

Do you think it would be prudent to treat him with Prazi Pro? I thought that if its going to be tough getting food into him that I want to be sure he's getting everything from what he does eat.
<If he's really hollow-bellied (concave around the abdomen) then sure, pre-emptive anti-worming is unlikely to do any harm. Otherwise, if he's basically normal-looking and actively feeding, I'd feed him generously over the next week and see how he looks before doing anything else. Cheers, Neale.>

Re: Black ghost knife - quarantine and tank mates. Water quality/sys.   11/18/16
Hello again,
I finally got the GH and kH test kit, my readings are:
tap water GH - 11 drops, hence 11 degree about 200 ppm
tap water kH - 6 drops, hence 6 degrees about 100 ppm
the drinking water dGH is about 3 degrees 50 ppm
The tank dGH is about 8 degrees, so I'm guessing it should be fine and I don't have to mess with water chemistry. Now ill just have to wait and get the fish :) I cannot thank you enough for responding to all the e-mails even if they're silly. Thank you ! You've been a life saver.
<Thanks for the kind words, and I agree, your water chemistry sounds fine for Black Ghost Knifefish. As we've discussed before, water quality and oxygenation are more important. Good luck, Neale.>
Re: Black ghost knife - quarantine and tank mates. Now feeding, avoiding B vitamin deficiency   11/18/16

hello,
I was just going through your article on Thiaminase and vitamin B1 deficiency in fish. As this is important, I was looking into foods that are rich in this to form a varied diet for the BGK. and I wasn't sure if some of these foods can be fed to these fish Hikari pellets, earthworms, cucumber, beef heart, shrimp, green peas and tilapia fish fillet in general
<These are all good. Beef heart should be used sparingly, as it is quite rich, but is a classic "safe" food for aquarium fish because it isn't fatty.>
foods that I came across is rich in Thiamine are - mackerel,
<Sparingly. Good in terms of health. But oily, so makes a BIG mess. I've used mackerel on the day I do a water change, so I can change the water after the fish have eaten it up. Make sense?>
lean pork (can pork be fed for fish? I'm a vegetarian so I'm not sure about how meat works except that I need to take off all the fat from it first) ,
<No, don't feed pork to fish.>
squash,
<Yes.>
liver (chicken or pork),
<No.>
pistachio,
<Unlikely to be eaten, but tiny bits might be eaten by some herbivorous fish. I doubt Black Ghosts will eat it though.>
wheat bread
<Very occasionally to herbivorous fish does no harm. But nutritionally not particularly useful because most fish don't naturally consume starch.>
and yeast.
<No.>
If this doesn't work out, can I use vitamin b1 supplements meant for humans?
<Theoretically, but getting the dose right will be difficult. Normally freshwater fish don't need vitamin supplements. Just offer a nice varied diet.>
same for erythromycin cause its difficult to get hands on API here in India.
<Understood. But again, dosing is difficult, so unless a vet can help you, best avoided.>
Also, will fluctuations in dGH have the same affect as ph ? cause' my tank dGH had lowered to 8 from 11 in 3-4 days.
<General hardness shouldn't normally vary much, if at all. If it does, then the best approach is to do small, frequent water changes to "reset" it. Say, 10-15% every couple of days.>
Thank you in advance. Sorry about asking too many questions !
<Most welcome. Neale.>

Community tank, fish are greed u. Mis-mix of FW trop.s, feeding        3/31/16
Hi there, have read over a lot of your Q&A but none of the questions really answer what I am experiencing. I have a cobalt Gourami, blue ram, gold ram, Cardinal tetras (12), two Kuhli loaches and a BGK.
<Yikes; the Apteronotid needs a large volume as it grows... and will eat your Cardinals in time>
My question is, my Gourami, blue ram and tetras are quite greedy at feeding time and I've noticed my loaches and ghost knife (and also my gold ram who is new to the tank) don't really get any food. I've switched the food up
using flakes to distract the greedy fish the dropping in blood worms that sink to the bottom for the BGK and loaches but the greedy fish just manage to eat it all before the others get a chance. How can I make sure all my fish are getting fed properly?
<Ahh; as you've noted and are doing... feeding in two places at once... with nutritious foods... that sink... And offering at least one of the daily feedings towards "lights out" time; as the Knife and Loaches are more nighttime foragers. Do see/read on WWM re the foods/feeding/nutrition FAQs for each species here>
Any help would be good help. Thanks for taking the time. Jack.
<Thank you for sharing. Bob Fenner>
Community tank, fish are greed u.... Neale's go.     4/1/16

Hi there, have read over a lot of your Q&A but none of the questions really answer what I am experiencing. I have a cobalt Gourami, blue ram, gold ram, Cardinal tetras (12), two Kuhli loaches and a BGK.
<Will remind you that the Ram Cichlids have very, VERY specific needs. Very warm, very soft and very acidic water conditions. In anything else their lifespan is usually measured in months, often weeks. To sum up:
25-28C/77-82 F; 1-5 degrees dH; pH 5.5-7.0. Such conditions will suit Gouramis and Cardinals just fine. The Kuhlis should be okay too. But the Black Ghost needs strong water current (which Rams and Gouramis hate) and
lots and LOTS of oxygen. Again, their lifespan in the wrong conditions is dismal, and the vast majority, easily 90% of them, sold to casual aquarists die within a year. Shame really because they're really nice fish when fully
grown. They get enormous, by the way, so be sure to plan ahead. Some folks reckon on getting a bigger tank when the Black Ghost is bigger. These folks end up with a dead Knifefish. A "tiddler" measuring below 15 cm/6 inches is fine in, say, a very well maintained and understocked 150 litre/40 US gallon tank; but by the time if gets to 20 cm/8 inches, it'll need something closer to 200 litres/50 US gallons, and you should be planning on not less than 350 litres/100 US gallons for an adult, which should be around 30-40 cm long, occasionally a little bigger.>
My question is, my Gourami, blue ram and tetras are quite greedy at feeding time and I've noticed my loaches and ghost knife (and also my gold ram who is new to the tank) don't really get any food.
<What are you offering?>

I've switched the food up using flakes to distract the greedy fish the dropping in blood worms that sink to the bottom for the BGK and loaches but the greedy fish just manage to eat it all before the others get a chance.
How can I make sure all my fish are getting fed properly?
<Right, now, there are some different ways to tackle this. Let's start by choices of food. Your Kuhli Loaches are nocturnal, so you can add a small amount of sinking catfish pellets or the odd algae wafer each night and let
then get on with it. Cardinals and Rams are vision-oriented animals and at night can't forage for food. Problem solved. The Black Ghost is a bit more of a challenge. They come from fast-flowing parts of rivers and streams
around rocks and waterfalls. They forage primarily in deep water using the electric sense rather than eyesight to navigate. They may also use their electric sense to detect prey, but I'm not sure about that. In any case,
they're feeding on insect larvae, crustaceans, and occasionally very, very small fish. They need a suitable mix of live and/or frozen foods (not freeze dried and certainly not flake) to survive, and like a lot of these electric fish, they're actually quite heavy feeders, prone to starvation if under-fed. Frozen bloodworms make a good food for enticing them after purchase, and live Tubifex are even better for stubborn non-feeders though they're risky because of where they're collected. You can also try live brine shrimp and live daphnia, or Spirulina-enriched frozen brine shrimps.
Basically, a mix of four or five different invertebrates. Offer them when the lights are out but the room lights still on, ideally subdued so it's all nice and shady in the tank. That's when your Knifefish will be best able to feed. Once settled and feeding these fish have proven to be intelligent and quick to learn how to compete with other fishes at feeding time. But initially your Knifefish is probably going to be half-starved (they don't often feed in aquarium shops) and needs you to appreciate its specific requirements and act accordingly.>
Any help would be good help. Thanks for taking the time. Jack.
<Most welcome. Neale.>

Vegetarian BGK?     1/3/15
Hi,
<5.5 Megs.... grrrrr>
Thank you so much for all the great advice and information. A few months ago I moved, and this house has a small pond (no fish, just dirty water), and after reading your advice, I thought of the pond. I grabbed a net and began swiping the pond and I had no idea I was sitting on a huge culture of bloodworms or some other type of red aquatic worm. So, I moved her into a 10gal alone to make sure she had no competition for the food.
<Too small a world...>

She was very lethargic for the first day and didn't eat nor move from her hiding spot, but the next day I did see her eat a worm. Well, she recovered and I got her eating frozen and pellets inside the 10gal before moving her. Now, she is a completely different fish. As soon as food hits the water, she is out looking for it, whether the lights are on or off. She even eats the algae wafers I give the Otocinclus'
<Good>
But, I ran into another issue. In the 10gal I had 2 Platies that were in quarantine for 2 weeks before I had to move them out to make room for the BGK. Well, one of the Platies had Ich and the BGK got it. So, I just moved the BGK into the main tank to treat one tank and just take apart the other.
I followed the advice given to another about Ich and raised the temperature to 86F/30C for 2 weeks.
<Very good>
The BGK had it really bad, she would constantly be scratching herself and had many spots on both sides. The heat method works perfectly, she lost all spots within a week, and seemed normal.
<Tres bien>
Well, a few days ago I had to euthanize a Platy because it had developed dropsy (Did not catch it in time).Then, the next day, I found what looks like an Ich spot on another Platy. It seems that the BGK is stressing them out at night, which is a huge change, I guess they love to bug their smaller tank mates when healthy. So, I moved all Platies to the  quarantine tank. From what I have read, if one fish has Ich, the tank has it too. The BGk shows no signs of white spots nor do the Danios and Otos I have. I just finished the high temperature treatment a week ago, would it be safe to slowly raise it again to 86F?
<Yes; can be raised quickly; lowered slowly... about a degree F. per day>
I have slowly raised from 79F to 82F in 2 days, but am unsure if it's dangerous or necessary to subject the tank to
high temperatures again.
Sorry for the bad pictures, but there she is eating a pellet, and thank you so much for the great advice and help in saving this fish!
<Will share w/ Neale. Bob Fenner>
re: Vegetarian BGK? /Neale     1/3/15

Hi,
<Orlando,>
Thank you so much for all the great advice and information. A few months  ago I moved, and this house has a small pond (no fish, just dirty water), and after reading your advice, I thought of the pond. I grabbed a net and began swiping the pond and I had no idea I was sitting on a huge culture of bloodworms or some other type of red aquatic worm. So, I moved her into a 10gal alone to make sure she had no competition for the food. She was very lethargic for the first day and didn't eat nor move from her hiding spot, but the next day I did see her eat a worm. Well, she recovered and I got her eating frozen and pellets inside the 10gal before moving her. Now, she is a completely different fish. As soon as food hits the water, she is out looking for it, whether the lights are on or off. She even eats the algae wafers I give the Otocinclus'
<Useful info, and good to hear this fish has settled in nicely. Obviously, 10 gallons isn't viable for a Black Ghost Knifefish in the long or even medium term, but for a few weeks while you fatten up a juvenile specimen, no harm will be done. Just keep oxygen level high through robust circulation of the water and perform regular water changes to keep nitrate down.>
But, I ran into another issue. In the 10gal I had 2 Platies that were in quarantine for 2 weeks before I had to move them out to make room for the BGK. Well, one of the Platies had Ich and the BGK got it. So, I just moved the BGK into the main tank to treat one tank and just take apart the other.
I followed the advice given to another about Ich and raised the temperature to 86F/30C for 2 weeks. The BGK had it really bad, she would constantly be scratching herself and had many spots on both sides. The heat method works
perfectly, she lost all spots within a week, and seemed normal.
<Good.>
Well, a few days ago I had to euthanize a Platy because it had developed dropsy (Did not catch it in time).Then, the next day, I found what looks like an Ich spot on another Platy. It seems that the BGK is stressing them out at night, which is a huge change, I guess they love to bug their smaller tank mates when healthy. So, I moved all Platies to the quarantine tank. From what I have read, if one fish has Ich, the tank has it too.
<Almost always the case, yes. Though fish to have an immune response, and in strong, healthy fish this can often resist Whitespot/Ick sufficiently that you don't see any symptoms.>
The BGK shows no signs of white spots nor do the Danios and Otos I have.
<Would still treat the tank and everyone in it.>
I just finished the high temperature treatment a week ago, would it be safe to slowly raise it again to 86F? I have slowly raised from 79F to 82F in 2 days, but am unsure if it's dangerous or necessary to subject the tank to high temperatures again.
<The high temperature isn't ideal for Platies or Black Ghosts as a permanent situation, but short term, shouldn't be a problem. Just double check there's plenty of oxygen. Supplemental aeration may be necessary.
Certainly, ensure the filter agitates the water's surface AND keeps the bottom layer of water moving. Lack of oxygen, not heat, is what stresses fish at high temperatures.>
Sorry for the bad pictures, but there she is eating a pellet, and thank you so much for the great advice and help in saving this fish!
<Cheers, Neale.>

Black Knife Ghost fish - Feeding Habits      12/27/15
I've got a South American tank and, being a fanatic, I don't want to introduce anything outside of a S.American habitant.
<Not a bad approach at all. But alternatively, think about stocking as per its environment. In other words: this is a fish that lives in river rapids where there's lots of oxygen but not much light. Numerous African and Asian species would fit such a tank better than, say, a random selection of South American characins that wouldn't actually enjoy strong water currents. Make sense?>
I've also got a snail problem. Will a BKG forage and eat the small live snails?
<Nope. Certainly not the Melanoides type snails that can become a pest.
Loaches and some Synodontis would work slightly better, but my suggestion would be Clea helena. You'd hardly see them, so he fact they're Asian isn't a big deal. The pest snails you've got probably aren't South American!>
Everything I've researched seems to hint at this, but I haven't found a definitive reference.
<Apteronotus are specialist micropredators. They consume insect larvae more than anything else, though probably take other small animals occasionally.
What they don't have are the jaws needed to process snail shells.>
Thank you, in advance!
Glenn
<Cheers, Neale.>

Vegetarian BGK?     11/8/15
Hi,
First off, I love how informative your site is for someone new to the hobby, thank you so much!
<Thanks for the kind words.>
Now, I have a 3-4inch BGK that I have had for almost a month in a 20gal long with five zebra danios and one Nerite snail.
<A short term combination, I hope!>
For filtration, I have two HOB's rated for 20 gals (read that filtration and water movement is very important for BGK's)
<Extremely. They inhabit the areas around riffles and waterfalls. They need middling water temperature (24-26 C) and lots and lots of oxygen.>
I am slowly preparing a 125gal tank that should be up and running mid February, which will have the BGK, a Senegal bichir and blood red parrot.
<The Blood Parrot has been bred to have an odd shape some find pleasing.
Unfortunately, this means it has a deformed spine and poor swimming ability. Not really viable for life in a riverine set-up like the one your Black Ghost wants.>
I discovered that my BGK did not eat in the mornings, so I started feeding her more at night.
<Correct.>
My concern is that I am not sure that she is eating much. I have seen her eat frozen bloodworms a couple of times, but she seems to ignore the meaty foods and will just make holes in my plants and chew on the stems.
<Desperation. These fish are micro-predators. Zooplankton and worms are what they feed on in the wild.>
Every other fish dashes straight to the food, but my BGK seems to not care at all.
<Yes.>
I do see her poop, so I know she is eating something. Also, since BGK's are nocturnal, how would one go about checking on fish' well being without having the same amount of visual light and time?
<You can't be sure. Which is why you make sure Black Ghost Knifefish aren't kept alongside any other nocturnal fish (catfish, loaches, spiny eels, bichirs, etc.). That way, only they will get the food you put out at night, such as bloodworms, krill, bloodworms and tiny pieces of seafood such as cockles, mussels and shrimps (shrimps and mussels used sparingly because they contain thiaminase). Feed moderately so you don't end up with piles of uneaten food left behind for the filter to deal with. Do read:
http://www.wetwebmedia.com/fwsubwebindex/bgkfdg.htm
Bear in mind that these fish have big appetites. They eat well when they're happy and offered the right live and frozen foods. Lack of appetite almost always means they're stressed.>
Thanks again!
<Most welcome. Neale.>

re: Vegetarian BGK?
Thank you so much for the reply.
<Welcome.>
I started feeding the BGK at night, when I would see her out, and it seemed like she ate and was growing. Now, for the past 3 days, she wasn't coming out when the lights were turned off, which was something she did before.
Today, I turned the lights on and the BGK was laying on its side on the gravel and did not swim to her regular hiding spot under a piece of driftwood.
The BGK looked much smaller or thinner than before, it seems.
<Does sound like its starving.>
Her color, fins etc look perfectly healthy, she has no spots, no visible injuries.
She did not move when the light came on nor did she move when other fish would bump her. She finally moved when I gently touched her with my net. I have tried live mealworms, frozen bloodworms/brine shrimp, live earthworms, pellets and flakes.
<Review temperature (low to middling, 25 C/77 F ideal). Check aeration (plenty). Check water chemistry (soft to medium hard). Do offer small live foods: daphnia and brine shrimps. These are very tempting. Turn off the filter for 5-10 minutes if needed while the Ghost Knifefish feeds. But the point it, the foods must be small and live. Mealworms much too big. Do
think of BGKs as consumers of tiny prey animals, zooplankton and small worms.>
I do water changes every Wednesday (20% change) and Saturday (40-50% change) and all other fish seem very happy. I test my water with API freshwater liquid test kit twice a day(morning and night), and do two water changes a week to keep nitrates under 10ppm at all times. The only change I have noticed in my tank are the danios becoming more aggressive towards each other, one of them even had a chunk taken out of his belly.
<How many Danios do you have? In small groups they can be aggressive. The males, at least.>
Thank you!
<Cheers, Neale.>
re: Vegetarian BGK?

Thanks for the quick response, Neale!
I had 6 danios, but the one that was being picked on by the all the other danios passed away. They do not harass the other fish, but they do chase each other around.
<Correct; this is what they do. Not the most "peaceful" community fish, and apt to be bullies.>
Would chopping the meal worms count as live food or does it need to be alive while the BGK eats it?
<Worth a shot. But honestly, Mealworms have a very tough exoskeleton that most fish can't deal with. Apteronotus are true micro-predators. Understand that, and feeding is a lot simpler.>
I have been observing the BGK all morning since she is sleeping out in the open, I tried moving her driftwood to cover her from the light, but a few minutes later she moved right back in full view and light.
<Yes.>
So, I moved my strip of light to one side, keeping her side much darker to help her feel comfortable. I think I will try my baby monitor that has night vision in order to see if the BGK is actually eating and coming out at night. From the picture I sent, does she look thin?
<Hard to say. But unless you're providing ample small live foods, and once settled, frozen alternatives, your specimen will be unlikely to thrive.
What to say? Merely that the vast majority of BGKs don't live more than a few months to a year in captivity. Hardly any (one in a hundred, maybe) reach proper adult size of a couple feet or so in length. They are difficult to feed, maintain. Cheers, Neale.>

BGK killing spree! Hahaha! Feeding, reading      6/9/14
Hi there,
<Amanda>
I have a black ghost knife in my tank, he's beautiful and shamelessly my favourite child! He goes by the name of Joshua. :D
I used to buy neons but he ate them all the time so I now buy him gudgeons around every fortnight. He usually eats the lot (10-15) in a few days but the batch I got a couple of days ago are larger than what I normally buy. They gave me 15 of them and though many are gone, I had to pull out two dead ones last night as I didn't want their carcasses messing with the tank water. Now tonight I have gotten home and there are three more dead ones and only three live ones left. So he must have eaten some today (in broad
daylight!) but I don't know if he is going to eat the last dead ones or if I should be pulling them out immediately...
<Yes I would>
Are they too big for him to eat?!
<Perhaps; though I've known of fishes, including this species, to develop a "killing spree" as you state above>
He's only small still, around 10cm long and I've had him for around 18 months. I'm not sure if this is just natural behaviour and he will eat them later so I should leave them be? Or if I should remove them as he probably won't eat them?
<I would change this fish's feeding entirely... Read here:
http://wetwebmedia.com/FWSubWebIndex/bgkfdg.htm
and the linked files above. The live fish as food... too expensive, inconvenient; introducer of disease... and promoter of this poor behavior.
Bob Fenner>
This may be a silly question, sorry if it is... Just not 100% sure on this one, this is certainly odd behaviour for him. Any help would be hugely appreciated.
Oh also, he's the only predatorial fish in the tank now as I re-homed my veil angel as there just wasn't the space for him. None of Joshua's tank mates would be killing them. (4 guppies/1 glass cat fish/2 cleaning fish)
Sincerely,
Amanda Robertson

Emaciated BGK... in w/ breeding Ancistrus in a too small world     7/2/12
Hi there,
I'm concerned about my BGK who I've had for about a year in a 90 litre
<Needs much more room than this. Read here: http://www.wetwebmedia.com/FWSubWebIndex/bgksys.htm
community tank (2 gouramis, 6 neon tetras,
<Not compatible...>

 1 peppermint Bristlenose, 2 Bristlenose plus their fry (last count about a dozen
<Neat!>
) - still babies but will be rehomed before they get too big. My BGK has always thrived but the last few days he has suddenly lost a lot of weight and become emaciated (top of his head sunken in, really anorexic looking). He was lethargic and seemed to be breathing heavily (not gasping but gills working harder than they should?) - so I reduced the water temp from 26-27 C to 24-25 C to make more oxygen available.
<Good>
Also he was still eating but not as much, and not as eager as he usually is, with his main diet of frozen bloodworm
<See WWM re these sewer fly larvae... I'd diminish or eliminate their use... implicated in disease issues>

 (he also gets a mixture of beef heart, shrimp, fish, as well as picking on flakes, algae discs, that are for the other fish).
<Try some (live if available, frozen/defrosted if not) Tubificid worms>
I have started feeding him diced cooked prawns (human grade) and he is eating a lot more and seems to be more himself. But I'm really worried about his weight loss. He also has 2 white spots on his body that look a bit 'fluffy', could this be a mild case of Ich?
<Mmm, not likely, no>
One of my neon tetras had a little case of cotton mouth(?) which has healed, only other issue is one of the other tetras which lost an eye (probably from BGK) -
<Telling>
 he now swims on a slight tilt and has slightly shredded fins, assume because he gets picked on a bit - but are otherwise fine. (Neon tetras are tough as nails!) I have been too afraid to add any meds or salt since GKF is so sensitive to these things. The only changes to my tank lately have been the addition of some new plants, and the addition of the Bristlenose fry since my adult pair have decided to mate like crazy! The male has taken over the submarine to care for the eggs,
<This aggression is likely the root cause or at least a large contributor to the loss of health of the Knife... one of them needs to be moved, now>
 one of the places my BGK liked to hang out until the BN banished him (he still has a nice hollow driftwood log however - his most favourite place). Water parameters are pH 7.4, ammonia 0, nitrate 0, nitrite 20. Don't have a hardness test but the tap water where I live isn't hard. I admit that I'm not an expert but I love my fish and want to do the best for them!
Adele
<Read and heed. Bob Fenner> 

Black Ghost Knife, fdg.      4/19/12
Hello Wet Web Crew,
I have a black ghost knife fish that is eating my live plants!  He really likes my ruffle lace plant, and I'm concerned as I though they were just carnivorous fish. Is it safe for them to eat plants?
<Yes>
 Normal behavior? 
<Yes>
Or am I not feeding him enough?
<Does the "stomach area" of the fish appear thin, pinched in?>
 Currently he gets fed half a frozen blood worm or brine shrimp cube every day or a Tubifex worm cube. I also see him steal some flake food when I feed the other fish in the tank.  He's small only about 2-3" long and I've had him about 1.5 months. He seems fine I'm just concerned as this is my second attempt at keeping this species and I want to be sure he's happy and healthy.
Thanks so much!!! 
<Welcome. Bob Fenner>

Black ghost knife fish hurt bottom fin and won't eat... Nutr. and in w/ incomp. tankmates    2/29/12
Hi, I have had my black ghost knife fish for over a year and a half now in a 60gallon tank with 2 Severums, a jewel,
<Mmm, not really compatible w/ these cichlids... and the Severums will need this volume plus for themselves>

 a Bala shark, a cribnasis, a Pleco, and 3 rainbow fish. My knife is about 7.5 inches long and eats a variety of frozen and freeze dried bloodworms.
<See WWM re these sewer fly larvae. Implicated in disease>

She has had a few issues in the past with cuts in her pectoral fins,
<? From what?>

but she has been fine for a while. Recently however she has stopped eating for over week now, and she isn't hiding in her cave anymore, instead she's just laying along the side of the tank. her entire bottom fin is all severed like a feather.
<... see above. Needs to be moved elsewhere, and fed better foods. See WWM re: http://www.wetwebmedia.com/FWSubWebIndex/bgkfdg.htm
and the linked files above>
 The end of her tail is also red and bloody, and she has a Slit on the top of her. Right before the white in her tail. It seems like this happened over night.. What do I do?
Thanks, Aubrey Theisen
<... read, act. Bob Fenner>

Why my Black Ghost Knife Fish don't eat dried bloodworms?   12/27/11
Hello Sir,
<Unnati>
Thanks for excellent site.
<Welcome>
I read all your FAQs, but still I have one unanswered question, Why my Black Ghost Knife Fish don't eat dried bloodworms?
<Mmm, perhaps the water quality... other tankmates... Oh! I see below... likely the Ich, and/or treatment for the same has made this fish go off-feeding>

I am a newbie when it comes to aquarium. had a bad Ich patch with my fish tank and lost fishes, could not identify it as they were all white in color, my BGK got it very late hence I would identify that this is Ich, this is the only fish I have now n don't wanna loose him.
<Mmm>
*Ich cure I took*: when the tank had Ich, I removed fish in separate water (again was kept aside 24 hrs earlier), cleaned the whole tank. Kept the fish aside for 24 hrs. Then shifted it to fish tank by using 50% water (which I had kept it aside 24hrs earlier) and the 50% of water where fish was kept. Used blue color liquid in water which my local shopkeeper gave (I guess its Methylene blue) along with water conditioner. Used heater to raise the temp to 86F and added salt.
<Good>
 The Ich is not that visible in fishs body but it tried to rub the body against the transparent tubes and PVC pipe I have kept in the tank hence I assume that Ich is still there. Its been 3 days now I have raised a temp hence would continue for few more days. (As I read that we should treat Ich at least a week).
<Yes>
*Water change:* I change 1/4th water every day by turning off the heater with new water which I have kept it aside for 3-4 days before using it. I use small pipe to remove the water and dirt if any and pour the new water gently so as my fish will not be disturbed.
*Today water condition:*  The water looks clear but if I see it across carefully, I see some thread like stuff flying all over when I start my filter. Donno what it is hence I use the Aquarium Fish Catcher Net to remove it to my best.
*Smell of Water:* Water does not smell bad.
*Aquarium size :* 2ft length X 1ft height.
*Filtration:* I have bio sponge filter which is always on except in night time. Have one Hydro-Sponge ProFilter, one internal filter which I keep on for 15 min.s a day.
<I'd leave all filters on continuously>
*Decor:* No gravels, no larger stones or decor. I had one but the fish got hurt by rubbing against it so removed it. I have now two transparent tubes and one PVC Tube. And two small plants attached to small stones with plastic band.
*Lights:* I keep aquarium lights off as I read that it will less stress the fish. I often cover the fish tank with the cloth also sometime.
*Food:* earlier I tried flake food, but realize that my BGK does not eat it hence got dried bloodworms. Since they float in water, I tried to hand feed fish but no use. Then I soak them separately in aquarium water only and tried to put them near the fish in the night time hoping in morning fish will eat. But they were simply lying around the tank in morning. I cleaned them in morning. I keep food overnight to fish and clean it in morning.
<Please read here: http://www.wetwebmedia.com/FWSubWebIndex/bgkfdg.htm
re food choices>
*Behavior of Fish :* The fish almost spend the entire day sleeping in tubes without moving.
<What they do. Are nocturnal>
 When I start the internal filter, it moves but that's it.
Fishs fin is straight and not attached to the body. It does take a round around the tank once we switch off all the lights, but again the same old story.
What am I doing wrong? Why my fish don't eat?
<Wrong foods, fed at sleeping time... not where the fish lives...>

 Its been almost 2 weeks now I have had him and the Ich bad patch was there last week, the exact cure I started 3 days back.
Sorry to bother you with the same old questions may be, but I would appreciate if you can reply me as I have no clue whats wrong and how long will my BGK survive?
<Read where you've been referred>
Regards
Unnati
<And you, Bob Fenner>
Re: Why my Black Ghost Knife Fish don't eat dried bloodworms?   12/27/11

Thanks a lot  Bob for such a fast reply and all kind help.
i would now leave all filters on continuously. I will buy some live bloodworms today and would feed him just after turning off the light.
<Ah good>
you have mentioned that <Wrong foods, fed at sleeping time... not where the fish lives...>
...........will that means i have to keep the live bloodworms away from his current location?, he usually rest in PVC tube ...so may be away from it?
<The foods need to be placed near the bottom, where the Knifefish is>

just contradictory hence confirming ...as the person in article :
http://www.wetwebmedia.com/FWSubWebIndex/bgkfdg.htm , said "he usually missed everything that doesn't drift about 1/8th of an inch in front of him,"
<These fishes (Apteronotids, other "knives") vision is poor... but electromagnetic sense w/in a few inches is keen>
So please guide
Thanks once again for wonderful help.
god bless you guys.
Regards
Unnati
<And you, BobF>
Re: Why my Black Ghost Knife Fish don't eat dried bloodworms? 12/29/11
Thanks Bob and the good news is all my bloodworms (10-12) are all gone in night time and i could see my fish swimming :)
<Ah good>
i had kept them in glass bowl in fish tank, fish just got inside and was enjoying his time n eating
am so happy to see him eating .... am sure now he would be fine and will survive.
yeppeeeeeeeeeee!!!!!
thanks thanks once again .... you saved a little life
god bless you and of course i would be always thankful
Regards
Unnati
<Welcome. BobF>

Black ghost knife and Butterfly fish feeding 1/28/10
Hello Neale, I have finally been able to feed to black ghost knife on frozen bloodworms! As I was rifling though a kitchen drawer, I found a needle-less syringe, able to hold maybe half a glass of water at a time.
I've simply sucked up frozen bloodworms thawed in water, and then squirted it down to him...
<Ah yes, the old turkey baster trick. I often recommend these kinds of tools to aquarists. They are useful in all kinds of ways.>
Of course, he usually missed everything that doesn't drift about 1/8th of an inch in front of him, so propelling it *at* his face usually works... and my Ctenopoma ("Happy") is more than generous to help clean up what he doesn't eat. I'm just glad he's finally getting enough to eat... I'll be using this technique with my Tyre track eel, as well. Oh, and a
quick question: I've recently been feeding my silver dollars peas (the Ctenopoma tries them too), and was wondering how often I should give them some?
<As often as you want. 2-3 times per week should be sufficient, but you won't overdose them.>
Also, I'm purchasing a Butterfly fish soon, and bought "cichlid staple" meant for Oscars and such. They float, and I assume they are relatively nutritious... Along with frozen bloodworms, frozen brine shrimp, and the small flies you recommended, would I be able to feed these to it?
<Yes; indeed, once the Butterflyfish is settled, it is very wise to make good quality floating foods (like Hikari Cichlid Gold) the staple food.
These are very nutritious. You'll still want to use live and/or wet-frozen foods occasionally, simply to provide some fibre and so avoid bloating, but good pellet foods are a fine staple. Do review what we've said about feeding Pantodon, here:
http://www.wetwebmedia.com/FWSubWebIndex/afbflyfshfaqs.htm
>
Thanks! -Jack
<Cheers, Neale.>

BGK not eating -05/15/08 Hello, It has been three weeks since I have bought a 8cm BGK and he is my quarantine tank. It's got black sand, black cave, and no lights with good filtration so I assumed he would feel comfortable in there. He refuses to eat. He only eat around 2 bloodworms a day (from frozen) and occasionally nips at very think slices or prawn I put in there. <Apteronotus albifrons is an extremely demanding, difficult to keep fish. For very expert fishkeepers only! Live foods are (to be honest) essential immediately after import, and you should be providing live bloodworms each night.> Tank at 28 deg Celsius pH 7.8 Nitrate: 0 Nitrite: 0 Ammonia: 0 <All fine, though these fish do prefer soft, acid water.> I have no idea why he won't eat. <Wants live food.> I have also tried bits of mussel, which I see him nibble at but never manages to finish more than a quarter of and I have tried bits of oyster as well. And I have also tried to feed him jellied daphnia. <Oh.> Is there anything I can do to make him eat? He looks a bit thin, but other than that he has no infections or diseases. Thank you, Neervana. <You *must* fix this soon: when wild-caught fish lose weight, you have serious problems. Because wild fish have wild parasites, if their immune system gets stressed, you have a high likelihood of having to deal with a disease as well as starvation. So buy some bags of live bloodworms, and use a pipette or similar to drop these in front of his cave. You should perhaps be feeding about 20 bloodworms per night to a fish this size, perhaps more, but certainly not less. Very small earthworms could be tried, but these have to be small enough that the fish could eat them whole. Cheers, Neale.>

Black Ghost Knifefish Feeding 1/30/08 Hello, <Hi Karen, Jeni/Pufferpunk here.> Thank you for having such a trustworthy, informative website. <You're very welcome!> I have an 8 inch long Black Ghost Knife. I try to keep it's diet as healthy and varied as possible. It eats fresh shrimp, frozen bloodworms and earthworms. My problem is that I can't get earthworms, right now, because the ground is frozen! So I have been looking for alternatives to the earthworms. Are either butterworms, waxworms or silk worms a suitable replacement? These I can get at my local pet store. <None are suitable for most fish to eat, in my opinion. They have a hard outer skin, called "Chiton", which is difficult to digest. They are also very fatty. I get my earthworms from Kmart or other places that sell bait. Even some LFS sell them. You can also feed them live blackworms (gotten at many LFS) & frozen Mysis shrimp. Happy feeding! ~PP> Thanks in advance, Karen

Black Ghost Knife fish feeding   8/30/07Hello there, <Greetings.> First I would like to say thank you for such an informative site. I have been using it for quite a while now. <Glad you're enjoying.> I have 2 Black Ghost Knife fish (in separate tanks) they are both about 7 inches long. Right now their diet consists of raw shrimp, earthworms and frozen bloodworms. I would like to expand on that to give them the best , safest diet possible. One guy at our LFS recommended raw beef hamburger. Have you ever fed yours that ? Is it a safe alternative ? I live in an area where our options for frozen food are limited. <Raw beef is not even remotely a safe or sensible foodstuff for a BGK (Apteronotus albifrons). Wild fish feed almost exclusively on small invertebrates, specifically worm/insect larvae type things and small crustaceans such as Daphnia. They don't really eat fishes, let alone meaty foods. So, with that in mind, your existing diet sounds just about ideal, so why not stick with that? Treat them to some live daphnia or brine shrimp when you get the chance, or "grow your own" midge larvae in the garden if you can. But otherwise, stick with what you're doing. There's a specific problem with feeding beef to fish, and that's the fact fish are cold blooded. Warm blooded animals use lipids that are oils at (warm) body temperature, so flow, but become fats (i.e., solid) at lower temperature. In short, feeding meat from warm blooded animals to fish is, with a few exceptions, an invitation to clog up their digestive systems and circulatory systems. Not good. Beef heart is sometimes used to feed fish because, being cardiac muscle, it doesn't contain any fat or oil. But other types of meat, especially muscle meats, are just NOT SAFE.> Thank you for any help or suggestions you may have to take care of our beautiful ghosts. They are a joy to own and raise. Sincerely, Rebecca <Cheers, Neale>

Feeding a Black Ghost Hello, <Hi back! MikeD here>     I am a very new aquarium owner.<Welcome to the wonderful world of fish addiction, er, keeping.**grin**>  I am obviously still learning about everything.<50 years later, me too. The learning never stops>  I just found your site yesterday and I'm loving it!!  But I do have a question regarding a black ghost knife that I bought about 3 days ago.  I currently have a 60 gal. tank with 2 parrot fish, 2 black skirted tetras <In the future tetras and often barbs, do better in schools of 5-6 rather than in pairs> 2 catfish, 2 angel, 2 Gourami, and now I just added the BGK.  Is this too crowded??<Not necessarily. My biggest concern is did you give you tank enough time to cycle, and/or that you added all, or most of your fish at one time.>  I am feeding pellets and flakes to the other fish, and got some frozen bloodworms and shrimp pellets for the BGK.<This may work, but some ghosties can be a little demanding on food choices, especially when they are first obtained>  I feed them around noon everyday.  I understand the BGK is shy<Not shy, nocturnal, which are two separate things entirely>, but he will not come out of his hiding spot when I feed the tank.  My other fish not only eat all the flakes and pellets, they also eat the bloodworms and pellets.  I'm afraid they are not leaving anything for the BGK.  Do I need to change my feeding time or habits??<Yes, the Black Ghosts are nocturnal nighttime animals that often are very reluctant to come out into the open during the day. Usually, this will gradually wear off in time, but early on the best thing to do is feed it separate, just after turning off the lights at night. You might also want to keep check and make sure that it's eating what you are offering for food.  The bloodworms will almost certainly be eaten, while the pellets are a big if for now, possibly forever.  They also relish raw shrimp (either cut up pieces of human food shrimp or the small live ghost shrimp sold as feeders in many shops) live or sometimes freeze dried Tubifex worms, daphnia, etc.. Their absolute favorite food is live earth worms like you'd use for fishing!  Some will gradually start consuming "normal" aquarium fare while most others are always somewhat demanding and require special foods>   Thank you for your help and information!!<You're welcome and I hope this helps...the Ghosts are one of my all time favorite freshwater fish species> Mike

Another Black Ghost Knife Question I Have a Black Ghost Knife 4", If I put on my Aquarium light (which I haven't turned on  since I had him, 4 months) will it stress him out or kill him well because they hate light and are nocturnal)? He does have this ornament with holes in it that he goes in and out of (prefers that then the ghost tube), can he be in there if the light is on? < Black ghost knife fish are nocturnal and should have a hiding place to retreat to when the aquarium light is on. They should be fed just after the lights are turned off.-Chuck> Thank You Jahner

Black Ghost Knife Feeding Hello fine fishy folks, GREAT website.  I have spent hours and hours here for the past couple of years and learned more than I ever thought possible.  Thanks for the effort you all put forth. I have a simple (probably paranoid) question for you. I have had a Black Ghost Knife (Apteronotus albifrons) for the past 2 years and he is a big boy!  Looks great and is my favorite fish.  He is health, velvety black with brilliant white markings on the tail (starting to fade on the head - from age?).  He is currently sharing a tank with 3 clown loaches, 1 fire eel, and 2 black kuhli loaches. My question is, what I feed the tank is Tetra flakes and shrimp pellets in the morning, and frozen cube (thawed of course) enriched Mysis and frozen blood worms in the evening.  Since the BGK is approximately 14 inches long, is this fare big enough for him to get enough to eat?  Should I try switching to larger shrimp/worms, etc.? Any input/opinions you care to share would be much appreciated.  I am probably just being paranoid, but can't stand the thought of him being hungry all the time and risk slowly starving him. Thank you and keep up the good work! Tom <<Dear Tom; What a great job of fishkeeping you are doing there! Your ghost is large enough to warrant more food, yes. Keep in mind this usually means more water changes :P You can try a few new things: Earthworms are a great source of protein, bought from your local fish 'n tackle bait store, or you can grow your own http://www.thekrib.com/Food/, live ghost shrimp from your LFS, chopped seafood from your local grocery: buy frozen shrimp, etc, and chop into bite sized pieces for him. It's also a good idea to soak your sinking shrimp pellets in some liquid fish vitamins, like Selcon or VitaChem (also sold at pet stores) so he is getting a decent staple. Have fun! -Gwen>>

Training a black ghost knife fish  9/22/05 Dear Mr.  Fenner, I have a black ghost knife fish that I have had for a month.  He is now about 7" long and very healthy.  He eats flakes in the morning and at  night, occasionally I give him some freeze-dried Tubifex worms.  What I  would like to know is how you teach them to eat out of your hand. He seems to be  a smart one he figured out the flakes were edible on his own.  If you know  how to do this I would really appreciate it. Thanks for your  help, MDM <Try feeding small amounts of meatier foods, more frequently, particularly just with some light on outside the tank (not in... too bright). Takes time, patience. Bob Fenner>

Black Ghost Knife Feeding Have you ever known a Black Ghost Knife to eat flake food because odd as it sounds mine just did... usually feed him on freeze dried Tubifex worms and brine shrimp and was shock not only to see him come out in the light and feed but to snag some flake away from my Gouramis and clown loach. <Have seen these intelligent fish eat most everything... do need meaty foods to sustain themselves though. Bob Fenner>

Black Ghost Knife Won't Eat I bought a black ghost knife  week back and gave it a small place to hide. Since then it has been hiding inside and very few times, twice in fact, it came out in the night. Apart from this it does not eat anything. I feed it in the night to discover that the food is still floating in the morning. Will it take time to get set in the tank or is it sick? There were small molly fry in it which  I bred and it has not touched them. Is there anything wrong with it ? Is it a strong or a delicate fish? I do water changes once a week. Pls advice <Your black ghost knife fish is indeed a nocturnal fish. Try small live invertebrates live worms or shrimp. After awhile you may get him to try frozen foods and then maybe pellet foods. If you can get him over to prepared foods then keeping him will become much easier. If you can't then live and or frozen foods may make him difficult to keep.-Chuck>

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