Animal Stories - Black Ghost Knife Fish

Animal-World Information about: Black Ghost Knife Fish

The Black Ghost Knifefish is the most well known species of knife fish in the aquarium industry!
Latest Animal Stories
Gina - 2012-05-10
I have bought 2 bgkf and I have a 125 gallon tank. Both fish have died within a day of me buying them. I have 2 red tips a black shark and a rainbow shark. My water always tests fine pH is 7.0. I am confused and disappointed. I don't know what's causing the fish to die. Any help would be nice.

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  • Jeremy Roche - 2012-05-11
    Could be the place you got them from. How did you acclimate them to the tank? They stress very easy so a slow acclimation is best.
  • Anonymous - 2012-05-11
    I allowed the bag to float for 15 minutes and than released them into the tank. They were active and found a hiding place. Next morning they were fine and a couple hrs later they died.
  • lauren - 2012-07-19
    Try buying them from a different place.
  • Fred - 2012-09-01
    Maybe cause there was two of them, they couldn't really identify anything cause they were both sending electrical waves that kept intercepting the others.
  • peggy - 2012-10-13
    i had gotten my first black ghost knife from petsmart on sale for 8.60 somethin like that anyway he died two days later also bought other fish and put them all togather i noticed an outbreak of ick so i treated with ick- out he must have died from that i took him and the others to be replaced and got a big run around like they didnt want to exchange for another id wasnt takin no for the answer now two days ago once i brought new one home along with others i exchanged but did not put them in the same tank since im battling ick from the outbreak from the fish i brought home that also killed my few others i had in the tank a few months before i bought the black knife and others from petsmart anyway i put the newer fish in i exchanged in a qaurintene tank 20 gallon just untill the ich clears from my 30 when i put him and the other fish in the qaurintene tank i noticed white spots on them so i put ick out in right away and the next day spots seemed to be almost gone but i lost the ghost knife , i geuss ill be takin him back and exchanging him im sure with alot of disagreeing i did call next morning to petsmart in benton harbor, mi and told them about the ick and they probley have it the guy said he diddnt but i know they do but he told me to pick up some thing called ick-attack by kordon wich cost 11.00 so before i exchange themim makin sure the ick is gone but other then that can someone please e-mail me on what i can do better or whatnot so i can enjoy the black ghost knife for a long time my e-mail is thanks and im sure ill get grief from petsmart takin back the ghost knife for the second time within 3 weeks but oh well its not my fault for the outbreak they will just have to replace him, so here is my story of my losses hopefuly no more after this woud be nice so i geuss im not the only one out here that has lost a ghost knife but maybe two wich i believe it the stores of there non knowledge of ick in there tanks that customers dont kow about or them for that matter, peggy
  • MsMonique - 2012-11-06
    I bought my first Black Ghost fish about a month ago from Petsmart and I fell in love, however about 2 weeks later I could not find it in the tank. I have a 150 gallon tank and I looked everywhere in the tank and cold not find it. No remains indicating he was dead. I just recently bought 2 more less than a week ago and they seem fine. You do have to watch the fish you get from Petsmart. I suggest not purchasing anytime from Thursday thru Tuesday as they get a new shipment in on Thursday and therefore you run the risk of disease and the fish being stressed out from the shipment. I experienced 2 bouts of ick from my fish there, before I realized it was best to have a quarantine tank set up for new fish and not to buy fish when they first get them in. I did however by my ghost fish 2 days later only because they don't keep them more than 2 days in stock due to the high demand. Thankfully my 2 have survived for 5 days today. Good luck!!
  • Breezy - 2013-03-16
    Ick is due to stress. All fish carry the ick virus, it's when they are stressed it comes out. It's like a common cold for us. Immune system is down bam we get sick. To blame it on pet stores is ridiculous. It could have been the stress from being transported to your tank,or the stress of being shipped to the store. you should be checking the fish out before you purchase it anyways, never rely on someone else even if they claim to be 'experts.' When medicating you should use half the dosage because they are a scaleless fish they cannot handle a full dose.
  • kye turnbull - 2013-04-04
    White spot is not carried by all fish! A parasite, ichthyophthirius multifilliis, it comes on plants, fish that have it, gravel or water! It's not in every fish!
  • kye turnbull - 2013-04-04
    Although you are right about the scaleless dosing.
Anita Nyhus - 2010-10-20

I was just reading your information about the black ghost, and I would just like to give a small update -
We bred this fish in our tank a couple of years ago, truthfully, we got lucky and we were quite ecstatic to find we had managed. At the time we thought we were the first ever to have bred these fish, but it turned out a guy in Finland had done it before us :)

However, also a tank owner in Queensland, Australia has been able to keep two babies.

Our little guy was found behind the filtration map, as the egg had been sucked in – there he developed without any disturbance, and so was the only survivor.

The male of the original breeding pair died, and the female was given away to another black ghost owner, and we have not had them for a while.

Only weeks ago, we bought ten black ghosts, so hopefully we will manage again. We keep them in 520 liters tank, with sand on one side and gravel on the other. Many roots and rocks, no surface plants, and give them lots of food, preferably red mosquito larvae.
The filtration is very strong, and I reckon we were "lucky" when the egg was sucked in. It could develop undisturbed on the back side of the "back to nature" background, where the other fish never entered.

I am sure there are several others that can now report that they have bred them, but at least I can guarantee you that it has been done :)

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  • julie - 2010-11-07
    We have a tank (75 gallon) and We had two ghost knife fish... who are very happy with their environment. And at the moment we have 9 offspring of different ages. Its getting to the point where we need to sell some!
  • tHyNOx - 2010-12-02
    Wow! How lucky you are.. how I wish I could do so too.
  • hanzo - 2013-02-08
    How did you manage to breed ghost knifes? We have one about 8inches long in a 5ft by 2ft community tank. They are my fav fish in the whole world and i would love to breed them =)
blackghost - 2013-02-13
Just to clarify.... 1) BG Knifes also have a dorsal fin which is kept lying in a groove on the back 2) the anal and caudal fins are NOT fused 3) THEY ARE NOT SCALELESS

D@rkPr!nce - 2012-12-23
I have a black ghost knife about 12', an silver aro 22' and a pair of full grown parrots, in a 125g, the parrots r about 5+yrs old, what else can i put in.. I was thinking of Stingray, n moonys, kindly suggest some fishes.. Thanks a ton, in advance.. :D

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  • Jeremy Roche - 2012-12-23
    That tank is maxed out.  The arrowana is going to get huge!  A bottom feeder like the stingray would normally work but with these messy fish it would be extremely difficult to keep the water conditions right for the addition.
mahesh - 2012-11-06
I have bought two bgk fish but i am Confucius which one is male n which one is female how to know this they are 3.5'

chris - 2012-05-26
i bought 2 BGK fish, both about 5 cm (2 inches) they look fine but I am not sure if this is normal. One during the day just lies next to a plant not moving at all. I always think it's dead so I knock on the tank to be sure. I think it's just sleeping or something since it's a nocturnal fish. At night it's very active it swims all over the place but the other BGK stays in a pipe I put in the tank all day an night just swimming in the same place unlike the other one. Are they ok? My tank is 9.25 gallons (35 litres)is that ok? and how long does it take for them to grow to 15 cm(6 inches)?

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  • lauren - 2012-07-19
    They get BIG like 18 to 20 inches in captivity and need a large tank. They are not super active swimmers they need probably a 50 gallon or more.
  • Eryn - 2012-10-29
    10 gallons is not even close to big enough for one of these fish, much less two. They are small now, but they will grow quick (even quicker if they are fed a high protein diet). You need to upgrade to a 50 gallon (minimum), or find a new home for these fish, before they get stressed out and die.
J - 2012-09-27
Perhaps a better question would be, is a 4' clown loach safe with a 10' Black Ghost Knife BGK?

J - 2012-09-27
I have 7 1'-1.5' Clown Loaches and 5 2' Weather/Dojo Loaches, with a 2.5' BGK. They are more then happy now, but I know loaches are slow growers, especially after 4-5'. Will The BGK outgrow the Clowns and Dojos, or should they all grow about the same rate to be safely tanked together? Please let me know. If not I will take BGK back to the store (deadline for return is in 6 days) and wait a year to give my loaches time to get a head start on growing. (PS tank is 80 gals [planning to upgrade to 200] with over 800gph filtration and a 320gph water pump and 2 air stones). Thanks for any advice!

sonja - 2012-09-25
My ghost fish means the world to me. As my kids call him puppy dog he loves his blood worms, I would just like to know how do you learn them to eat from your hand .

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  • Jeremy Roche - 2012-09-25
    Use forceps or tongs and dangle in front of the fish.  Bring it closer to the surface as the fish gets use to it.  I would not recommend using your fingers.  Humans carry germs and bacteria that is not good for fish.
BEV - 2012-08-04
I have had my ghost fish for many years, recently he has started turning white, is this a disease?

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  • Clarice Brough - 2012-08-05
    They do have a more silver 'nocturnal' coloring. Fading is also attributed to a water chemistry change (often a pH change), so recommendations are to start with a 50% water change.
  • Clarice Brough - 2012-08-05
    Also, here's a bit more from my research. Besides water conditions, Bob Fenner says ( 'poor water quality, stress, age, diet, there are many things that can attribute to these fish changing color'