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Main Index > Detailed Fish Profiles > Miscellaneous species > Black Ghost Knife Fish
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This page will give a completely detailed profile of the selected fish, from A to Z. The profiled fish will be chosen randomly by Badman, and will come from the complete genre of tropical fish. New profiles are added on a regular basis. If you would like to submit a profile for the site please contact me. Don't forget to let us know you experiences with this fish by filling out the

South America



Apteronotus albifrons



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Please remember that the following comments are personal experiences and may or may not apply to your setup. Use them as guide to help better understand your fish, like us all individuals will behave differently under different circumstances.


We have had our Black Ghost for 9 months now. He is certainly growing on a steady basis. He gets feed bloodworms, brine shrimp and flake food. I wasn't sure about getting him because I thought he might be a hard keeper. Boy was I wrong. "Ghosty", (I know not very original) lives with a very large variety of fish. I was very surprised reading on this web site of them eating other fish. I have never had that problem with him, even when we put a few very young sword tails in the tank. He is so much fun to watch. I going to have to start feeding him by hand, I bet that is a blast.
From: Corey
I Have a Black Ghost Knife Fish that is about 8 inches long. I have it with a Iridescent Shark, Two Angels, A Silver tip shark, 4 Platys, and one Molly. So far I am pretty certain that the Ghost knife has eaten the molly, one angel, and the silver tip shark which was 5 inches long! I have not seen him do it but I for sure it is him. I have a problem with the ammonia in my tank, so I have been going to feeding them every other day. The days that I do not feed them I wake up to a faceless casualty. I believe that if you keep them fed every day you will not have a problem but forget one day, and you better just say good-bye to someone!
From: Leo
We have had a black ghost for nearly 6 months. He has grown to be about 10cm and he spends most of his time hiding in a hollow log or underneath drift wood. He seems to enjoy eating frozen bloodworms and occasionally sinking pellets. We believe that he has been our silent killer of neon tetras, rummy noses, baby bristlenoses and cardinal tetras. Everytime we purchase 10-20 of these little fish to create a pleasant school, within days the numbers drop to nothing. We have discus, angel, tiger barb, silver sharks, gouramis large bristlenose, a few sucker fish and a 20cm freshwater eel. All other fish are fine. I recently went to a pet shop and asked who might be eating out little schools and the lady definitely said it was the ghost. She said they "suck" their prey and they actually have a very large jaw that opens wide. Any small fish that is streamlined and able to fit into their mouth, can be mistaken for a easy meal. She suggested to look late at night with a torch and it is possible to catch the ghost in action! She did this when she lost about 40 tetras is 4 days! Our ghost is gorgeous but we don't think we'll ever have little fish again.

From: Gayle
I owned a Black Ghost for 5 years. He was about 8" when I got him and grew to at least 13" before he died. I have no idea of his age. I did weekly or biweekly water changes. I would check the Ph & hardness/softness monthly. I rarely had to make adjustments. I use town water. The tank was a 30 gallon with dense plants and rock hideouts. We had a clear plastic tube that he would hang in. He would also eat out of my hand if the mood and the food was right for him. I fed freeze dried brine shrimp, cubes of krill type food, pellets and flakes. I am now getting a 75 gallon tank and I'm searching for another Ghost. I also found they got along with any fish that was non-aggressive. I never had any problems with the Ghost killing other fish, even the small neon tetras. They have become my favorite fish after many years of owning fish.

From: Phyllis
I have owned this fish for 4 yrs. 'He' is 9" long and eats from my hand. I do partial water changed weekly. And never check any ph or dh levels. He is growing and seems very happy. He shares a 29 gal tank with 4 black fin tetras, a plecostamus and glass catfish which were purchased at the same time as he was. All other gouramis etc introduced seem to die. He never has shown aggression but who knows what happens when the lights go out. I transported the tank with occupants,200 miles to gave the tank to my son who did nothing except feed the fish for one year. I reclaimed the tank and it has taken 3 times to get the tank cleaned up without too much disturbance. He doesn't seem to like the disturbance of his cave areas. The original occupants all seem healthy and happy(probably happy to see through clean water again). After a couple of tries the knife (Finley) is back to eating out of my hand again. I think they are a very durable fish. Mine is both friendly and elegant, a joy to watch....and I used to think fish weren't viable pets.
From: Sarah-Jane
I bought two of these fish for my community tank about two months ago and they are such a beauty to watch. When I bought the first one he was really shy so got him a playmate and they both now swim around the tank confidently sniffing around for food constantly the way they do. Very busy little creatures indeed. They get along very happily with my other fish, guppies, black widow and neon tetra, clown loaches and glass shrimp. I found they love lots of plants, hidey-holes and places to explore. I am no expert but I keep my tank at a perfectly neutral ph and fresh water changes regularly. Mixture of foods gives variety such as bloodworms, flakes, I like live brine shrimp as it gives them a bit of a thrill to chase them :)
From: B.Mortimer
Me and my boyfriend have only recently become interested in the keeping of tropical fish after receiving a fish tank as a present. The Ghost knife particularly caught our eye as we observed the many fish in the local pet store. We finally decided on the Ghost knife, two angel fish, two bristlenose's, a coolie loach and a red-tail shark, all of which were small babies at the time of purchase. I came to the conclusion, only in a few months of experience, that the Ghost knife works well in a community. I thought this right up until it began to grow rather large quickly and the smaller bristlenose's we had were suddenly nowhere to be seen. We feed the Ghost knife daily with bloodworms which he really enjoys but we were puzzled to find after completely clearing the tank out that we had no longer have any bristlenose's. He is now around 10cm and is aggressive to the smaller occupants of the tank which have now been removed we believe he ate them. When I read one of the comments saying there not aggressive I was puzzled as I believe they can be.
From: Chris
My Black Ghost Knife, Lightning, is an endless source of entertainment and the feature fish of my four-foot tank. He is still quite small and so far as grown very slowly, getting along peacefully with all the inhabitants of my tropical tank, including dwarf gouramis, several small tetras and cory, upside-down and bristlenose catfish. I feed him frozen brine shrimp and bloodworm, and meat mixes like beef heart. It took about three weeks before he was bold enough to eat from my hand, as these are naturally a very shy fish, but once tamed are very entertaining and will weave through offered fingers. They also swim in any direction, including backwards and upside down. Being mainly nocturnal most activity occurs at night, spending the day in hiding. Favourite shelters include tubes of hollow driftwood and rocks with passages through the center, but he is also fond of some of the broader-leafed plants and will lurk between the fronds, often visible only by the gently waving white tip of his tail. I've planted my tank with several large lillies, which have spread over surface of the water and keep low light levels to encourage activity during the day. Interestingly, Black Ghost Knives have a mild electrical current and are also classed as 'scaleless fish', so halving the dose of any medication used when these guys are in residence is recommended.
From: Chad Kelly
I have been keeping this species for over 15 years in mixed communities. Contrary to many of the write-ups I see on the Internet, over the past 15 years I have never had one of my Ghost Knives show aggression towards even the smallest fish in any of my tanks. All of mine have been very docile and I hand feed them. I have found them very attracted to bloodworms and frozen shrimp. Without exception, hand feeding these foods to them has made them very personable to the point of laying in my hand while they eat out of the other. They prefer to be secluded in a cave approximately twice the diameter as they are tall, and long enough so that they do not have to stick neither their head, nor tail out the ends. Clear tubes look like they should work fine in the store, but you will find that they will always prefer to be in something dark. I have some pictures of the PERFECT Ghost House that without exception, all my Ghosts have taken to. You can tell how comfortable they are by their behavior when in it. A happy home will make them actually lay down in it and relax, swim upside down, and generally frolic inside of it. I wish I could post up a pic here so that you could all see the perfect home I have found for them. Regardless, I have one that I have had for over 9 years, and appears to be just a frisky as he was when he was a fry. Above all other fish, I find this species to be the most interesting, most beautiful, and most compatible in the hobby.
From: Todd
I love this fish. I've had mine for 4yrs its 10" long and seems at peace with the other fish ( 1 angel,2 silver dollars,7 sm.zebra tetras and 3 chubs)in my 55gal tank, which is decorated to replicate a streambank. The dense environment of drift wood,replicated tree roots, plants and the submerged faux stone background with multiple caves and crevice's looks cool and allows the ghost knife to weave its self through the tank in its mesmerizing fashion. I feed my fish frozen brine shrimp(3 cubes / a.m.) & blood worms(3 cubes / p.m.) and a couple of sprinkles of flake per day. This fish is elusive and sometime I have to hunt for it. One way I found to trick the ghost knife out is to place window tint under the bulb to defuse the intensity of the light. I keep my tank fairly dark with holes cut in every so often to allow in shafts of light,this keeps down the algae and aesthetically looks more realistic. Also allowing me do get rid of the interesting but messy plecostomus. I would also highly recommend a timer for your lights, if you don't have one already. Its been my experience that the better I can replicate a natural enviorment the more success I have.Enjoy
From: Hop
The Black ghost knife fish (Apteronotus albifrons)is a very entertaining fish that is long lived and grows to a fairly large size. Good hiding places such hollow logs and caves are must for Black ghosts to really feel at home. Water should be well filtered with neutral PH, and a temperature around 78 degrees. Feed these great fish a varied diet including live foods. Mine really enjoys small earthworms and blackworms. Avoid giving them guppies or small feeders as it has the knack of introducing disease. Large, "Peaceful" fish that can handle themselves do best with Black ghosts.

From: Ridwaan
My ghost knife is already 28-30cm long and what I've noticed is that it gets more and more beautiful as it grows. The white on the body becomes more visible and it does get aggressive with other fish trying to come inside its hiding place. My ghost eats only high protein pallets and the way it swims during feeding time is the best experience for the aquarium lover. My ghost lives along with my 40cm silver arowana and 30cm giant pangasius. They are getting along very fine because they were put in the tank at the same time.They grew up together.
From: Steve
A wonderful fish with an entertaining way of swimming. They move by waving the long fin along their side up and down in an almost hypnotic motion and seem to enjoy swimming backwards as much as forwards. Often they will locate their food by swimming backwards over it and gobbling it up as it goes by their mouth. They spook easily and love a good dark spot to hide in, where they will hover for long periods. My favorite thing about these gentle fish is that once they are comfortable with you you can feed them by hand. They will even wag their head out of the water to nibble fish flakes from your fingers. In this way you can gently handle them (perhaps they like the electrical sensation they pick up from your fingers?) They occasionally fuss with other bottom dwellers who attempt to invade their favorite spot. They grow slowly but seem relatively hardy. Don't keep other aggressive fish around them or they will stay hidden which is a shame.





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