I thought I would post an article about my personal experience with The Black Ghost Knife fish, when I was working as a pet store manager.
Thirty years ago the Black Ghost Knife was a “new fish” for the pet trade. It was a stunning, velvet black and we marveled at its unique way of swimming sideways, backwards and sometimes standing on its head. At the time we also were getting Clown, and Brown Knife fishes in stock for sale. But the Black Ghost was the one for me. The dramatic black with a white blaze down its little face and white rings on the tail were what I dreamed of having in my own tank at home.
Our fish room manager told me he could get me one and ship it out with my next store order. So when Friday came I was pretty excited to have receiving call me and tell me I had a van on the loading dock asking for me. I told receiving to let him unload that I was expecting a shipment of fish and birds from the home office in Atlanta.
I began unpacking boxes and floating bags of fish to acclimate them to the water temperature of their new homes. Then I found my fish and he was a beauty. He was in his own bag and shipped very well, his color was good and he was large about 10 – 12 inches. I took him home and floated him in one of my 30 gallon tanks while I found a wide mouthed carafe to put in the tank for his new home. The knife fishes do not see well and operate on their sensory organs. They do produce weak electrical currents but these are for “seeing and knowing their surroundings rather than for killing prey”. The knife fish must have some sort of cave to feel safe but he will never know the difference between a transparent cave vs an opaque cave.
I let the knife fish settle in and fed the few other fish in the tank. The next day I began working with the fish to feed him. Knife fish like live foods such as worms and small fish, anything that will fit in his mouth is fair game. The mouth kind of unhinges, similar to a snake when the fish takes food into its mouth. This unhinging action is most apparent with the Clown Knife fish. I was astonished to see how wide these fish can open their mouths.
I like to use Tubifex worms as most meat eating fish really like them and they are not expensive. The freeze dried worms come in a cube so it is easy to break of a bit and soak it in the tank water. As the cube soaks the flavors also begin to drift in the tank. I would hold the cube level to mouth of the carafe but far enough away so the fish could come out of the carafe and not strike its body on the carafe. It took about 3 days and the fish soon learned when I put my hand in the tank I probably had some food for him. He eventually learned to come right on out of the carafe up to the top of the tank to eat out of my hand.
I greatly enjoyed working with him while I had him. I say him but it could have been a female. We certainly did not know how to sex them in 1984 so that will always be a mystery. If you are ever interested in setting up a tank for a knife fish just remember to use a larger tank 29 to 30 gallons is the smallest I would want to go. A 55 gallon would really provide a nice display. If you want to know more about the Black Ghost Knife.