Knifefish - Few Questions.

[Wills]

Hi just bought a 6x2x2 and one of the fish I 1000% want is a knifefish. The one I really want is Parapteronotus hasemani aka Dragon knifefish but I dont think I will ever be able to source one. Unless anyone can point me in the right direction?

So that leaves me with 2 options that I am interested in -

1. Black Ghost Knives - first question how many in a 6x2x2 just one or could I do 2? Obviously I know its based on total stocking but just as a kind of blue sky situation. How active are yours or any that you have kept I have seen quite polar opposites with some peoples like some are really really timid and never come out where as others are all over the shop.

2. Glass Knives - I read they are best in a group? So I was thinking three or four? Dont know a great deal about them so any info would be greatly appreciated, one of my favorite LFS has quite a large batch in at the moment so I think getting some wont be too much of a problem

All help greatly appreciated

Wills

 

[mike_980]

i have a single ghost knife in my 110 liter at the moment (will be upgrading to a similar tank to you when he outgrows it) from the research i did i found its unwise to keep 2 together but 3 or more or just the one, personally i would go for the single one to save any risk of aggression to each other as you never know with these fish because in my opinion everyone is different just like with humans

im sure youve done your research but they need plenty of hiding spots, i prepared my tank and gave it plenty of shelter before adding it but its been 100% friendly since day 1 and is out mixing with the other fish day and night! i probably just got lucky though

amazing fish i would highly recommend them!

heres mine

all the research i did claimed they only really eat frozen or live food but mine eats everything and anything! everytype of flake and frozen i have offered so far, cucumber and peas (video to prove it!) also proving everyone is defferent! get a BKGF you will not regret it


also one thing i did read is that the more hiding spots there are in the tank the less likely they are to be shy if that helps!

 

[simonas]

I would say go for the black ghost inthat tank

You;ll seeitmorethan the glass knives and will be easier to feedas they are absolutelygluttons!! They are acracking fish which looks great inmost tanks they grace

 

[nmonks]

Glass knives are superb fish, and really impressive when they get to their adult size of around 25-30 cm. But you'll need more than 4; get at least 6, and ideally more than that. Like all electric fish they are hierarchical and in small groups bullying is common. Here's what I said about this species in a TFH article a year or so back:

Knifefishes are often social animals, and within the group there is a whole repertoire of signaling that depends on electricity. Male and female glass knifefishes (Eigenmannia spp.) produce their electric pulses at different rates. It turns out that the status of the individual within the group determines is reflected by the rate at which it emits electrical pulse. The dominant male ‘buzzes’ at the lowest frequency, the dominant female at the highest frequency, and all the others somewhere in between, depending on their gender, rank and maturity.

Sometimes aggressive or dominant individuals will deliberately adjust their frequency to ‘bully’ subordinate individuals. By interfering with the electric sense of the weaker fish, the aggressor effectively ‘blinds’ it, making its own superiority clear. But most of the time the sociable species take care not to jam one another’s frequencies, and carefully maintain a 10-15 Hz gap between their personal discharge frequency.

The glass knifefish seen in the trade is usually Eigenmannia virescens. It is gregarious but feisty, so you need to keep at least six specimens to avoid problems with bullying. They can get up to 12 inches (30 cm) in length, so while these are not bulky or messy fish, they will to be kept in a reasonably large aquarium.

Wild fish inhabit both still and flowing waters, and under aquarium conditions seem to be fairly adaptable. A spacious aquarium with plenty of plants, particularly floating plants, is essential, and the water quality should be good. Like other knifefish, they consume a variety of small animals, including fish, but in the aquarium live or frozen bloodworms and other insect larvae are readily accepted. They also enjoy earthworms, daphnia and brine shrimps. They are best kept alone, and can look superb as the sole midwater fish in a planted aquarium, though they could also be combined with fish unlikely to steal their food. Hatchetfish for example would be ideal, as would slow moving bottom dwellers such as Ancistrus.

Cheers, Neale

2. Glass Knives - I read they are best in a group? So I was thinking three or four? Dont know a great deal about them so any info would be greatly appreciated, one of my favorite LFS has quite a large batch in at the moment so I think getting some wont be too much of a problem

 

[Wills]

Thanks guys

Simon - I really think I will end up with a BGK, I remember when I was a kid and I saw my first one ever and I was just like wow I had goldfish at the time but they were one of those fish that made me want a heater

Neale - Thankyou as ever really appreciate that! The TFF website is really a fantastic resource now have you thought about trying to use some of your articles to update this forums tragic profiles? Just a thought But as far as the glass knives go - I am keeping cichlids - mainly peaceful things like sevs and geophagus but the main aim is the cichlids so I am starting to think of a more easy care knife like the BGKF or perhaps try and source one of the rarer ones that you see about from time to time.... Do you have any suggestions for a suitable knife that is quite robust but still quite active and attractive and also attainable haha

Thanks again Wills

 

[nmonks]

That excerpt was actually from TFH Magazine rather than the TFF web site, but either way, thanks for your kind words.

I haven't noticed any real problems in the forum profiles. Sometimes moderators pass the oddball ones past me for comments, but if there are problems with the forum profiles I think perhaps talking with the authors would be a good idea.

Glass knifefish wouldn't be an obvious choice for use with cichlids, though I dare say Bolivian rams, flag acara or keyholes would be fine. Electric fish tend to be ignored by other fish, and provided the cichlids aren't aggressive or nippy, there shouldn't be any serious problems if the tank is big enough for all concerned. If you're after a one-off knifefish for a robust community tank, Xenomystus nigri is the pick of the bunch. It's essentially peaceful, though territorial, and tends to ignore other fish too large to eat. Unlike the electric knifefish it's basically a glorified carp in terms of physiology, so there are no real headaches in terms of water quality and the use of medications. It mixes great with West African dwarf cichlids, South American cichlids, Congo tetras, Synodontis, and various other fish. Provided water chemistry and quality were suitable for geophagines, I can't see any problems mixing them.

I will note that many geophagines appreciate relatively cool, well-oxygenated water, and as such would be good companions for Apteronotus species. But the problem with these knifefish is their longevity in aquaria isn't all that great. Lots get sold, but you don't see many living for 10-20 years and reaching their full adult size. Keeping them too warm and in tanks without enough oxygen is surely part of the problem, but that's the same with geophagines, so it could be a match made in heaven.

Cheers, Neale

Neale - Thankyou as ever really appreciate that! The TFF website is really a fantastic resource now have you thought about trying to use some of your articles to update this forums tragic profiles? Just a thought But as far as the glass knives go - I am keeping cichlids - mainly peaceful things like sevs and geophagus but the main aim is the cichlids so I am starting to think of a more easy care knife like the BGKF or perhaps try and source one of the rarer ones that you see about from time to time.... Do you have any suggestions for a suitable knife that is quite robust but still quite active and attractive and also attainable haha

 

[Gytas]

i sow some knifefish in my local pet shop the other day and i think they look really really cool i would love to have some but my tank would be too small and on the tank that they were in it had a piece of paper on it which said SOLD so i guess some1 got there before me

 

[Flagtail]

Go for the black ghost knife. He'll be the coolest knife to own.
I have a 6-7'' bgk. He is one of the most personally knifes I have ever owned. He knows when I do feedings. He comes right up to the tank and lets me put a piece of tilapia in his mouth. Plus, he is one of the most active fish I have ever had the pleasure of owning. I mean he will hide with the lights on, but when the lights are out he is out and about. Really cool fish glad I got him.
BGK max out at about 20-24''. Although the biggest I've seen around me is 18''. They have a good growth rate. Bought my guy at 2'' back in Feb and now he is 6-7''.
BGK will eat mostly anything. But they seem to love frozen bloodworms, tilpia, shrimp, flakes, the occasional guppies, and earthworms.
BGK need to be provived with a cave so they feel safe. But at night they are out and about.
Tankmates for the BGK include other larger community fish. Uarus, severums, geophagus, other C.A and S.A Cichlids will work as well, silverdollars, bala sharks, flagtail prochidulois, catfish, etc.
Keep me posted!

As you can tell, I love BGK!
-Flagtail