Anyone into knife fishes?

Post by **Marc van Arc** » 25 Apr 2007, 18:05

With regard to the South-American knife fishes I only have experience with Apteronotus albifrons (black ghost) and the electric eel.
Is there anyone around here who could provide some information on the keeping of Rhamphichthys rostratus aka Bandfish?
Thanks.

apistomaster · Post by **apistomaster** » 25 Apr 2007, 21:11

Hi Marc,
I've kept Black Ghosts, Green Glass, 0ne 30 inch electric eel and had a pet Carapo Knife which was one mean sob.
Haven't ever kept the long nose knifes but I would make sure I had a supply of live worms on hand. Might make a good tank mate with a SA sting ray?

sidguppy · Post by **sidguppy** » 26 Apr 2007, 07:54

I din't think Marc would fancy a stingray; that tank's full of wood and Auchenipterids who hide in it.....stingray-tanks should be almost void of wood or very very large.
they need a LOT of space to move around on the floor, wich means you have to have an open sandy floor. that will not please all the driftwood-cats.

btw Marc if you get those knifefishes, I think I speak for many that we want to see pics!
that's a quite unusual species you mentioned.

As you know I tried Eigenmannia in the past, but they didn't fare well.
quite fragile when it comes to high summer temperatures, needs a LOT of food, because for some reasons they have a very rapid digestion.
they reminded me of pufferfish for that very reason.

tricky with all those catfishes in there, fierce competition over the food.

I've had bad experiences with fast-digesting shy non catfishes in catfish-tanks, recently with the combo spiny eels Vs Synodontis. a spiny eel behaves a bit like a knifefish IME. it needs quite a bit of food, it's shy and it doesn't eat as fast as a catfish.

I had to remove the smaller eels, they couldn't survive the Syndontis-feeding frenzy. the big one I handfeed, else it would starve. the smaller ones are now in a tank with Phyllonemus wich is far more shy than Synodontis. so maybe there's a comparison: if the Knife fishes are small you might think about adding them to a tank with less voracious feeders.

something to think about if the knifefishes are aimed at the big tank.

maybe not if they're small knife fishes and they will go to the smaller tanks?
but foodcompetitors will be a major issue here, more than hiding places or possible agression.
AFAIK those Auchenipterids you have at the moment aren't agressive to other fish.

apistomaster · Post by **apistomaster** » 26 Apr 2007, 08:12

Feeding would sure not be a problem with a carapo knife. They could hold their own with anything.
Nor are they delicate. They have remarkable regenerative powers. Serious predators.
Probably the only SA Knifefish that could cut it wth the big wood cats.

Post by **Marc van Arc** » 26 Apr 2007, 10:52

apistomaster wrote:I've kept a pet Carapo Knife which was one mean sob

Hi Larry,
Thanks, almost forgot that one. Gymnotus carapo has once been in one of my tanks for quite some time. It was with all kinds of mean catfishes, so it didn't really stand out of the crowd.
No stingrays for me I'm afraid. Not that I don't like them, but as Sidguppy said I need loads of wood for my Auchenipterids to hide into.
That should be a good environment for a long nose knife too, but I found out it'll grow to about 3 to 4 foot

. The local people seem to enjoy it as a food fish. So if I'm clever I should stay away from it. The question is whether I'm clever or not

Bas Pels · Post by **Bas Pels** » 26 Apr 2007, 11:47

I know someone who managed to have an open sandy floor, and a lot of wood in his tank. He hung the wood, instead op placing it on the sand. The bottom 10 cm was kept open, which turned out to be enough for the stingrays.

I wrote in the past, because he is now fully into cich lids, and does not have any stingrays any more. Thre cichl ids he has are too sensitive to ombine with them.

apistomaster · Post by **apistomaster** » 26 Apr 2007, 17:15

Hey Bas,
Suspending some driftwood sounds like an ide with several possibilities, have to keep that in mind.

Marc,

Don't you suspect the long nose Knifefish, if you can find one, might be a bit delicate and defenseless as SA Knifefishes go? That is my sense on them but of course, I've never had one.

I only mentioned stingrays as a more sedate tankmate but I know how much you are geared up for wood cats.

Actually the old reliable Black Ghost might still be the best all around fit in size and temperment.

Post by **Marc van Arc** » 26 Apr 2007, 18:29

Larry, Bas,
I've been there too in the past. The idea is brilliant and so are the looks, but when you have to work in your tank it's hell. Don't even think about getting a fish out of your tank quickly; before I unscrewed the first piece of wood all fishes had vanished into thin air. Because of that I've stopped with it. Might be good for someone who's very pleased with his fishes and thus doesn't have to change a lot.

BTW: it's no matter of if I can find one; I've found several. That's in fact the problem, because that triggers me to "save" them from people who may put them in a 60x30x30 cms....
Still in doubt however.

apistomaster · Post by **apistomaster** » 26 Apr 2007, 21:12

Marc,
Your point is well taken.
It would be an interesting experience to keep one of these and learn more about their care.

Post by **Marc van Arc** » 27 Apr 2007, 14:46

Larry,
Something you mentioned started me thinking. Even the Apteronotus had a hard time in the end, so I don't think it's wise to add an even more delicate species.
Thanks for the comments; I believe they saved me from a(-nother) disappointment.

apistomaster · Post by **apistomaster** » 27 Apr 2007, 16:41

Marc van Arc wrote:Larry,
Something you mentioned started me thinking. Even the Apteronotus had a hard time in the end, so I don't think it's wise to add an even more delicate species.
Thanks for the comments; I believe they saved me from a(-nother) disappointment.

Marc,
Always happy to come to the rescue. Still the opportunity to have a long nose knifefish, even if kept solitary, would be a very tempting prospect.
The whole group of SA knifefishes are understudied by aquarists although there has been much research done on there electrical field navigation.

I have had many Black Ghosts over the years but it has been awhile. You have gotten me started to think about it. Actually what I would like is the less spectacular brown ghost. I had a few long ago as stock passing through my old fish shop but I've never actually set out to maintain one over time. I know they aren't as sturdy as Black Ghosts but they do resemble the longnose knife at a fraction of the cost.
They are so "intelligent" a group of fishes as this is "measured."

Post by **Marc van Arc** » 23 Aug 2007, 18:27

Digging up this oldie to say that I've rescued the last of the Mohicans. This specimen has had a large tank for itself for several months. When the LFS owner asked me (again) to take care of it, I thought I might give it a try after all.
With regard to behaviour it fits in nicely in my tank: it doesn't move at all during the day.....Hope it takes care of itself during the night

Here are some pictures. The fish sits in a bucket, in order to see it. In a tank filled with wood and plants that's pretty impossible, for you'd miss it - even when it's right under your nose.

sidguppy · Post by **sidguppy** » 24 Aug 2007, 08:58

That is one weird fish.....but it looks almost exactly like the ones laying flat in the sand at Tropifish, ages ago.

same species?

with weirdo's like that, you might tryu handfeeding. or attach a piece of hose to a funnel; this is a great way to 'aim food' at a shy fish' hideout.
put the food (red mosquitolarvae for example) in a bit of water and pour it in the funnel; the hose gives you the oppertunity to aim it at the fish (I used this trick to feed a nest of baby fish in a community tank)

I use the smallest kind of waterhose (the one used on Eheim 2011 filters); a 1-1,5 foot long piece attached to a medium small funnel.

apistomaster · Post by **apistomaster** » 24 Aug 2007, 16:02

Hi Marc,
I'm glad you decided to buy the long nosed knife fish.
There isn't much information on their care so maybe you will be able to fill in some blanks. Too bad live black worms aren't available to you because they should be worm eaters. I would try some small garden variety earth worms on it. From what I have been able to find they do eat worms. I know Black Ghosts get so tame they will take small earthworms from your fingers once they learn to associate your hand with worms.

Post by **Marc van Arc** » 25 Aug 2007, 10:24

sidguppy wrote:That is one weird fish.....but it looks almost exactly like the ones laying flat in the sand at Tropifish, ages ago. Same species?

Yes, the good old days. If only we could turn back the clock....
I don't know if it's the same species. If so, it would have been pictured by Ruud Wildekamp, like he did with many more species that turned up in the Mergus series.
This one didn't so far, so either it's no species that TC has ever had or it will probably make its way into Mergus 7(when is that going to be published ?).

Your how-to-feed suggestion is appreciated, if only I knew where the silly beast hides. Have to do some research on that first.

Post by **Marc van Arc** » 25 Aug 2007, 10:27

apistomaster wrote:I'm glad you decided to buy the long nosed knife fish. There isn't much information on their care so maybe you will be able to fill in some blanks.

Hi Larry,
Thanks. I'll do my best. The first problem has already occurred: where is it?? (see above).

sidguppy · Post by **sidguppy** » 25 Aug 2007, 11:08

maybe it doesn't hide on the bottom.....if you still have the Giant Vallisneria or a dense layer of floating plants....wouldn't surprise me at all if the beastie turned up hiding just a few cms below the surface

several knifefishes are known to live and hide in the "floating islands" in the amazon; hiding in the dense roots of floating reeds and so on.

apistomaster · Post by **apistomaster** » 26 Aug 2007, 20:53

Marc,
Have you seen this leucomelanistic SA long nose knife fish? I have posted the link to Oliver Lucanus web site photo of this interesting fish
http://www.belowwater.com/Fish/237A8614 ... A0C30.html

Post by **Marc van Arc** » 26 Aug 2007, 21:44

Spooky.... Great name btw, anteater knife. Personally I prefer the naturally patterned/coloured specimen, but this is indeed very remarkable. Never seen it before, not even in books. Thanks for posting.

Post by **Marc van Arc** » 31 Aug 2007, 22:33

sidguppy wrote:maybe it doesn't hide on the bottom

Well, it should. The common name of Rhamphichthydae is sand knifefishes, which obviously refers to the habit you described earlier.
But.....still no sign of it. The species is strictly nocturnal, that could be a reason. And the sand is rather crowded, so I wonder if it's feeling at ease (if it's still feeling anything at all).

sidguppy · Post by **sidguppy** » 01 Sep 2007, 08:38

true, true

but we both know, sometimes fish don't read the books and refuse to behave as they should

maybe in a thick layer of sand (you got 2" I think) it can really bury itself?? at Tropifish the layer was thin....just a cm or so......

maybe check for just a head or a tiny moving piece of sand (gills); the shape of the fish allows it to go in "spiny eel style"

apistomaster · Post by **apistomaster** » 01 Sep 2007, 15:09

Marc said, "And the sand is rather crowded, so I wonder if it's feeling at ease (if it's still feeling anything at all)."

Marc,
Given their incredibly sophisticated electro-navigation and sensing faculties I would imagine it feels everything.
Pretty much everything from the fish's anal opening to the tip of it's tail is an electrical field generator and as fishes go, it has a large brain. It is one of the things that make them such an interesting group of fish to me.
It might be interesting to see if it would take advantage of a long clear acrylic tube like it's black ghost cousin. It would be nice to be able to see it.

Internet Aquatics · Post by **Internet Aquatics** » 09 Sep 2007, 20:02

you've bought a monster...and a very nice one at that.

As said, there is not a great deal of available information,however, the size factor is the obvious one...around the meter mark!

There benthic habitat can also give you a few clues...it would suggest a dimly lit tank for daylight and you could try using a red light when the main lights go off as this often - but not always - proves a successful way to view nocturnal species.

Foodwise, given time these guys should eat just about anything on the meaty side...bloodworm, shredded prawn, shredded lance fish...but it all depends on the competition from greedy tank mates.

GOOD LUCK

Kostas · Post by **Kostas** » 11 Sep 2007, 09:22

Its a real beauty!!!

You are lucky to find it and to get it...I had the chance to buy a similar knifefish some years ago and when i finally decided i am prepared to make a bigger tank for it and went to buy it,it was just sold

But it was the best knifefish i had seen,he was eating from my hand pulling its head a bit out of the water at the lfs eventhough it was wildcaught and just imported...

Good luck keeping yours Mark!!!

Post by **Marc van Arc** » 11 Sep 2007, 11:06

Thanks for all your comments and kind words, but I still haven't seen it since it was introduced to the tank, despite several hours sitting in the dark with very little light. I have to admit it worries me that I wasn't able to see a 25 cms long fish during those sittings. But I also haven't found a dead body, nor a hugely swollen Auchenipterid.....
I'll keep you posted.

Post by **Marc van Arc** » 11 Nov 2007, 20:15

Still haven't seen it. No way it's ever going to pop up again. Too bad....