African Brown Knife Fish

Hendre

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I got mine for 7USD each roughly @3.5" and 4.5"

That's quite a lot!
What size tank did you keep them in?
 

Hendre

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Oh alright. I keep a male duo in my 70

Check the sticky I made under knifefish :)
 

Dragon2

Jack Dempsey
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Does anyone know HOW exactly they make that noise? First time I introduced a 2nd african brown knife (rescue fish, I said I try with my own knife, luckily it worked out), the noise was off the charts :p I could hear it while watching TV a few meters away, took me a while to figure out it was them :rolleyes:

They have settled down a long time ago but every now and again they start gulping air (always large one first then smaller one) then shortly after making that noise again.

Of course when you try to get it on video, they mostly stay quiet :rolleyes:
(Older) video:
 
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Hendre

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Is it that popping noise?

From what I know it's a courtship sound, with my group of 4 I've never ever heard it. Do you mind if I post this on my sticky thread?
 
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andyroo

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Sexual dimorphism? FishBase etc say "No", but still curious.

Ours has a little point projecting from (around the area of the) anus that would be a sexual apparatus in other fish/genus/species. I see no references to such a projection online. He/she came from the shop small & well fed and with this projection- I did notice others in the shop/shipment to have had similar. These days he/she's fat, (like properly fat- living in scud/snail/guppy grow-out tank) and growing like mad, and retains this structure/issue.

Vestigial ventral fin that's rarely expressed? Injury? Parasite?

I'l try to get a picture, but not holding breath.
 

Hendre

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Sexual dimorphism is based on the gonad which is under their organs. If it's perpendicular to the body it's a female and if angled backwards it's a male. If going by this I have 4 males.
 
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andyroo

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Sexual dimorphism is based on the gonad which is under their organs. If it's perpendicular to the body it's a female and if angled backwards it's a male. If going by this I have 4 males.
Brilliant, thanks.
a) as I remember it's sticking straight downwards (a she?), and
b) next time I'm in the city, I'll check the shop to see if they've still got in stock (had lots, selling slowly). Specifically, I'll check the alternate apparatus. Can't win if we don't try :)
 

Hendre

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Sticking down should be a she... One of mine also had this appear, believe it's an ovipositor (the grey thing)
IMG_20180912_183511.jpg
 

andyroo

Peacock Bass
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Thanks again, Hendre.
Finally got a good look- the "projection" has a distinct backwards angle, and is a little longer than in your picture = male.

Q#2: a few months on and the belly is still very fat, but growth has greatly slowed/stopped. In fairness the species has a reputation for slow-growth and the water quality's likely very "alive" but also likely not pristine in the grow-out tank, and there is quite a bit of grub to be had for anybody willing to grub for it. I am interested in internal parasites considering the whole bunch in the shop had this fatness and he's not lost it. If so, I'd also be interested in how I might set about eliminating such parasites.
 
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