Black Ghost Knife Help!


New Member
I have had my Black Ghost Knife for a week now, he’s been happy until yesterday. I noticed he has some mark on his body which I’m certain wasn’t there before. Then I was watching him last night thrashing around near the heater where my Bristlenose was trying to also claI'm a spot near, on the glass. (BGK has plenty of hiding spots). The Bristlenose eventually moved elsewhere.

Then this morning I saw him perched over the suction cap where the heater is, just resting on it, not moving. Thankfully he moved and wasn’t dead. I noticed his fin at the bottom is now frayed/torn in one part. I’m super worried because I hope he’ll be ok (he’s my favourite) and I’m concerned my Bristlenose has attacked him. What should I do?? Please help with advice

In my tank I have
1 Ghost Knife
1 Bristlenose
2 Angelfish
3 Ram Chiclid (blue ram, electric blue ram, yellow balloon ram)
4 Corydoras



Fishlore VIP
Highly unlikely that the BN attacked him, they are very passive and don't really have much to do damage with either. I think he must have hurt himself banging on the heater or other decorations. What size tank is he in?


Active Member
Hi! How long has your tank been set up and what size is it. I’d say it’s quite possible it’s your Angelfish acting up and went after him, especially if they were there first. How big are the angels? Nikm is also right to check your setup for anything he could be getting caught on, but Angels are both territorial and aggressive especially as adults and could be nipping at him to show him whose boss if he is the new guy. I’m not sure if I would call them compatible unless in a VERY large tank as the BGK gives off a little electrical current and the Angels may perpetually be on the warpath because of it. They can be pretty touchy especially if mature size.

If there isn’t already a good place for BGK to hide in there I’d add one for him he is looking pretty stressed.


Well Known
I would guess it’s very likely that the BN and the Knife are not getting on. A plec has weapons (fin-spines and rough armour-plating) that can do a lot of damage to a “scaleless” fish (BGKs are not scaleless but their scales are so small they may as well be). If they’re jostling for the best hide the Knife will quickly get scratched and damaged.

I’ve kept a few BGKs and I’ve learned never to keep them with plecs. They usually don’t get on at all.

The favoured hide of a BGK is a pipe (hollowed out branch). Give it a thin piece of pipe that the BN can’t get into(?) and it’ll be safer... but the Knife probably won’t come out much while the BN is around.


Fishlore VIP
Fish will quickly get stressed if they are fighting over a spot all night.

My Bristlenoses are territorial for sure and bang into their competitors with their hard spiny parts.

I also noticed there is no heater guard to prevent fish hiding there from burning.

All my heaters have guards.

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