Black Ghost Knife harassing my Scat fish

[Boogery]

I have a 125 Gallon setup. 2 large pieces of wood (many branches), 2 large plastic plants with wide leaves, a few large hides and some live rock with holes. Bare bottom.

Here are my fish along with approximate size:
1 BGK (about 11-12"), 2 Scat (7-8 inches), 5 clown loach (3-4 inches), 1 discus (adult), 2 rainbow fish (4 inches), 1 tiger datnoid (about 6 inches), 3 plecos - green phantom, bristlenose and snowball (all about 3 inches).

The BGK used to hide under one of the large pieces of wood until a few weeks ago. For some reason he doesn't go under there anymore and there's nothing under there that could really harm him. All of my equipment is inline so the only thing in the water is the intake and spray bar return. He has been sharing the space with the snowball pleco but they never fought. The wood is on the right side of the tank and the datnoid hangs out in the corner on the right side too. Datnoid and BGK fish have no problem being around each other and also don't fight.

My BGK is not one to sleep all day and is usually out and about at least part of the time in the day and buzzes around the tank all night. About a month or so ago, when the scat would come by he would spring out from under the wood and punch at them. He can't really bite them even though he's about 12 inches but the scat don't like it as they are really peaceful fish.

Now since my BGK has moved he harasses the scat during the day and non-stop at night. I put in 2 large hides for him to use but he hasn't used them yet and tends to want to just lay in the plastic plant leaves all day. He doesn't harass any of my other fish, only the scat. I'm not sure what else I can try to stop him from doing it but if they don't stop I am going to have to rehome my scat which I really don't want to do since I raised them from tiny babies (along with all of the fish in my tank). These fish pretty much have grown up together in this tank minus the datnoid that I just got about 6 months ago.

Anyone have advice on what I can try? I ordered yet another large hide to add in to give my BGK more choices but he's never been one to fully hide anyway. Tried many tubes - clear, PVC, etc. but he seems to want to just be out in the open now all the time and chase the scat. I've tried rearranging things, adding things, taking things out but his behavior doesn't change. I can post a pic of my tank if that helps. Thanks in advance!

 

[tlindsey]

I have a 125 Gallon setup. 2 large pieces of wood (many branches), 2 large plastic plants with wide leaves, a few large hides and some live rock with holes. Bare bottom.

Here are my fish along with approximate size:
1 BGK (about 11-12"), 2 Scat (7-8 inches), 5 clown loach (3-4 inches), 1 discus (adult), 2 rainbow fish (4 inches), 1 tiger datnoid (about 6 inches), 3 plecos - green phantom, bristlenose and snowball (all about 3 inches).

The BGK used to hide under one of the large pieces of wood until a few weeks ago. For some reason he doesn't go under there anymore and there's nothing under there that could really harm him. All of my equipment is inline so the only thing in the water is the intake and spray bar return. He has been sharing the space with the snowball pleco but they never fought. The wood is on the right side of the tank and the datnoid hangs out in the corner on the right side too. Datnoid and BGK fish have no problem being around each other and also don't fight.

My BGK is not one to sleep all day and is usually out and about at least part of the time in the day and buzzes around the tank all night. About a month or so ago, when the scat would come by he would spring out from under the wood and punch at them. He can't really bite them even though he's about 12 inches but the scat don't like it as they are really peaceful fish.

Now since my BGK has moved he harasses the scat during the day and non-stop at night. I put in 2 large hides for him to use but he hasn't used them yet and tends to want to just lay in the plastic plant leaves all day. He doesn't harass any of my other fish, only the scat. I'm not sure what else I can try to stop him from doing it but if they don't stop I am going to have to rehome my scat which I really don't want to do since I raised them from tiny babies (along with all of the fish in my tank). These fish pretty much have grown up together in this tank minus the datnoid that I just got about 6 months ago.

Anyone have advice on what I can try? I ordered yet another large hide to add in to give my BGK more choices but he's never been one to fully hide anyway. Tried many tubes - clear, PVC, etc. but he seems to want to just be out in the open now all the time and chase the scat. I've tried rearranging things, adding things, taking things out but his behavior doesn't change. I can post a pic of my tank if that helps. Thanks in advance!

Welcome aboard

Although some fish will grow together they may change for the better or worse as they mature. The only thing you can really do is remove one of them.

 

[amazontank]

Definitely post some photos of that tank that would be awesome! That large black ghost knife is a real prize!
I never seen a bgk harass a particular fish like that so maybe it's a phase you can let it play out a couple more months or remove that scat imo.

 

[Boogery]

Here are a few pics of my 125 gallon. I used to have more discuss but they kept dying on me and I still have the one male left. I have this tank because of my BGK fish that I call Leroy and got him when he was about 2 inches long and just tiny. All of these fish went in at the same time except for the datnoid. I have 3 plecos in there along with 5 clown loach who are of course hiding because the lights are on. I just rearranged the tank not to long ago to remove a giant piece of live rock that the clown loach could not fit into anymore so it was taking up space. I added a hide in the back middle and I have 2 more giant hides coming in Sunday and hoping the BGK takes to one of them. The datnoid claimed the other hide that's in there now when he's not laying down in a corner. My BGK used to hide in the pipe decoration until he got kicked out by my green phantom, then hung out for at least a year under the wood on the right side of the tank. I am thinking my other 2 plecos kicked him out from there but clearly something happened a few weeks ago and he doesn't go under there anymore. He seems pretty happy laying in those big leaf plants I put in there now and I added those to try to provide some canopy for him. I'm going to add those other hides and see if things get better. I used to also have a pretty large syndontis (Bruce) and unfortunately had to rehome him because he kept attacking my BGK fish. I would give up all my fish for my BGK and he is just really fun to watch. Just does crazy stuff. I find him sleeping sometimes just dead still and every time it still scares me.

 

[amazontank]

That bgk is awesome how old it's very cool you raised from a baby?
Imo the bgk needs much better areas to hide. The pvc is way to small now that she is getting larger, maybe even potential to scratch the delicate skin.
Even a slate or wood against the glass can work well.
Also I wouldn't trust the datnoid it could think the tail was a worm and bite the ghost.
How is the tail is it in perfect condition? On the
Scats they could just look intimidating to the ghost and with nowhere for the bgk to hide and feel secure could make ghost a little stressed and latch out.
That's one of my setups I have a 16"+ male and 14"+ female doing well in there probably 10 years! They love that hollow log on the left and the hollow logs on right are nice. On those I added some pond rubber because the inside edges were sharp.
The Large clear Lees ghost tubes worked for many years for me now there to big.

 

[amazontank]

Here is a pic from many years ago piece of wood leaned against the acrylic already growing to big for that but it was cool to see him all day long hanging out!

 

[Boogery]

Wow, that is pretty cool, especially since you have 2 large ones in the same tank! Mine is about 2 1/2 now (not really sure if it's a he or she). My hide situation is not ideal right now but I'm hoping to fix it this weekend when I get some bigger hollow logs in. They are more of the store bought kind but I'm looking for some real wood solution soon. I have tried PVC, those clear acrylic tubes and laying things against the glass and he has not gone in them. It's like he almost prefers to be out all the time and it was really weird that he chose to hang out under that piece of wood next to my intake for more than a year because it was pretty much out in the open.

I'll keep an eye on the datnoid. I've actually read in these forums they are OK as tank mates but the main concern would be the BGK eating the eyes of the datnoid. All of my fish are on pellets but I also feed shrimp once a week and frozen a few times a week to mix things up. I am considering isolating the datnoid in my hospital tank to get him on the pellet program (gonna try massivore delight and carnivore sinking pellets). If he doesn't get with the program he may have to be rehomed anyway.

 

[amazontank]

That all sounds great!
It's just my opinion and experience on the bgk.
Ofcourse I seen them with Cichlids, Oscar's, giant Bichirs and everything else some may have worked and some didn't work at all for sure.
I seen a Bichir practically break a bgk tail clean off and they were friends for a year. Plus ghost at night drive everything crazy since there all over the place.
The rounder nose on yours shows female, that closeup of mine is a male with longer horse like nose.

 

[Toby_H]

I don't have any answers...

But I love seeing examples of Black Ghost Knives being the bad asses I know they can be.

I used to have a 12"+ BGK that hung with some pretty tough Cichlids. He lived with a full sized adult Pair of Dempseys for a while and would eat every fry they produced. The Dempseys did everything they could to protect the fry but the BGK was just too darn fast and out maneuvered them as he plucked fry. It was amazing to watch.

As you pointed out, something changed a few weeks ago. If you can't single it out and counteract the change, maybe consider making new changes and see what happens. Large scale re-scape maybe?

 

[Toby_H]

I was looking at some old pics tonight and came across this one.

That's a really crappy pic of a ~12" BGK, a 5-6" female Trimac and a breeding pair of Convicts. For reference that structure is 12" x 12" x 12"

The Knife never got picked on and ate all sorts of fry (though never Trimac fry).