Calling all Black Ghost Knife experts

[isu_guy]

My small BGK killed and ate part of one platy during a time of severely decreased feeding due to some ammonia levels.

Thats all straightened out now.

I noticed today that my other platy looks like his fins might have been nibbled on. He's also losing some of his color.

Is a platy too small to keep with a small BGK? Am I not feeding the BGK enough?
any other ideas?

thank you

 

[Oddball]

Not being funny but did u see the knife kill the fish? Ammonia can knobble any fish (and especially bgk's as they are very sensitive to this sorta thing), Also ammonia, nitrite and nitrate poisoning can cause fins on a fish to erode rapidly. How many fish are in there? and can you rehome the more delicate ones? Also u ask is the platty too small, i can't honestly answer this as you haven't told us how big the bgk is. Not wanting to sound odd here but a tad ore information like fish size and water measures as well as tank size would help us to answer your query better....
But i hope this helps for now

 

[isu_guy]

the bgk is about 5-6 inches long.
The first platy was definitely killed by the bgk, its was missing an eye and its stomach was ripped open.

the other could have suffered due to ammonia, there was a spike. My levels now:
Ammonia 0-.5ppm
Nitrite:0
Nitrate-don't test, but I do water changes very frequently, so I would doubt it could be very high.

I also doubt that the ammonia is a problem, because I did a water change today and the new water always reads some amounts of ammonia because of the chloramine being broken down by the water treatment.

 

[Oddball]

Isu, hate to tell ya this but unless you saw the knife attack the fish then u can't be sure. I've noticed whenever i have lost a fish, many fish try to eat it, even vegetarian fish, often removing the eyes and stomach first as its the easiest bits to eat first

 

[a1wonder]

From what I've read it is not unreasonable to concider the black knife taking a bite out of your smaller fish out of cursiousity how larger where the two pattys that have either died or are currently subject to the mysterious evening attacks?

 

[AquaSeaFoam]

How big is your tank? I know someone with a BGK thats already 16" at least. They need very big tanks... and will eventually eat all your platies most likely

 

[isu_guy]

He's currently in a 20gallon but will be transfered to a 55 and after that if I can get my hands on a 75 he'll go there.

 

[isu_guy]

Also- question about diet.

I'm trying to vary his diet a little with mixed results.
He's pretty much associated the lights clicking off with feeding time. I have my lights on a timer and as soon as they click off I can see him shooting to the surface and swimming back and forth scanning for food.
He loves bloodworms (to no surprise). He will take freeze dried tubifex worms but does it almost reluctantly, he swims around and around until he is sure there aren't any bloodworms to be had. I'd read that some people would feed cooked shrimp (human food), tried and he didn't take it. I've put in some sinking brine shrimp pellets - cant tell if any are eaten or not, and ifso by whom, but not a crowd favorite.
And oddly enough I saw him today nibbling on the pleco's zuccinni (which explains why I was so surprised at how much zuccinni my pleco went through the night before. I thought, boy thats amazing how much he ate, but now I figure that part of that consumption was done by the BGK). Anyway, any suggestions of stuff your BGK loves?

 

[BlueIce]

BGK do not attack and kill fish the same way other fish may.They will swallow a fish WHOLE however.So anything that can fit in the mouth is fair game.
A BGK will pick at a DEAD fish as well.I highly doubt that a BGK pecked the eye from a fish or tore a fin...it just isn't the way they act.


What are you feeding and how often?

 

[Final Dynazty]

Yeah you have to consider BGK are blind so they use sonar to find food anything that is small and moves it will kill and eat. My BGK is about 8 in. and dosn't bother any of fish ecept the sharks, B ut my other fish are smart to get out of its way though.