2 Fish, 1 Terrorizing The Other

[Amunet]

We recently (2 weeks ago) got 2 golden panchax? killifish. Everything was ok for a short time, but I started to notice one of them would hang out at the top of the tank, while the other stayed near the bottom hiding in decor and such.
I thought it was just a bit stressed being in a new tank and everything so didn't think much of it. It was eating no problem.

Now however.. it seems like the one that stays at the top all the time is terrorizing the other one. The poor thing has it's tail fin pretty ripped up and just looks so stressed out.
We don't have any room in our other tanks to put it so I'm wondering what else we can do? I've tryed looking up info on if they're territorial (which we now are realizing is), but can't seem to really find too much info.. so we just need a solution on what we can do.

I think they're both males (both are pretty colorful and vibrant) if that makes any difference?

 

[BigC]

The upshot is that almost all killifish males (whatever species) cannot or will not abide the company of other males in close proximity. And even more so if you have a female in there with them. I would either seperate the harassed male or give him away to a fellow aquarist. More planting might work for a while but now the bullying has started its very hard to stop. The only true solution to a case like this is to swamp the tank with males (no females) that way squabbling is kept to a minium as every one is a target for each other. But aquarium constraints cannot allow for this. Sorry the only solution is to seperate or rehome the bullied fish.
Aplochelius lineatus (gold) is a colour morph of the wild form (which has some stripes on the latter part of the body and is a totally different colour from your gold form) They grow to around 4" (100mm) in the home aquarium (big fish) You will probably have bought them young at around 2" (50mm) and they are stunning to look at at that age and size. But beware there is a sting in the tail with lineatus. They are predatory by nature (not the fishes fault) They posess a very large cavernous mouth which can open quite wide and engulf smaller fish. I forget how many times I've warned fellow members on this forum about the dangers of keeping Aplo.lineatus with small tetras. (I am speaking from personal experience here) So if you have any small tetra or the likes in your tank I would think about rehoming both the fish.
They are a nice fish though, easy to breed, but their predatory nature makes them unsuitable for most aquariums that contain smaller fish species (e.g. neon tetra).
I hope this has answered your question.
Regards
BigC

 

[Amunet]

Everything in the tank is bigger than a neon tetra, but there are some smaller fish like the rasboras and the goby.

I was afraid we'd have to rehome one of them. Oh well.. hopefully the fish store we go to will take one or both.
Thanks a bunch for the info!

 

[Amunet]

Just a quick update

Alrighty.. so finally we've gotten another tank for the killifish.
I don't know why but fiance just did NOT want to take either of them to one of the LFS that I know would've taken them.. *shrugs*
It took us so long to get another tank for several reasons. 1 being that we're trying to save money to buy a house, and 2... our current home sucks. We have to pick and choose what we want to plug up b/c the wiring in this house is crap.

But blahblahblah.. after much debate. The beaten up killifish has a new 10gallon home he's sharing with 4 platies.
The tank is being medicated at the moment b/c it looks like the stress of getting picked on by the other one has caused him to get a bit of fuzz on a few parts of his body.
He's SO much smaller than the other killifish and his color is so much lighter and duller.
His tailfin is a bit frayed, but I'm hoping he'll make a full recovery now that he doesn't have anyone chasing him.
He seemed to take to his new home very quickly though. When I dropped in the med tablet.. he quickly went to inspect it, so I'm taking that as a good sign


I have a question about their behaviour when he was still in the tank. Sometimes the dominant male would I guess corner the weaker one at the bottom of the tank. But wouldn't do anything except for lay right next to him. No nipping, no physical contact. Just very close. I could clearly see that it stressed the weaker one out like crazy, b/c he'd be breathing heavily and just looked as stressed as any fish can.
I'm just curious to know what that was about? What was the dominant one doing?

Also.. while we were setting up the 10gal (it's right in front of the 28 where they both were)... the 28's lights were off for the night, but I could still see inside of it b/c of a lamp. Well anywho.. I noticed the weaker male swimming around as if nothing was wrong and the dominant one wasn't nipping or chasing him at all. They both saw eachother no problem and at one point, both came up to the surface to beg for food from me. Now what was going on there?
I'm not sure if that's normal behaviour for them since I usually don't bother the tank after lights out (startles the fish too much).

 

[BigC]

Are you absolutely sure you have two males. Aplo. linneatus (gold) are notoriously difficult to sex even to a trained eye. There are suttle differences though such as finnage. The best method is placing the fish in a bag and with a torch shine it at the underside of the abdomen, in the female, eggs will be present. This type of nudgeing usually relates to a spawning behaviour. The male will approach the female from the side and shimmy up alonge side the bodies will be aligned, a shaking motion will occur and the bodies of both fish will contort into a sort of an "S" shape, then there will be a sudden jerk and a fertilised egg will be deposited (usually on plant matter but also on substrate) Try making a couple of synthetic spawning mops (one attached to a cork and the other sunken) to determine if you have a sexed pair. Check these daily for signs of eggs. Use some floating plant such as Salvinia to dim the lighting which will also help. It could turn out that you have a sexed pair rather than 2 males.
Regards
BigC

 

[Amunet]

Well I think they're both males b/c the weaker one just wasn't having any part of the other male. It always hid when the lights were on and always ran from the other one when it was found.
When they were doing that odd behaviour I mentioned (laying next to eachother)... the weaker one would always escape when the other one got distracted. Maybe the dominant one was just confused or something? *shrugs*

Even if it turns out to be female I don't think I'll be putting her back. She, he, whatever is much happier in the new tank. Hasn't hid once and is swimming around w/ no fear which is great to see

 

[BigC]

OK
Happy Fishkeeping
Regards
BigC

 

[Amunet]

I didn't mean to come off like I wasn't taking your advice Big C if that's how you took it? Not sure.. it's so hard to get across your mood over the computer heh

I took into consideration all of the info you have given me (which is greatly appreciated) and just decided it's best if both killi's were seperated.
And also I don't think any of the other fish are in danger of being killifish food considering that they're really not THAT small (the other fish). I'll keep an eye on that though!

Anyways.. blahblah.. I just wanted to say thanks for all of the help

 

[BigC]

No problem Amunet,
Everythings cool.
I didn't mean it like that either, What I ment wa...s OK you've seemed to have sorted it and everything is fine so nothing more needs to be added.
People have the right to take or leave my advice, I wont be offended, but what I do know, comes from a personal standpoint/experiences and not from internet lookups.
I am still learning even though I've been in this game for over 35 years. I am not against taking advice from a novice, if it works. Then the knowledge base benefits everyone.
So dont worry I'm thick skinned.
Glad you sorted everything and a seperate aquarium/tank was the obvious solution.
Regards
BigC

 

[Amunet]

Small update...

Well.. I just got to see the predatory side to them a few mins ago.

The one in the 10gal is definitely feeling better.
I put in some adult platy and large platy fry in w/ it.
Everything was ok and since I'm having a bit of trouble w/ ammonia in my 5 gal (where the rest of the fry are)
I decided to try to take a few more fry out and put them in the 10gal.
Boy that was a big mistake!
It escaped my mind to try to get out only the larger fry, so I just took out the ones I could catch.
Plopped them into the 10gal, and went about my business.
Well I just looked into the tank a few mins ago, and sure enough.. the killifish was chasing down one of the newly added smaller fry. Poor thing would've been killi food if I hadn't stopped it.
I think it might've already eaten 2 of them.. blah..
Lesson learned lesson learned and rip lil platy fry.

 

[BigC]

There you go..
People sometimes just dont listen to me when I say sooner or later this species is going to hunt down smaller tank inhabitants.
Lovely & placid when juveniles but they do grow. And anything small enough to fit into their cavernous mouths is considered fair game.
Sorry to hear of your Platy loss but at least you got to see first hand what I seem to repeat over and over again in these threads.
Regards
BigC

 

[Amunet]

Yeah. The thing is that the fry really aren't that small (the 2nd ones I put in) they were just under an inch and this killifish isn't really big. I'm not sure if it could've swallowed the one it was chasing. *shrugs* I guess that didn't matter to it though lol.

Anywho... now I know and no more little fry will be eaten.

At least I know what to do if I ever have fry that I want to get rid of though lol *nodnod*