Serial Killer Fish- Skirt Etra Territory Aggression (long)

So, 2 of my original skirt tetras as alive. They have been through it all. 1 of them is a killer. he killed a skirt tetra by fin nipping weeks ago. I tried quarantining and hoping the tetra would heal, but day 4 he was dead. Yesterday, I found the body of a neon long dead missing a tail fin hidden by a leaf I have in the tank for tannins & a feeding area for the cory cat fish.

Oh, same fishes fin nipped & killed 2 cory cats just days after I got them. I have learned to not get sentimental over fish.

I have 6 plants in tank- added 2 after the other cory were killed for more hiding places the remaining 2 cories like to rotate on their path in front of tank. .

I almost removed those 2 tetras, but honestly, I really wanted a peaceful tank community for this tank. I had net out and ready to remove those 2 from tank & they all panicked so I rethought it.

I moved decor around to help with aggression and will flip it around again tomorrow and then just rotate the objects.

****Any other tips? ****

I've had them since late April and I'd really like to add more cory cats or something eventually. But at this point, it may end up last man standing.

I call him/them my Jack the Ripper fish. The 2 remaining cories seem wise to him ( 1 of 2 fish, not sure who is doing the nipping.)

* I added 4 glow fish tetras to tank over last 10 days, so they have a school now & are settling down some.

As I am typing this, I think those 2 ( because I'm not 100% sure the which one it is) has to be removed. I have a 5 gallon I can move them too. I may have to rehome them.

****has anyone had an aggressive Skirt Tetras chill out? I was hoping it was biological & fade after whatever mating/territory issues passed by.


current stocking:

38 gallon

6 live plants, a few fake plants, bridge, fake hiding tree & house to hide around ( objects I move to create new territory spaces)

6 skirt tetras
5 black neons
2 neons
2 cory cats

 

How many skirt tetras did you have when you started the tank? I would say you need a much bigger school to even out aggression but maybe something wrong with that one fish? I see you have six now.. is that helping?

Actually each of your fish need to be in schools of at least 6. I like 9+ for tetras and cories. So 6+ black skirt tetras , 6+ neons, 6+ cories etc. Otherwise with fewer fish they each get bullied more . If the two are really that terrible, I would have moved them into separate tank a while ago. I am assuming everyone is well fed and tank is properly cycled. (No ammonia, no nitrite) . I worry your remaining fish are too few and will be stressed from not being in proper schools

 

I started tank with 8 neons and 8 black neons, plus the 2 skirts.
Aggression started about 4 weeks ago? so 6 weeks after I got them.

I plan on getting more to fill back up the schools later this week.

 

Started with just two skirt tetras? Pretty sure most people on this board will say that's the issue. Need at least 6 for a school otherwise they will pick on other fish.

 

I originally had 6 white Skirt Tetras in a 10 gallon - but 1 was actually a silver dollar the pet shop guy netted & sold by 'accident.'
After a few weeks, he got too big & the other tetras ignored him. (He is now in a 36 gallon tank with 3 other silver dollars and they are doing well. )

2 others died due to a water change issue. Then 1 died from fin nip attack which happened almost immediately after the water change problem. That left me those 2 from original purchase of 6 white skirt tetras when I moved the fish to the 38 gallon tank.

so yes, I understand they need a school, but because of the attacks ( 1 tetra, 2 cory & now 1 neon) I was hesitant. I slowly added new fish 2 at a time to see how stable it'd be. No attacks on the glow fish tetras as yet. I was just stunned by finding the dead neon missing it's tail since it happened after I had 6 skirt tetras in the tank, hence my post.

 

Did you see them actually kill other fish?

 

No, but they were the only 2 left at the time breed in tank that fin nipped or displayed territory aggression ( chasing etc).

The new glo fish tetras have not shown any signs so far. if it happens again, they go into back into 10 gallon tank.

 

Started with just two skirt tetras? Pretty sure most people on this board will say that's the issue. Need at least 6 for a school otherwise they will pick on other fish.

I'm having the same problem. I've lost 3 otocinclus, 1 neon tetras and one platy. I have moved the six, being three white and three black skirts to their own 29 gallon tank. Now, I have one male white that will not come out of hiding, but I'm not sure which one he's afraid of. Don't know what I'm going to do, but it's definitely one, if not both of the two white females that are the aggressors. I had them for 8 mths in a 60 gln community, but kept losing fish, then realized fins were missing on the last few I found dead. I'm at a loss.

 

Cindy, I am sorry to hear this.

I restocked my tank to be: 6 neons, 3 black neons, 2 more cories and then later 3 more cories. I'll never buy another neon tetra , they are far too fragile. only 1 of the new neons lived and 2 of the new black neons.

Currently 6 skirts ( glow fish & 2 original white skirts) 5 cories, 3 neons, 6 black neons. No new deaths in a few weeks from fin nipping. I added a large plant that outgrew a 10 gallon. It's pretty massive.

My co-worker wanted the fish, but he's living with his Mother In law & doesn't have room. It would have been a good fit as he has had fish before. but oh well.


If I see any more such aggression, no new fish to that tank until they are gone. I'm not going to feed the monster. The skirt tetras really do not school. What is cute is the black neons will get confused and start to follow the cories as they swim around.

 

Cindy, I am sorry to hear this.

I restocked my tank to be: 6 neons, 3 black neons, 2 more cories and then later 3 more cories. I'll never buy another neon tetra , they are far too fragile. only 1 of the new neons lived and 2 of the new black neons.

Currently 6 skirts ( glow fish & 2 original white skirts) 5 cories, 3 neons, 6 black neons. No new deaths in a few weeks from fin nipping. I added a large plant that outgrew a 10 gallon. It's pretty massive.

My co-worker wanted the fish, but he's living with his Mother In law & doesn't have room. It would have been a good fit as he has had fish before. but oh well.


If I see any more such aggression, no new fish to that tank until they are gone. I'm not going to feed the monster. The skirt tetras really do not school. What is cute is the black neons will get confused and start to follow the cories as they swim around.

oh wow.... es, neon teyras ate awrsome, very peaceful. I habe them. with platys, corydoras's and otocynclus in my 60 gln now, and the monstets in a 29. I went to the PS and bought 4 more white skirt females and 1white male yesyetday because my 1 white male was being harassed by the 2 black skirts. They told me it would help having more females. I did it and so far so good. My white male has come out of hiding. I just really don't like the aggressive behavior. Everyone of them are constantly chasing someone. and you're right, they don't school, but now they're all together and can't harm any other fish. I'm done with them once these live out their lives. By the way, my Cory's had eggs (I saved them) and now I have at least 50, theure all almost 2 months old.... lol
I think I've lost my mind!

 

oh wow, 50!!! That's impressive. So glad to hear your tank is doing better. I'm thinking about moving them to a 10 gallon & isolate them if there's another issue. The problem I have is room. Because I have so many Bettas, I'm at max capacity until my dining room is redone as a 'fish room' hopefully next spring.

 

So, 2 of my original skirt tetras as alive. They have been through it all. 1 of them is a killer. he killed a skirt tetra by fin nipping weeks ago. I tried quarantining and hoping the tetra would heal, but day 4 he was dead. Yesterday, I found the body of a neon long dead missing a tail fin hidden by a leaf I have in the tank for tannins & a feeding area for the cory cat fish.

Oh, same fishes fin nipped & killed 2 cory cats just days after I got them. I have learned to not get sentimental over fish.

I have 6 plants in tank- added 2 after the other cory were killed for more hiding places the remaining 2 cories like to rotate on their path in front of tank. .

I almost removed those 2 tetras, but honestly, I really wanted a peaceful tank community for this tank. I had net out and ready to remove those 2 from tank & they all panicked so I rethought it.

I moved decor around to help with aggression and will flip it around again tomorrow and then just rotate the objects.

****Any other tips? ****

I've had them since late April and I'd really like to add more cory cats or something eventually. But at this point, it may end up last man standing.

I call him/them my Jack the Ripper fish. The 2 remaining cories seem wise to him ( 1 of 2 fish, not sure who is doing the nipping.)

* I added 4 glow fish tetras to tank over last 10 days, so they have a school now & are settling down some.

As I am typing this, I think those 2 ( because I'm not 100% sure the which one it is) has to be removed. I have a 5 gallon I can move them too. I may have to rehome them.

****has anyone had an aggressive Skirt Tetras chill out? I was hoping it was biological & fade after whatever mating/territory issues passed by.


current stocking:

38 gallon

6 live plants, a few fake plants, bridge, fake hiding tree & house to hide around ( objects I move to create new territory spaces)

6 skirt tetras
5 black neons
2 neons
2 cory cats

wow.... that's cool. I want more schooling fish but my platys keep reproducing. I think I gave them too many hiding places. If I were you, I'd put your skirts in a separate tank if you can find room. they are mean, but my tank with 12 of them are now doing great, and my other fish are a lot happier, especially my Oto's.
I did go to the PS just today after church and they will give me credit for them. They said they cannot keep enough of them because they sell out so fast, so they're going to give me a dollar a piece credit, that's awesome! I think I'm going to just start breeding Corydoras since I had so much luck, LOL. Anyhow, if you lived near Pensacola I'd give you some. They are too cute !

 

Cindy, I am sorry to hear this.

I restocked my tank to be: 6 neons, 3 black neons, 2 more cories and then later 3 more cories. I'll never buy another neon tetra , they are far too fragile. only 1 of the new neons lived and 2 of the new black neons.

Currently 6 skirts ( glow fish & 2 original white skirts) 5 cories, 3 neons, 6 black neons. No new deaths in a few weeks from fin nipping. I added a large plant that outgrew a 10 gallon. It's pretty massive.

My co-worker wanted the fish, but he's living with his Mother In law & doesn't have room. It would have been a good fit as he has had fish before. but oh well.


If I see any more such aggression, no new fish to that tank until they are gone. I'm not going to feed the monster. The skirt tetras really do not school. What is cute is the black neons will get confused and start to follow the cories as they swim around.

lol, yes, I've seen neon's get confused. In my large tank when the baby platys finally come out, they also school with the neon s. I love a peaceful tank. It's nice talking to you.