[xylella]

i just had to stop one of my bettas from killing one of my last remaining cardinal tetras. it honestly came out of no where, i’ve had both cardinal tetras and neon tetras in my sorority tank for over 2 months and have never had an issue. i fed my girls some mosquito larvae about an hour ago as a treat, and then when i looked at the tank, Seraphine had one of the tetras in her mouth and was shaking it like a dog. i managed to get the tetra away from her, but it died anyways. i guess my main question is, why would a well-fed female go after a peaceful tank mate?? they eat every night and get a nice variety of shrimp, daphnia, bloodworms, and live food as treats. also, would it be bad to put the dead tetra back in the tank? i feel like it’s a waste to throw him away, but i’m worried that if i let the girls eat him that they’ll see my last remaining cardinal as food, and possibly turn on the neons as well?? after i pulled the dead tetra out, the other girls lost interest, but Seraphine spun around and tried to go after the last cardinal. i just don’t know what the best option is here.

RIP Red Minion, you were a real one

edit: there is tons of plant cover (over 50% of the tank) so typically if any of the betas get a little too snippy the community fish will all just hang out in the plants. i don’t think anyone in the tank was expecting Seraphine to turn like that

 

[BettaloverSara]

How many betta are in the tank? How many tetras? It isn't about being hungry but access to food is part of dominance so it can be the trigger for aggression. The older they get the more aggressive and dominant they will become. Could be because she is trying to assert herself as top dog, or maybe she is being picked on herself. Tetras can also be nippy and dumb so I don't know that I would put them in the peaceful category. I have found over the years that it depends on the personalities of both fish if they can live together or not.

 

[xylella]

5 bettas, 5 tetras. now 2 neon tetras, because both cardinals were killed as well as a neon. i pulled her from my tank, and no other little fish have died. i also noticed earlier this week that she was picking on my littlest female (PetCo betta that has just had a little bit of a hard time growing). after i removed Seraphine, Rakan (the little one) has been more at the front of the tank instead of the top corner. i’m hoping that a couple of days in a tank by herself will settle Seraphine down, and the other girls will get into a good rhythm again. Seraphine is the second lowest female (second to Rakan) so i’m wondering if that was creating a problem. Davis (my top and biggest female) as well as Xayah (my second top female) stopped reprimanding her for bad behavior after Rakan and Lillia were introduced.

i’m going to try her in the community tank again either tonight or tomorrow night after i feed them, but if Seraphine continues to harass the tetras, catfish, and other bettas, she’s going to have to be a solitary fish unfortunately. i’m just disappointed because we had a really really good group going, so i’m not sure what made her lash out this week in particular.

 

[RussellTheShihTzu]

She is probably stressed so I imagine Seraphine would love being an only fish. They are a solo species; not shoaling/schooling. Quick fish like Tetra don't need to nip or chase to cause some Betta to stress. And sometimes this stress manifests itself into aggression and often illness.

If you tank is now doing more peaceful I would not put Seraphine back. You'll just start the stress cycle all over again.