Sevrum aggression

ryansmith83

Silver Tier VIP
MFK Member
May 2, 2008
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How long were they together before the aggression started? It’s rare that two severums work in a tank. They’re best as singles or in groups to spread out the aggression. When you keep two, a dominant fish will almost always torment a submissive fish. This also happens with two females, a non-paired male and female, etc.

Also, your second fish is not a rotkeil/red shoulder, which is why you don’t see any red on it. It’s a commercially bred efasciatus.
 

Scout1984

Feeder Fish
MFK Member
Jun 3, 2019
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Arizona
They were together about 3 months before aggression started at which time I removed the 2 females from the tank thinking it would help eliminate any aggression but did not help
 

neutrino

Potamotrygon
MFK Member
Jan 22, 2013
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Maybe id doesn't work just as often, but I've had two work in a tank a few times. I've also had two pairs work.

It can depend on species-- after that gender, individual fish, makeup of the tank, and other variables. The pairs in my two pair tanks (I had a couple of them going a few years ago) formed from a good sized group of rotkeils, not a mixed group of sevs-- maybe that was a factor.
 
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