Endler's Fin Nipping

strideth

AC Members
Mar 5, 2007
7
0
0
Santa Clara, CA
I hadn't heard this before about Endler's, but apparently mine are fin nippers extraordinair. I have 10 Endler's juvies, ranging from 1/4" to 1/2", in with two (er, one) dwarf Platy. The Platys were both about an inch, 4 to eight times the body mass of the Endler's, but any time one showed it's face, any (including the really little guys) Endler in sight immediately went for the Platy's tail. To the point where I am fairly certain they killed one of the Platys. The poor platys have to run away anytime an Endler saw it. Is this normal, or are the juvies just overly aggressive?
 
I would assume so, but as I said, all 10 are juvis, so its a bit hard to tell at this point.
 
Male Endlers are constantly horny and are likely to try to mate with any larger flish they come across if no females are available. But this sounds like downright aggression rather that mating harrassment.
Are the Endlers showing their colors? And you're sure they are actually Endlers?
 
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Well, they came from John N., so I'm fairly certain they are Endler's. No color on any of them, but at 1/4", it may be a while on some of them. Also no possibility of sexing them, but with 10 the odds of having both sexes is fairly decent. It looks like flat out aggression, once an Endler sees a Platy, it will chase the poor thing all around the tank until the Platy manages to hide behind a rock or leaf. Just seems strange for what is supposedly an extremely placid type of fish.
 
I had an ultra aggressive Endler once. But he only picked on other Endlers, not fish ten times his size. Wierd.
 
OK, apparent resolution on this. Someone on the EndlersRUS forum suggested that the platties had a case of fin rot, and that the endlers would pick off the dead finnage.

After losing the last of the three fish, I took them back to Petsmart (shudder). I rechecked the dwarf platty tank, and they still had a couple of them left, and their rear fins looked ragged and picked on. Looks quite a bit like the entire batch had fin rot, which would explain the Endler's behavior.

Petsmart had just gotten in a new batch of dwarf platties that day, and since the exchange was free, I thought I would try one more time. The fins on the newer platties looked quite normal. I've had the new pair for a couple of days now, they are much more active than the previous ones, and the Endler's aren't paying any attention to them at all. So it appears to be just a bad batch of fish at Petsmart (big surprise there).

Thanks everyone for their help.
 
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