# MM Platy - aggressive?



## jimsz (Oct 11, 2011)

MM Platy - aggressive? 

In our newer 40gal tank over the last couple weeks we introduced a MM Platy and a number of smaller fish.

A couple have died but looked beat up to me. Tonight I was watching a glofish danio and it was fine. A couple hours later he was clearly injured and looked beat up. While watching the tank the MM Platy cam by and nipped him.

A while later someone else noticed the MM Platty nipping some other fish.

Are they normally aggressive fish? There are two other platies in the tank and they are quite passive.

I think I will be returning the MM PLaty to the store tomorrow, as well as exchanging the now dead glofish.

Is it worth getting another Platy or should I just get something a bit more passive?


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## holly12 (Apr 21, 2011)

Is it a male platy? Are the other 2 platies male or female? Maybe it wants to mate and if the other 2 are males, he's frustrated because he can't? If the other's are females... I'm not sure. If it really bothers you, you can trade him in.

Do you have the glofish in a school? They are a schooling fish, and maybe the platy wouldn't bother with him if he were in a group?


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## jimsz (Oct 11, 2011)

Yes the glofish is in a school. A neon tetra also looks like he has been nipped and he is an a school too.


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## holly12 (Apr 21, 2011)

Hmmm... what about the other 2 platies? Are they males? If so, then maybe he's frustrated because he wants to breed. If they are females, then he may just be an aggressive fish.


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## jrman83 (Jul 9, 2010)

I have seen one or two Platies be a tad aggresive and pick at other fish butI can't say that I've ever seen them cause any damage to another fish. Males I don't think get sexual frustration, but they will perform the same similar actions that they would have, had the fish been a female Platy. Can you give a little info on your tank, like the size and what else you have in there? How long has it been set up?


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## jimsz (Oct 11, 2011)

jrman83 said:


> Can you give a little info on your tank, like the size and what else you have in there? How long has it been set up?


It's 40 gallons, this tank was setup a week and a half ago as a transfer from another tank.

All water quality tests are as they should be (Ammonia 0, Nitrates 0, Nitrites 0, pH is a little high due to our water here).

The other fish are 2 Danio's, 3 glofish danios, 8 neon tetras, 2 red wag platies and the MM platy.

I have no clue which of the platys is male or female.


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## jrman83 (Jul 9, 2010)

Hmmm....my gut feeling is that unless you have actually seen the Platy show aggresion with visual marks from the aggression, I would lean toward one of your other fish. Danios have more tendancy to be tail nippers and from what I've read here and there, get a little crazy without more being in their group. Livebearers appear aggressive to some, but in the hundreds I have had/have I have never seen one do any sort of damage.


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## jimsz (Oct 11, 2011)

jrman83 said:


> Hmmm....my gut feeling is that unless you have actually seen the Platy show aggresion with visual marks from the aggression, I would lean toward one of your other fish. Danios have more tendancy to be tail nippers. Livebearers appear aggressive to some, but in the hundreds I have had/have I have never seen one do any sort of damage.


I saw the platy nip the injured fish after he was injured and another person saw the same thing as he nipped a neon tetra. I thought it was odd considering everything I was told about platies.


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## jrman83 (Jul 9, 2010)

No, no...not really saying they don't do it....I'm just saying that I have never seen any damage caused by it. My male Guppies go at it all day long with their long fancy tails, but none ever get damaged. Take the Platy back.


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## HFGGHG (Aug 28, 2011)

A male platy will have what's called a "gonopodium", a rodlike organ developed from the anal fin. 
I currently have 6 platies and finally spotted this on my red platy.
I noticed that none of the other platies had it. Red, as I call him,
is definitely more aggressive. The other platies are quite passive.
By aggressive, I mean chasing away the Mickey Mouse and painted platies (both female). Red does not do this to the 2 rainbow blue platies (both female also.) He schools with the blues. 
So...I bought another male platy, thinking that Red needed another male.
He chases away the other male too!
I have not seen him nip any of the platies or other fish in the tank which include danios, neon & serpae tetras.


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