What's up with my Sailfin mollies?

[Cory]

We just picked up our two gold sailfin mollies from a friend who was fish
sitting for us while our new tank cycled. We had only had them for a short
while before our ammonia spiked and started killing some of our other fish.
That's when we decided to let a friend fish sit the two mollies because we
really liked them and didn't want to lose them. Anyway, our tank finally
completed it cycle a few days ago so we picked up the mollies today. One of
the mollies is constantly chasing the other, nipping (or at least it looks
like nipping) at it underneath. They are both males and I don't recall them
doing that before we took them to our friend house. I can't really tell if
it's bothering the one being chased, but it looks annoying to me. We are
new to aquariums so correct me if I'm wrong, but I always thought a fish
would raise its fins when it was being aggravated. Is that true? Neither
of the mollies have their fins raised. Anybody have any idea on what the
heck they are doing?

Thanks,
Cory

[Ozdude]

"Cory" > wrote in message
news:GCtYd.62307$SF.43795@lakeread08...
> We just picked up our two gold sailfin mollies from a friend who was fish
> sitting for us while our new tank cycled. We had only had them for a
> short while before our ammonia spiked and started killing some of our
> other fish. That's when we decided to let a friend fish sit the two
> mollies because we really liked them and didn't want to lose them. Anyway,
> our tank finally completed it cycle a few days ago so we picked up the
> mollies today. One of the mollies is constantly chasing the other,
> nipping (or at least it looks like nipping) at it underneath. They are
> both males and I don't recall them doing that before we took them to our
> friend house. I can't really tell if it's bothering the one being chased,
> but it looks annoying to me. We are new to aquariums so correct me if I'm
> wrong, but I always thought a fish would raise its fins when it was being
> aggravated. Is that true? Neither of the mollies have their fins raised.
> Anybody have any idea on what the heck they are doing?

Well, I have read, but can't verify it, but Mollies can change sex.

Usually female to male and they have to be young to do it.

I just lost a young female Swordtail (Platy) which I believe was changing
into a male, but it died a couple of weeks ago so I didn't actually witness
it doing it.

This *could* be what is happening, or perhaps the males are just randy and
need some female action? ;)

Oz

--
My Aquatic web Blog is at http://members.optusnet.com.au/ivan.smith

[NetMax]

"Cory" > wrote in message
news:GCtYd.62307$SF.43795@lakeread08...
> We just picked up our two gold sailfin mollies from a friend who was
> fish sitting for us while our new tank cycled. We had only had them
> for a short while before our ammonia spiked and started killing some of
> our other fish. That's when we decided to let a friend fish sit the
> two mollies because we really liked them and didn't want to lose them.
> Anyway, our tank finally completed it cycle a few days ago so we picked
> up the mollies today. One of the mollies is constantly chasing the
> other, nipping (or at least it looks like nipping) at it underneath.
> They are both males and I don't recall them doing that before we took
> them to our friend house. I can't really tell if it's bothering the
> one being chased, but it looks annoying to me. We are new to aquariums
> so correct me if I'm wrong, but I always thought a fish would raise its
> fins when it was being aggravated. Is that true? Neither of the
> mollies have their fins raised. Anybody have any idea on what the heck
> they are doing?
>
> Thanks,
> Cory


The raised fin when annoyed is silliness. Some species will raise their
fins to threaten or fold them to show submissiveness, and others will do
the exact opposite.

Males will often not co-exist well. It's a territorial thing. Moving
them into a new territory (tank) triggered the response. If the tank is
large enough, adding many fish may dilute/dissipate the aggression.
Otherwise separate the fish if you decide that it's necessary.

Generally (speaking for myself here), by the time we decide it's
necessary, it's beyond necessary, as the negative behaviour continues
when we're not watching and is sometimes even worst.
--
www.NetMax.tk