platy fish

Question
I have a 10g tank with one gold dust molly, 3rasboras, 4 platy.  All I was told are male but with the platies they seem to be "picking" on this one platy.  I think they are all male but I
am not so sure....this is my first try.  Two questions: how do I tell if they are trying to mate with this one platy? and how do I tell the sexes of them?

Answer
Hi Sandy;

Take a peek at the bottom rear fin. The female's is fanned out and the male's is more pointed. Here is a link to a picture of how to tell the difference;

http://img.photobucket.com/albums/v106/Frankslapperinni/Fish/Platy_sexing.jpg

If it turns out that you have one female, a change will have to be made. Those males will harass her to death. There should be at least two females per male to avoid that trouble. You could exchange her for a male at the fish store, or just return her so she won't be in so much danger any more.

If it turns out they are indeed all males, your others are simply being bullies. Provide more places to hide and if necessary, you could move the one out. Sometimes those little fellas are just looking for trouble when there are no females around. They live to breed and that energy has to be used somewhere. ;-)  

At Your Service;
Chris Robbins