Determining the gender of black mollys

The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.

the_elvish_misfit

Aquarium Advice Activist
Joined
Mar 22, 2009
Messages
110
Location
Rhode Island
I've been sitting and stairing at my two black mollys for some time, trying to figure out what gender they are. (never knew you could tell) Read up on the whole fan fin vs spike tube fin thing and looked at several pictures. But both of my fish (while swimming) look like they have a spike, (while stationary) look like they have fan'd fins. Anybody know a foolproof way to tell?

On one of them those fins are white. I never saw that before, does it make a difference?
 
The males anal fin will look like a spike all of the time.(Gonopodium)
If it fans out when stationary it is a female.
 
If you post a few pictures someone will be able to tell.
 
Here is a fair pic.
The one in the front is female, the one in back is male.
black-molly-7.jpg
 
If it is genetic, he could be spreading it, if he *can* get into the position..
 
If it is genetic, he could be spreading it, if he *can* get into the position..

He has to constantly keep his whole body wiggling, and even if he does, it's not like they're show fish and I may just let the fry do their thing in the tank. Nature and all that. If not we'll see what happens.. could sell em back to the pet store.
 
Back
Top Bottom