# Sexing Jack Dempseys?



## skools717 (Mar 29, 2008)

I was intrested in getting a pair of JDs and was wondering how do you sex them??


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## Toby_H (Apr 15, 2005)

Females have blue splotches on their gill plates... males have pale gill plates... males also have more spangles but sub dominant males may not develop them...

The "gill plate" is the flap that covers the opening on the gill...

Sexing by spangles is poor at best... In wild caught specimen it may be true that long pointy fins are more common in males and a squat body is more common in females... But I currently have males with few spangles and blunt fins... as well as elongated females with lots of spangles...

I've never seen a male with blue on their gill plate or a female with a completely pale gill plate (unless stressed)...

Here is a beautiful female with tons of spangling and a nice long body... pointy fins too...









Here is a nice shot clearly displaying blue blotches on the gill plate...









Here is a male in breeding dress, the bottom of his gill plate is dark as he was spawning but there is no blue at all...









All the fish pictured are several years old, young females may have not yet developed the blue and young males may have spangles close enough to the gill plate to be misleading...

When selecting a hopeful pair from a group of juvis... Find out what day your preferred LFS gets Dempseys in... if they arrive in the morning (typical), show up that evening and check them out... Find the absolute darkest fish, it should have some nice blues in her and a noticeable red line along the top fin... Then find the slightly larger fish that looks like he is showing off to her a little bit. It should almost look like they are working together (they are)... There's your pair 

I would expect to see this kind of behavior at about 2.5"... if your selection is smaller than this I doubt you will have much luck identifying genders... if they aren't acting like this at 2.5" Personally, I'd go to another store...


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## cage623 (Feb 2, 2008)

I have always heard this but never really thought about it too much. I guess it is way easier to picture with... well pictures. :lol:


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