Sexing Jack Dempsey's

[dolphinfan]

I've read so many different post's. Which one is right ? Are they sexed by the color on their gills ? Or are they sexed by the length of their dorsal fins ? Or by the pointedness of the dorsal fins ? I have 4 youngsters in a 55gal right now.. I'm thinking I have a pair, they are always together and always put the run to the other 2. One has color on the gills , the other doesn't, ones dorsal fin is pointed the other is not. How do I sex these fish ? Any help would be greatly appreciated. Thank you.

 

[AndrewLang26]

The color on the gills theory isnt always right, but I would say most of the time it is...You have to take them out and vent them...Look at their belly and look right behind the anus if it's round it is female, if it is pointed it's male.

it is not easy though...

 

[Toby_H]

Females almost always have blue blotches on the bottom of their gill plates. When they are young this may be hard to detect, but as they mature it will become apparent.

Males almost always have pale or blank bottoms of the gill plate. Occasionally the blue spangles from the body will go all the to the bottom of the gill plate.

The difference is subtle, but there is a difference between blue blotches and blue spangles. If you look at enough examples of proven males and proven females you will be able to learn how to distinguish each.

Fin shape has little to nothing to do with gender. It has far more to do with genetics. Fin shape displaying gender is simply an 'old wive's tale'.

Above I say "almost always" more so to prevent arguments from someone with an immmature fish that has yet to develope into what I described, than it is to suggest not all Dempseys fit my description. Although I do admit there are rare cases where even the most experienced Dempsey keepers can mistake a spangle for a blotch or vise versa.

 

[cichlidgirl]

If you go to utube or flicker and search jack dempsey , or jack dempsey breeding etc.. there are a couple examples of male and female pairs , you can see the differences on real large adult fish. Nearly all i have looked at show a male with a big blank area on the lower gill plate/jaw area. Its very noticable . All the females i saw showed lots of blue or green spangles all over the same area, almost glowing with them compared to the males. It would be real hard to tell for sure on tiny juvies (like my 1 inchers) but once they get 3 to 4 inches it seems like its more noticable and by the time they are over 5 to 6 inches its real noticeable. Hope this helps.

 

[urbaninja]

Females almost always have blue blotches on the bottom of their gill plates. When they are young this may be hard to detect, but as they mature it will become apparent.

Males almost always have pale or blank bottoms of the gill plate. Occasionally the blue spangles from the body will go all the to the bottom of the gill plate.

The difference is subtle, but there is a difference between blue blotches and blue spangles. If you look at enough examples of proven males and proven females you will be able to learn how to distinguish each.

Fin shape has little to nothing to do with gender. It has far more to do with genetics. Fin shape displaying gender is simply an 'old wive's tale'.

Above I say "almost always" more so to prevent arguments from someone with an immmature fish that has yet to develope into what I described, than it is to suggest not all Dempseys fit my description. Although I do admit there are rare cases where even the most experienced Dempsey keepers can mistake a spangle for a blotch or vise versa.

Very well said.