Inter-sexed bettas?

[lrl251]

Hi everyone,

I'm a novice fish keeper. I recently read an article (https://www.theatlantic.com/science/archive/2021/05/betta-fish-sex-determination/618889/) that talked about how male bettas can sometimes by XX and females can also be XY. I'm not an expert on genetics so I was wondering if anyone knew if there are visible signs of a male or female presenting betta carrying the opposite chromosome? I've had two bettas that looked almost like they were a mix of both sexes. I have a beautiful male betta with a large belly area (it's not bloat and he's not sick), and who seems to be missing his beard? Even his ventrals seem a little bit suspect, but his anal and caudal fins definitely look male. After reading the article, I started wondering if maybe I had a male who used to be a female? Or is it more likely that I just have a feminine-looking male betta? I've also had females that I was told look like males but I'm not sure if the XX/XY change works that way. 

[Fish Folk]

On 6/17/2021 at 5:44 PM, lrl251 said:

Hi everyone,

I'm a novice fish keeper. I recently read an article (https://www.theatlantic.com/science/archive/2021/05/betta-fish-sex-determination/618889/) that talked about how male bettas can sometimes by XX and females can also be XY. I'm not an expert on genetics so I was wondering if anyone knew if there are visible signs of a male or female presenting betta carrying the opposite chromosome? I've had two bettas that looked almost like they were a mix of both sexes. I have a beautiful male betta with a large belly area (it's not bloat and he's not sick), and who seems to be missing his beard? Even his ventrals seem a little bit suspect, but his anal and caudal fins definitely look male. After reading the article, I started wondering if maybe I had a male who used to be a female? Or is it more likely that I just have a feminine-looking male betta? I've also had females that I was told look like males but I'm not sure if the XX/XY change works that way. 

Interesting question! While it is true that nature certainly has surprises, I suspect that this scenario is highly unlikely for most hobbyists to encounter. Sexing Betta Splendens has less to do with analyzing fin shape and structure and more to do with observing the presence or absence of a white egg spot visible on mature females protruding from her abdomen just behind the pelvic fins.

For example, there is virtually no way to certainly know the sex of this Betta pictured here just from this angle. Is this a short-finned male? Or a female?

But if observed patiently, an egg spot can be seen

Now, I’d hasten to say that there are really unique possibilities, which your linked article alludes to. Switching species — if I recall correctly, swordtails have been known to flip sex in a group if there is no apparent way for them to multiply.

Edited June 18, 2021 by Fish Folk

[ARMYVET]

@Fish Folk Wow nice Betta....I would love to a pic of that whole tank...It looks wonderfully landscaped.

[Fish Folk]

On 6/18/2021 at 7:29 AM, ARMYVET said:

@Fish Folk Wow nice Betta....I would love to a pic of that whole tank...It looks wonderfully landscaped.

Here you go...

 

[ARMYVET]

On 6/18/2021 at 7:31 AM, Fish Folk said:

Here you go...

 

Awesome....that was a real treat to watch....Great Betta...Great tank....and Awesome video. Thank you!

[Sarina]

On 6/17/2021 at 4:44 PM, lrl251 said:

Hi everyone,

I'm a novice fish keeper. I recently read an article (https://www.theatlantic.com/science/archive/2021/05/betta-fish-sex-determination/618889/) that talked about how male bettas can sometimes by XX and females can also be XY. I'm not an expert on genetics so I was wondering if anyone knew if there are visible signs of a male or female presenting betta carrying the opposite chromosome? I've had two bettas that looked almost like they were a mix of both sexes. I have a beautiful male betta with a large belly area (it's not bloat and he's not sick), and who seems to be missing his beard? Even his ventrals seem a little bit suspect, but his anal and caudal fins definitely look male. After reading the article, I started wondering if maybe I had a male who used to be a female? Or is it more likely that I just have a feminine-looking male betta? I've also had females that I was told look like males but I'm not sure if the XX/XY change works that way. 

Alex talked about this a few weeks ago on a live stream, super fascinating subject! As for your betta, I think it's totally possible to have an intersex betta, however you really can't know for sure, since appearance can be so deeply varied. The only way to truly tell is to have a genetic test done... Difficult on a small fish, for sure.