Help Sexing Lemon Tetras... Do I have mostly males??

Fae

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When I got my lemon tetras, they more or less all looked the same.
It's been about 2 months, and I've fed them mostly frozen/rehydrated bloodworms, the occasional live worm or insect, and some tropical bug bites (tiny pellets). Their tank is also planted.

This has definitely caused their colouration to deepen, and they have become a lot more aggressive. I was at a loss as to why, as they are supposedly peaceful (my tank being a little overstocked atm likely contributes as well but that's another topic). However, today, I noticed that the black along the anal fine has become pronounced in 8 out of 9 of my lemons (just a few days ago it was only in 2).

Also, of note, the 8 have all been almost nipping at and charging each other. The 1 without much black is hiding in a corner, with the 2 honey gouramis checking on her periodically (it's pretty cute honestly).

Can I get some opinions on whether this is the case and I do have 8 males? How do I proceed from here? Obviously this isn't ideal no matter the tank size, and even if I were to get a bigger tank I'm not sure I could find enough lemons to make a comfortable school.
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I'm not sure how many fish I took more than one picture of or if I got pictures of everyone, but the suspected female I didn't take a picture of
 

Ghelfaire

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I think the trick with tetras is that the deeper the body the more likely it is a female. For example I have 10 black neons, the majority like 7 are skinnier than the other 3 so I know the majority are males.

(No I can't fix it for now)
 
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Fae

Fae

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Ghelfaire said:
I think the trick with tetras is that the deeper the body the more likely it is a female. For example I have 10 black neons, the majority like 7 are skinnier than the other 3 so I know the majority are males.

(No I can't fix it for now)
I read that as well, but then all my lemons are pretty round? Also doesn't explain the behaviour. Do you find your black neons to be territorial and aggressive similarly due to your school gender ratio?
 

Falena

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I can't sex them personally as I've never owned lemon tetra. But I do have bentosi tetra that are also quite boisterous and showy, this is a predominantly female group too. I think this is normal characin behaviour, as long as they're not really hurting each other. They do like some plant matter in their diet though, as they are omnivorous. So maybe feeding them a staple mixed flake/granules or some spirulina flakes on top of what they're eating could help. Heres a link I found that has a visual comparison of male and female, hopefully it might be of some use :)
 

chromedome52

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I always sexed them by candling. That's placing a light behind the fish so that the organs are outlined. Males have a pointed opaque area with a large swim bladder, while females will have a more rounded look to the internal organs, with the swim bladder narrow and sometimes in an L shape.

Incidentally, this method works for almost all the flat bodied Tetras, like Serpae, Flame, or Lemons, where there are no significant sex differences in the fin size/shape. It will also work with slightly more elongate species, like Black Neons, Glowlights, and Head and Tail Lights.
 
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Fae

Fae

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chromedome52 said:
I always sexed them by candling. That's placing a light behind the fish so that the organs are outlined. Males have a pointed opaque area with a large swim bladder, while females will have a more rounded look to the internal organs, with the swim bladder narrow and sometimes in an L shape.

Incidentally, this method works for almost all the flat bodied Tetras, like Serpae, Flame, or Lemons, where there are no significant sex differences in the fin size/shape. It will also work with slightly more elongate species, like Black Neons, Glowlights, and Head and Tail Lights.
Thanks! I'll give that a try and report back :)
 
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Fae

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Falena said:
I can't sex them personally as I've never owned lemon tetra. But I do have bentosi tetra that are also quite boisterous and showy, this is a predominantly female group too. I think this is normal characin behaviour, as long as they're not really hurting each other. They do like some plant matter in their diet though, as they are omnivorous. So maybe feeding them a staple mixed flake/granules or some spirulina flakes on top of what they're eating could help. Heres a link I found that has a visual comparison of male and female, hopefully it might be of some use :)
Thank you for the insight, but I do have a pretty decently planted tank that I always see them munching on!
 

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