Sexing Bettas: The Ovipositor

Sexing Bettas: The Ovipositor

Q: P wrote,

Is there any way to tell the difference between a short finned male betta and a female? I want to buy a short finned male but don’t want to end up with a female from the breeder. Thanks.

A: The difference between plakat (short finned) male and female Bettas can be a little difficult to discern if you don’t know what to look for. Fortunately, there is one sure-fire way to tell the difference.

All female egg-laying Bettas have an ovipositor. This is the tube through which the eggs are deposited and it happens to be visible on the underside of the Betta. To the naked eye it looks like nothing more then a small white dot centered behind the ventral fins. If the ovipositor is present the fish is female and conversely a lack of an ovipositor indicates a male Betta.

One thing to keep in mind is that the ovipositor may be a bit harder to see in younger females.

Female Betta splendens Ovipositor

Female Betta splendens Ovipositor

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Christie F is a Betta splendens hobbyist that enjoys spending time caring for her fish and helping new betta keepers learn the ropes. More posts by:

9 Comments for this entry

  1. sunam nath says:

    i want your help in how i can determine fighter fish male or female; and how to breed them,how much time period it takes,all you can tell me about it,i will be waiting for your answer

    • Christie F. says:

      Hi Sunam,
      There is a lot more involved with breeding bettas than I can write here. I suggest buying one of the Robert Goldstein betta books and definately join one of the many betta fish web forums. We will be adding some breeding information here but I have a lot of planning and writing to do before it is posted. As for sexing bettas, this article on Sexing Bettas IS the best method. Look for the Ovipositor. If it’s there, then it is most definitely a female. Sexing the fish solely by the fin length can be misleading. Best of luck!

  2. Katrina says:

    hello, i have 2 male betta’s and my mom has 1 i also have 3 females. i got them from petsmart, the 2 bigger ones(females) are really mean. the biggest one was beating up the smaller one. a pet store guy told me if i had 3 one couldnt take domence. so i got 3. it didnt matter, so i put the mean female with one male(named cupcake) and then the other one turned mean to the new female who is a lot smaller. so i put her with another male(the mean female) any way the female i put with cupcake is being VERY mean. she attacts him and goes at him so bad that he actually jumps out of water a little. he’s bigger then her. whats up with that? also my female who is alone(named honey) is swelled up, she wasnt when i got her, i think she has eggs. that ovipositor is VERY visable. is she ready to breed? my moms betta has a nest but is in a 2g tank. i read some where they need to be in a 10g with no rocks so he can find the eggs. is that true and how long can the female hold the eggs befor she cand breed? please resond asap

    • Noel C says:

      Hi Katrina
      I just stumbled onto this site, wish i knew about it before so i could have answered your questions sooner. I’m not sure if you have everything sorted out yet and all your fish are happy now, but just in case here goes

      It seems by your description that the big “female” may not be female after all. I’ve had over a dozen store bought bettas so far and twice now what was sold to me as a female betta ended up being a short fin male. When they are very young, short fin males are extremely hard to tell the difference from females, and even when older it’s still hard to tell. The only way to really figure it out is to check for the presence of the ovipositor and the very front fins that stick straight down(beard)

      Short fin males won’t have an ovipositor and their front fins will be much longer than a females. the fact that it is so aggressive, even to male bettas and that your actual female may now be producing eggs is a very good indication of this

      as to the questions about breeding, I’ve successfully bread bettas on four different occasions in the last 7 months alone so can help there. Sites I read on bettas make it seem so HARD to do, and other people who have bettas, and people in the pets stores are amazed at my success, because it is supposed to be so hard. i’ve never found it so at all, here’s all i do

      you need at least a 5 gallon tank and about 5 inches of water in it, a cut in half Styrofoam coffee cup for the male to build his bubble nest under and lots of fake plants. (you are right about not having rocks, as the male needs to be able to see the eggs that fall out of the nest)

      After putting in the water, place the cup on one end of the long side of the tank, and all the plastic plants on the opposite side, this gives the place for the female to hide when she needs to. Put the male in the tank first and let him explore and swim around for about an hour or so, then fill a glass jar 90% full of the same water he swam in and put the female in this, then put the jar in the middle of the tank. The male should see the female clearly

      Wait about a day or so, then simply empty the jar with the female into the tank. you should cover the tank with paper or something, leave them in private, only to disturb them once a day at most to drop just a very few pieces of food in, less than 1/4 of what you would feed them, other wise leave them alone in semi darkness for another day or two, then undo the paper around the tank just enough and try to peer under the cup, if it is full of bubbles that’s good, watch to see what happens, if the male keeps chasing the female away from the bubble nest that means they mated and there are eggs, if the male allows the female to approach the nest, there are no eggs yet, keep watching and you may be lucky enough to see the mating embrace, it’s actually really beautiful how the male wraps his body around the female and supports her.

      once you are sure there are egg in the nest, remove the female. in another few days the eggs with hatch and you will see VERY VERY small fry. wait another day or two then remove the male also

      it doesn’t always work, like humans, not all males and females get along and are attracted to each other. I’m 4 for 6 attempts right now, but still a good average…

  3. anonymous says:

    Hi!I just got a new male Betta Fish and I want to move him into a tank.How do I do that without killing him?

  4. betta fish says:

    Hi

    With out question the best and mst reliable way to sex a Betta.

    Nice image and documentation

  5. Alena Elliott says:

    Ok, I have a Male Beta Puffy that is 2 years old. My Mom loves him so she went and bought 2 male betas. So we thought. The One has a tail shaped like a fan with very long finns Red, the other blue is a standard Male Beta. However We have them in a hotel style tank, and The one with long Fan shaped finns (red) appears to have a belly full of eggs, and My 2 year old male Puffy has built a bubble nest. Is it possible that although my moms new fish was labeled male it is a long finned female? The other 2 go around puffing up at it all the time and this one rarely ever puffs up, just watches them. Thank you

  6. PanthalassaRex777 says:

    Help! I have 4 female bettas, and I’m trying to establish a “pecking order”, but i took a good look and now I’m not so sure that they’re all female. I think 2 of them might be plakat males, and they’re all very young.

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