Swordtail Breeding

I've never tried Swordtail breeding, so I asked someone that has, to share their experience. Ian, also know as Statico, has allowed me to use a few pictures, and answered some questions on breeding the Swordtail fish.

FunFishTank: How long have you been breeding the swordtail?

"We've had the sword tails for two months. There are two
males and two females. This is my second group of swordtail fry. The first were
born right after we got the parents and we didn't have a
chance to isolate the mother. Most were eaten by other
fish, and we've had no luck with a breeder *net* -- all of
our guppy fry and our remaining sword fry died in the net,
so we decided to get the breeder box as a replacement."

You can see the fry in the plastic breeder box.


FunFishTank: How could you tell when the female was pregnant? How many fry did she have?

"We could tell the mother was pregnant by the dark triangle
in her abdomen. The swordtails are translucent fish and you
can see eggs and then eyes as the fry form. The swordtails had 9 fry this time."

The "dark triangle" Ian refers to is the gravid spot.

FunFishTank: What did you feed the fry?

"We feed them Hikari "First Bites" fry food. It sinks slowly
and the fry love it."

Check out this one day old swordtail fry! It's 7mm (.28 inches).


FunFishTank: What type of aquarium setup did you use to breed the Swordtail? Were their any other fish in the tank?

"Our tank is a 50-gallon freshwater tank. There are 4
swordtails, 4 white cloud mountain tetras, 1 cardinal tetra,
2 zebra danios, 2 leopard danios. There was one black molly
until very recently, and we plan on adding more mollies

FunFishTank: I've heard that the female swordfish can sometimes die after having the fry. Was your female ok?

"The female looked pretty stressed when we put her in the
plastic breeder isolation box. The box was underwater
(about 1 inch), so I had to feed the mom using a tube from
a ball-point pen. I put the tube into the hole at the top
of the box and dumped some flakes into the tube. The flakes
would sink slowly and she was much happier when fed. She was
fine after having the fry."

FunFishTank: That's good to hear! You've taken some great pictures. Could you tell us how you did it?

"I took the pictures using a Nikon D50 digital SLR camera
and a 50mm Nikkor macro lens. I set the ISO to 800 (I
think) and used a wireless, off-camera flash on its
lowest-power setting. I placed the flash off to the side
with a diffuser so it would light up the box but not blind
or scare the fish."

Thanks for sharing your experience of Swordtail breeding Ian! The two tips about using a plastic breeder box, and feeding the female are good to know.

Share |
107 Comments for 'Swordtail Breeding'
    August 31, 2007 | 10:49 am

    [...] fish, the aquarium hobbyist can try their hand at raising fry. You can learn more about swordtail breeding here. These fish are able to reproduce in high numbers. Unfortunately, in the wild, they have become a [...]

    January 11, 2008 | 6:48 pm

    its friday night – Im drinking a bit and watchin my fish – excited to read about breading Swordtails – sinvce I have a male and female and the femail looks mighty pregnant – confirmed by what I read here.

    so tomorrow im running out and getting a breader box and hopefully will have 9 fry of my own

    excellent – im excited – LOL

    Fish Tank
    January 11, 2008 | 6:54 pm

    Good luck with it Robert!


    February 2, 2008 | 4:26 pm

    Do the swordtail fish lay eggs? Or do they just give birth to the fry? How long after the fry are born can I take the fry out of the breeder box? So, the other fish don’t eat them. About how small are the fry? When they are born? I hope I haven’t asked to many questions.
    Thank you.

    Fish Tank
    February 3, 2008 | 12:56 am

    Hey curious,

    They just have fry. As you can see from the picture above, the swordtail fry are very small at birth. At about 2cm or .8 inches the fry won’t fit into an adult’s mouth. That’s the earliest you could remove them. It takes about three months for them to become full grown.


    March 2, 2008 | 1:33 pm

    i need some advice…my swordtail female is pretty pregnant, but i just don’t know when to put her in the breeding pen. i’m afraid that she will become too stressed and die, and i really don’t want that to happen!!!! please help

    Fish Tank
    March 9, 2008 | 1:57 pm


    It’s probably time to isolate her. You want her comfortable, so if other fish are involved, it’s best to move her.

    June 22, 2008 | 9:54 pm

    nice article, my kids have a swordfish and they enjoyed it…

    July 12, 2008 | 3:27 pm

    my swordfish is preg. its my fist time on breeding them , how do i know when to put it in and how long for ., i dont want to loose them .

    Fish Tank
    July 14, 2008 | 8:32 am

    I’d isolate her now.

    July 17, 2008 | 5:17 am

    my sword tail is definatly pregnant is it ok to leave her in the breeder box (like one shown in pic) until she has the fry??

    July 22, 2008 | 1:07 pm

    Hi, I was wondering if someone could post or direct me to a picture of a pregnant swordtail. My swordtail had 9 fry once and I couldn’t tell she was even pregnant. I just thought she looked bigger then the male and I put her in a breeder box to read about them and examine her.. within 5 hours she had babies! So, I want to make sure I can catch it the next time!She is a dark orange/red. Thanks for the help!

    July 22, 2008 | 1:13 pm

    Ok, so I found the picture of the female “full of eggs” But I swear my fish always looks like that. Will she stop eating before birth? How long is Gestation? Typical number of fry?

    July 26, 2008 | 2:43 pm

    My swordtail had about 19 fry in febuary, so around 6 months ago. 10 of those 19 survived. My question is when can the baby’s start to reproduce?

    July 27, 2008 | 7:39 am

    I would like to know how long you should feed the fry first bites ?

    thank you in advance.

    July 28, 2008 | 9:01 am

    I need some advice…
    I have 4 swordtails. They are about 1.5″ inches long. They were born about 5months ago and now, two of them have a big belly. I would like to know if they are old enough to breed.

    July 29, 2008 | 7:07 am

    my Sword tail is prego’s and I think she is going to give birth very soon this will be her second time but I watched her last night and she was swimming vertical is this something they do I am very worried.

    Thank you

    July 31, 2008 | 12:12 pm

    Hi. I got two female swordtails (a red and a yellow with a stripe at her side) and one male (orage in color and has a stripe but it’s bolder than the females, also he has a shorter [not short] and crooked sword) The yellow female looks very fat in the white part of her belly. Did i feed her too much or is that from the babies? I noticed that after i fed.

    So my questions are –

    1. What’s up with my yellow female??
    2. What is better, the plastic breeder boxes like this one [below link] or the nets??
    3. When do i put my female[s] in the box? How big is the spot going to be when she is ready??
    4. I heard fry are good to put back in at about 8 weeks old. Is this true?


    August 2, 2008 | 11:12 am

    My female has had around 18 fry about 4 days ago :) we knew she was pregnant by the black triangular gravid spot, around a quarter inch long, but she had the fry before we knew it, so I had to catch them carefully to separate them. KAT, the reason your female is fat in the white part, IS due to the pregnancy;)We are using a plastic breeder box, and liquifry to raise the young. I also heard 8 weeks is around when I should release the little blighters, but am not sure, lol

    August 5, 2008 | 7:41 pm

    Sadly my female swordtail passes the other day. She very prego too. I couldn’t tell when to put her in the breeder box, so I finally did! And she pretty much beat herself up overnight… Oh well.. I tired. Now I have to replace her =’(

    Fish Tank
    August 6, 2008 | 10:37 am

    I’m sorry to hear that Karen :( The gestation period is about a month, and you should be ok putting the female in the breeder box within the last week. She must have really been stressed. That sucks.

    If you don’t have a bunch of other fish, you can get by without a breeder box. You just need a bunch of bushy plants to hide the fry.

    August 7, 2008 | 4:13 pm

    ok, so i read all about the pregnant fish, and i’m pretty sure mine is. but taking care of fish is new to me (i didn’t even realize i had a male AND female until someone told me!). i have two females and one male, and i have two other fish and a frog in a 20 gallon tank. do i need a breeder box?

    August 7, 2008 | 4:16 pm

    sorry, i have more questions! we’ve had these fish for less than a month, how do i know when she became pregnant (to figure out when to put her in the breeder box if need be)? also, the other female follows her around and lingers by her. is this normal? i have three plants and two rocks. is that enough for the babies to hide in?

    August 16, 2008 | 5:17 am

    I have a female Swordfish which I bought about 8 weeks ago. When I bought it I was informed that she was pregenant, she does have the black triangle you described, but still no babies after 8 weeks! I am confused!

    August 17, 2008 | 2:55 pm

    I have a lyretail sword and ive raised her fry before but lately when i put her in my breeding tank she hits the tank walls and will not have the fry til i put her back in the main tank. She has her fry every 25 days is there a reason she wont have the fry. the last batch i only had 2 and the rest died and the one before that i had 40 fry that all lived.

    Fish Tank
    August 18, 2008 | 8:07 am


    She must have been stressed. Try a few floating plants in the breeder box.


    August 19, 2008 | 9:27 pm

    Can the females hold the babies in for a certain amount of time after the normal birthing time. if so how long can they and if after so long would it be best to move her back in the main tank to relive the stress.

    August 22, 2008 | 12:01 pm

    I would like to know what t he male looks like? I’m trying to figure out how to tell the difference between male and female swordtail.

    August 31, 2008 | 10:21 am

    I have a 55gal tank with many types of fish…a lot of Plecos. I noticed one of my female swords belly was really big. Yesterday morning I was drinking my coffee and watching the fish, and I saw a baby fry born. I immediately drove up to the pet store to get a breeding container so I could isolate the female. She ended up having approximately 50 fry. I had a spare 20gallon high tank, so i filled it a little over half way and put a sponge filter with two cups of gravel out of the 55gal tank for bacteria. The fry seem to be doing fine and the mother was released back into the 55 gal tank. I was not trying to breed but nature took its course and it just happened. So i appreciate the people who wrote in previously because it has helped me learn about raising fry.


    Fish Tank
    September 1, 2008 | 5:26 pm


    Now you get to decide what you’re going to do with all those fry when they grow up :)


    September 2, 2008 | 8:21 am

    my sword fish girl is spending a lot of time in a dip in the gravel under the planting the male is horrering about i thought she maybe ill but she comes out to feed
    also good you let me know are they live bearers

    September 5, 2008 | 8:19 am

    Trade them into the pet store for supplies or new additions to the tanks. I think im going to start trying to breed different fish for a hobby. Im getting ready for a 180 gallon tank that a friend of mine is giving me. And my girlfriend wants to start a 75 gallon saltwater tank. As for the 180 im uncertain if i want African cichlids or a home for our many varieties of plecos. Im looking to breed something that is fun, not to difficult, in demand, and may have a good return. Its not about money but to support our enthusiasm for different types and varieties of fish and their behaviors. My friend told me I should do FlowerHorns. Any recommendations. Im kind of leaning towards plecos since my girlfriend seems to really enjoy the different types. One of the stores i go to said he could sell 150 green sword tails a month if he could get some quality ones. But I haven’t seen any in any of the local shops. And I very rarely see pineapple’s either. So I will keep some males and females to start with and try the local shops.


    September 6, 2008 | 7:42 pm

    I was wondering if anyone nows a site that would have info on breeding between different types of swords and possible color outcomes. I breed a blue male sword and a female marigold lyretail and one of the babies is about 2 months old now and has a purple hue around his head on belly with a stripe going vertically around its midline with dark orange on the rest of its body. At this point it shows signs of being a possible lyre tail of some sort.

    Fish Tank
    September 9, 2008 | 8:31 am

    Hi Nathan,

    A pleco tank could be very interesting. I could picture one with driftwood all over.. not just sitting on the bottom, but longer pieces crisscrossed. There’s so many different types of plecos out there. It could definitely be unique.

    Flowerhorns are obviously unique too. I don’t know much about them, such as their compatibility with other fish.

    In a pleco tank you could add “swimming fish” to liven it up if you decided to, since plecos don’t swim much. Sounds fun.

    Here’s a pic of a Golden Monkey Red Face Flowerhorn.

    Golden Monkey Red Face Flowerhorn


    September 14, 2008 | 1:03 pm

    Hi, i have started tropical fish keeping about 4 months ago, i have a variety of fish including, 2 mail swordtails, 7 females, i also had a pregnant, female she had given birth 2 37 fry i have only got 20 left i have them in breeding net, the fry are 7 weeks old but still only about 1cm long how long untill i can release them? Tank size 55 galons

    Fish Tank
    September 17, 2008 | 9:18 am

    Hi Richard,

    I’d wait if you have any fish bigger than those swordtails. It also depends how well planted your tank is. Are there hiding places for the fry?

    Hornwort is a good plant for this.


    September 24, 2008 | 3:05 am

    Hi, my female sword had 37 fry about 8 weeks ago but they dont seem to be growing very fast i feed them 3 or 4 times a day with growth flake am i doing something wrong? or do they take a while to grow?

    October 3, 2008 | 12:42 am

    i have a 55 gallon tank with 3 angelfish, 3 columbian red tetras, 2 gouramis, a red tailed shark, a pleco, a killifish, and i just got 2 female and 1 male swordtail. im wondering if so many fish will stress out my female swordtails which i hope to breed. did i overstock my fishtank, i have 14 fish? please reply, thanks

    Fish Tank
    October 3, 2008 | 1:18 pm

    Hi Mariah,

    The number of fish you have is fine, but when that red-tail black shark grows, it will become very territorial. Give it plenty of room.

    October 4, 2008 | 2:59 pm

    oh hi again, im wondering how long and how i will be able to tell my swordtail is pregnant, besides the gravid spot.

    October 7, 2008 | 8:46 am

    I bought my only swordtail less than a week & it look pregnant but i wasn’t sure. the other fishes were so against her in the tank, attack her or something. For precaution, i put her in the hatchy floating tank. to my surprise it had 15 fry.

    Q: How long does the fry takes to grow into an adult swordtail?

    October 14, 2008 | 5:45 pm

    this message is for all the people who wrote in about putting their preg. female sword in a breeder container. If you want your fish to survive and/ or not drop her young prematurely, go out and buy one of those small round-shaped flat bowls for beginners (abt $12 and 3x the size of a breeder tank), add Java moss to the bottom and make sure the temp. is not higher then 88°. The plants in the bottom will help prevent her from eating her fry and the warmer temp. will help induce labor. If you add an air stone, make sure the pressure setting is on low so the bubbles don’t interfere with her giving birth. Don’t use the small breeder tank on swords. Not many will survive the drama. Hope this helps you guys. . .

    October 17, 2008 | 10:13 pm

    hello, im wondering how long it will take to tell if my swordtail is pregnant. i have 1 male and 2 female. nether of the females looks pregnant. iv had the male in the tank with the females for about 2 weeks. is there something wrong? should i buy another female? i want them to get pregnant.

    October 29, 2008 | 5:55 pm

    I have a red swordtail which is realy fat and asume is pregnant i placd her in a breedn net. I lukd at her belly and cant c a blackspot duz this mean she is nt pregnant.she is going up and dwn the breeding net al day

    January 22, 2009 | 1:38 pm

    Hello There. My name is Monica and I’m in charge of keeping the fish in my school aquariam. It’s a relatively small tank with only 6 fish as of now, but we’ll be getting more soon. When we went to buy our fish at the local store we picked out 1 male and one female Blue Hawaiian Swordtail fish. Being teenagers and not knowing what we were doing, we simply picked the biggest fish, and it turns out the female was pregnant. I told the Librarians, the teachers overlooking the fishtank, but they didn’t believe me. So, two months later, she just had some fry. There are about 18 of them and I managed to get them into a breeded box that I had bought personally. I read somewhere to feed the fry crushed fish food, and that seems to be working so far. What I need to know is some more information about care for the fry and breeding. I heard that certain aquariam fish, once pregnant, can have multiple births within a certain time period. Will my Hawaiian Sword have more fry? and when will they be expected? Also, how fast will the little ones grow so I can release them back into the tank?

    Thank You for your help and I may be back with more questions later.

    Monica, Hamburg High School

    Fish Tank
    January 23, 2009 | 3:38 pm

    Hi Monica,

    Congratulations! hahaha

    Your fry should be ready to go back with the community in about six weeks. I’d suggest feeding them something like Hikari First Bites. Yes the female can give birth again without being in contact with a male for months after that first birth.

    Good luck… Mike

    January 25, 2009 | 12:24 am

    Hi im breeding red sword tail 2 pairs they give about 6 fry i have natural plant and snials inside the equarium i can breed them with their parents or they will be eaten and how often i feed them twice or more even

    January 27, 2009 | 4:20 pm

    one of my swords just gave birth to some fry. she did it in the middle of the night and we didnt know this one was ready to have her babies or if she was even pregnant. she is a solid red-orange color so i couldnt see a gravid spot. we were able to save 11 fry. i have a black female whoi know was pregnant, the other 2 orange i wasnt sure and a deffinate on my pineapple sword. my question is are black sword babies born clear or black? i have the black female in the floating breeder because her belly seems to have squared off. but looking at all of them today they all seem smaller. it could just be my eyes playing tricks on me though. hopefully someone has an answer for me. email me at vdubgirl4u@yahoo.com if you do.


    leilanie coker
    January 30, 2009 | 5:38 am

    I have a male and female swordtail fish. It looks like my female fish is pregnant! I still don’t see black dots, but speedo (my female fish) has been eating a whole lot! Is she pregnant or is she just getting fat? I know all about breading swordtail fish, but is she ready?

    March 2, 2009 | 10:21 pm

    Well I started a 29 gallon tank for my son and i have 2 swordtails(1male 1female),2 mollys(1male 1female)2 goldfish, pleco,1 small shark, and a tetra of some kind is that too many fish?
    Also my female swordtail was in labor and had 2 fry so I grabbed a 2.5gallon tank I have and set it up with water from my tank. I put the 2 fry in the tank because I didnt want them eaten by the others when I went back to my big tank minutes later my female was dead. Did I do something wrong?

    Fish Tank
    March 18, 2009 | 4:58 pm

    Hey Sid,

    Your fish could have already been sick. It happens. As for too many fish…. the rule is 1 inch of fish/gallon. Remember they grow.

    March 29, 2009 | 4:40 pm


    March 30, 2009 | 10:52 pm

    Hi, my female sword tail fish already has a big triangular gravid spot for about 4 days now i isolated her in a 2 gallon tank. so my question is, how long will it take her to have babies?

    March 30, 2009 | 10:56 pm

    my community tank is about 5 gallons with 1 male sword and 2 females excluding the one i isolated in a 2 gallon tank.

    oh! almost forgot THANKS in advance =)

    November 16, 2009 | 9:12 am

    hi mike.a cupple of days ago i had a fancy guppy that was going to have babys but died to soon. i wanted to get a swordtail male becuas i already have a female but just need a male, could you tell me were you got your breading tank, i would love to know. please right back soon. from summer.

    November 21, 2009 | 9:38 pm

    Okay from an earlier post one said their sword fish had 9 babies. sword tails have many many many babies at one time. I use to breed sword tail and guppies at a time. Sword tail can give birth to as many as 80 fry at one time. another post said that the fish can not fit that size fry in their mouth. they can fit the fry in their mouth. that is why the one only found 9 fry. she ate her babies. its survival of the fittest. you would be surprised what size fish one can swallow. they just have to swallow head first on larger fry. new born fry are perfect size for eating. that is why you get the breeding tanks that have a bottom part the fry swim into but the cracks to small for the mother. that way you will find you fry will be a lot more then 9.

    December 4, 2009 | 9:09 am

    my swordtail is in a pond and 2 of my female swordtail is pregnant. can i put them together in a plastic container cause i think plastic breeder box is not fit for a pond,
    and if i put them together do i need to put aquarium air pump?

    Fish Tank
    December 5, 2009 | 1:07 pm

    I’d think you could do that. If it’s a seperate unit, keep up with water changes. If the space is small, and you have an air pump, it wouldn’t hurt.

    December 7, 2009 | 8:25 am

    How many weeks before i i remove my fry to there own tank and put them to my pond with my adult swordtail?
    thank you!!!

    December 7, 2009 | 8:40 am

    How many weeks before i can remove my fry to there own tank and put them to my pond with my other swordtail to make sure that they will not will be eaten by my adult swordtail.
    thank you!!!

    Fish Tank
    December 9, 2009 | 7:04 pm

    Usually around 6 weeks, or when they look big enough.

    December 13, 2009 | 1:02 pm

    hi if anyone could tell me how long after a swordtail has there fry can she get pregant again as my swordtail had 47/48 fry about 2and a half month’s ago and they are in a tank of there own now i am almost certain she is about to give birth again i was just woundering if they can get caught about 2 week’s after having the fry. the only reason i ask that is because my male swordtail got eaten by one of my other fish 2 week’s after she had her first lot and can someone tell me how long they are preganant for thank’s ever so much i now this is alot to ask but i would really like to know asap cheer’s katy

    December 30, 2009 | 10:20 am

    hello, do a pregnant sword tail and fry need an oxygen in there own breeding area?even if i put some anarchis in there breeding area?
    thank u.. merry xmas & happy new year

    January 24, 2010 | 9:50 am

    I have two female, one is the baby of the other, and one male. The older of the two females looks pregnant again. (I can see the eggs thru the skin). The younger also looks pregnant, but I’m not sure. Niether looks very large in the belly. How long should I wait before putting them (her) in the breeder tank? The older one had a batch of fry, (the other female I have is the only one that lived), a very long while back and when I realesed her back into the tank the male became very aggressive towards her. I also have Angel fish, one glow, Barbs, Ghost fish, Plecos, and one other I am not sure of the name. Any suggestions you have are always welcome. I think I have the raising the fry thing down, but need to know when to put the mom’s in the breeder tank. Thanks for any help.

    February 3, 2010 | 6:06 pm

    hey i got a question: well the other day i got my fish set up in a good sized tank, plants, and a light. I bought red velvet sword tails: 2 females 1 male. Both the females are pregnent ! i wanted this to happen but I don’t know when to put her in a breeder box/ breeder trap. help!

    February 27, 2010 | 6:18 am

    hi.. can a guppy and swordtail live peacefully in a same pond?
    thank you..

    March 4, 2010 | 10:59 am

    i got a swordtail from my local aquarium and was told she’s heavely pregnant, i’ve put her in my breeding box but as i’m not sure how far along she is how long can i leave her in there???

    March 7, 2010 | 9:28 am

    great news my swordtail gave birth 2 around 45-50 fry 2 days ago it was a very exciting day :-) all r doing fine

    March 16, 2010 | 2:37 pm

    how do you know when a female swordtail is pregnant

    March 20, 2010 | 3:15 am

    i would like to ask how long is a swordtail’s pregnancy? i’ve got a female swordtail in my tank and would ask how long do i need to quarantine my baby fry from the adults…

    have a nice day

    March 30, 2010 | 7:34 am

    the males have a longer tail that looks like a sword when my females are ready to have babies or even look pregnet i put them in a ten gallon tank and i also have a ten gallon i put the babies in by there selfs so the dont have to hide from the adultes or get eaten i found that so much easyer oh i also have plants for the babies when the females give birth i got 29 babies kept 5 they were green sword tail s very pretty .good luck everyone.

    Fish Tank
    March 30, 2010 | 6:24 pm


    April 6, 2010 | 1:28 am

    most swordtail’s are pregnant for around 30 days give or take. i have bred 10 times now, and i love it i have had a 98% success rate of survival the others got eaten when i was a bit to slow. i can tell when my swordtail is pregnant when her gravid spot has darkened and her belly is swelling a little bit. my fish when about to give birth have an almost squared tummy, and will swim constantly up to the surface of the tank then back down to the bottom, repeatedly. that is how i know to get another tank ready and separate her from the other fish. as soon as they are born i remove her from the tank and put her back with her friends. i usually feed the fry a little bit of blood worms when i’m giving my other fish some and really crushed up normal flakes. just make sure though you don’t give them to much as it will pollute the tank which can cause diseases and in some cases death.
    i hope that has been helpful.

    April 6, 2010 | 1:31 am

    i would quarantine them for at least 2 months until they’re big enough to not be eaten.

    April 6, 2010 | 1:35 am

    also i find swordtail’s a little aggressive if in a smallish tank with guppies. if you want a harmony’s tank then get a bigger one with a lot of space that can be split into territories by your fish. if you have any question please write to me at bookwormbec at gmail.com

    April 24, 2010 | 9:36 pm

    can oronge sword tails go with out food for four days? im going on a trip and im trying to figer it out

    May 6, 2010 | 11:19 pm

    it’s just so fun to see the fry .its

    Fish Tank
    May 12, 2010 | 12:33 pm

    Thanks for the great info Rebecca.


    June 11, 2010 | 4:13 am

    I have a 600l heavilyu planted tank with 6 swordtails (3male 3female) plus many other tank mates. I bought them about 2 weeks ago, and a few days ago i noticed one of my females getting quite fat. then i noticed the dark spot so i decided to do some research. after finding out she was definatly pregnant i put her strait into a seperate tank on her own and blow me, the very next day she had lost her fatness and i noticed about 20 babies swimming around. From what ive read this was very lucky as its really hard to tell when therye gonna drop. i seperated the female strait away and she seems fine. the fry tank is set up so that water from the main tank flows in and gets syphoned back out into the main tank. as far as i know they can be fed crushed flake immediatly. I’ve only ever managed to breed my paradise fish, and this was only recently, they were very interesting to watch! building there nest and watching them court. also from my research i know that swordtails remain pregnant after they have given birth, and will spawn almost monthly, storing the sperm from one mating encounter enables them to have several pregnancies, so i will be keeping my eye on her. she does still have the dark spot near the anal fin and its a few hours since she gave birth, but its not as clear as it was lastnight, and she has lost the round belly, so im sure she has finished spawning for now. Its a really rewarding experience bringing up fry and from what i can tell, swordtails breed more easily than any other fish…. u dont even have to try! I think my female must of been pregnant when i bought her, this is very common.

    June 11, 2010 | 4:31 am

    forgot to add, the pregnant fish is a pineapple sword, and i suspect the male pineapple sword is the father as they have been very close recently. there is also 1 orange wag (male) 1 green (male), 1 gold painted (female) and 1 pineapple painted (female)

    Fish Tank
    July 27, 2010 | 1:00 pm

    Congratulations Russell!

    August 7, 2010 | 2:46 pm

    ok, i just got 2 swordtails today and i didnt realize until i was almost home that one of them was pregnant. i dont have a breeder box, but the only other fish i have are 2 zebra danios and a plecastymus, could i get by with out a breeder box???

    Fish Tank
    August 8, 2010 | 6:53 am

    Those other fish aren’t aggressive. You need plenty of hiding spots for the fry, and have to remember the adult swordtails could eat them too. Can it be done? Yes. But it’s more risky without a breeder box or breeder net.


    August 31, 2010 | 11:13 pm

    hello ive got swordtails girls and boys i had a litter of fry every month for 4 months running the most she had was 48 one time also ive breed my mollys a couple of times and platys once and plecos now im breeding my guppys
    its so cool waiting and finding the babys in ur tank trying to catch them working out who they came from

    Fish Tank
    September 1, 2010 | 3:59 pm


    Sounds like you’re having fun with it.

    September 13, 2010 | 5:49 am

    hiya,ive got a 65 litre tropical tank,having bought 2 swordtails,1male an 1 female i notices the female was very bnig and i can see the gravid spot at the lower abdomen,i isolated her in the breeder net but see looked stressed so i released her after two days, she still has a big belly an gravid spot but still no babies!! how do i know when she is about to give birth? and can she put the birth off for a matter of time?? please get bk in touch as i do not know when she is about to pop and i just dont want isolate her like 2 weeks before she gives birth if ya know what i mean

    September 28, 2010 | 4:07 am

    I have a male and a female swordtail, and recently have thought she could be pregnant, she just started getting bigger and bigger. Shes not humongous at the mo, but when u c her front ways, she looks abit like a balloon lol. Thing is, i can’t be 100% sure, because i can’t c a gravid spot, and the reason for that is that she is black, (orange on the top) So how do i know if shes prego and not just fat (altho she shouldnt b fat, i dont overfeed her).

    October 10, 2010 | 8:53 am

    can a red eye swordtail fish live a pond with out an air pump but a there is a lot anachris?
    thank u!!

    October 29, 2010 | 9:24 pm

    You you could change the post subject Swordtail Breeding | Fish Tank | Tank of Fish to something more catching for your content you make. I enjoyed the blog post however.

    January 2, 2011 | 2:46 pm

    I have a question: is it possible for swordfish to have differn’t colored fry? When I mean by that I mean if a red and white swordfish had fry, would the fry be pink once they become adults? the reson is i tried that, and the mother died while preg.

    February 10, 2011 | 3:21 pm

    My swordtails just had a brood, thats actually how i found this website. I had a Kribensis African cichlid in the tank with it and the kribensis ate most of them during the night, when they actually came out. But i was able to get four of them out of the tank in time luckily, i am kind of confused on how to feed them. one friend said put lettuce in and stuff will grow on it that they love, but everywere on the internet says just crushed up fish food. The water hardness is very low (i read in a book that helps young fish and plants) and the ph is just right, and im trying to keep the temperature at about 72-ish but i dont have a thermometer for them. If you have any suggestions please reply. Thank you for the post!

    February 12, 2011 | 9:05 pm

    I had my male pineapple swordtail for about 2months. The guy at the fish store said he will only breed female pineapples however, when I brought home a female red velvet, he was a happy fish! About two months after that, I noticed an orange fish I never saw before and it was a baby swordtail! It was about a third the size of the mother when I finally noticed it. I couldn’t even tell she was pregnant and I have no idea how many fry there were. The baby looks exactly like the red velvet mother now, I call her a teenager, now about half the size of mom. I don’t seperate my mom at all, I watch the pineapple breed her all the time and I decided to keep it natural as long as mom doesn’t look stressed. May not end up with as many as fast but survival of the fittest is ok by me. Also have baby plecos now! Haven’t even tried for that!

    Fish Tank
    March 6, 2011 | 2:41 pm

    Crushed up food should be fine. Sounds like you are doing ok!

    April 26, 2011 | 3:25 pm

    Well i am used to raising Fancy Guppies (and raising swordtails and Platies seem to be the same).. I do it a little different to reduce the amount of fry eaten by the Adults..

    My Green Swordtail female just gave birth to about 42 fry, i stopped counting at 42.

    I have 4 Tank set-ups

    *I have a 2.5g raising tank, heavily planted and some java moss at one end.(gives then organic matter to nip at and also fiding places)

    *I have a 10g plant ONLY tank, that has a lottt of cover and driftwood

    * i have a 5g tank that doubles as a Qurantine tank…

    *and i have a 20g Display tank.

    The 20g is a mixed community tank, once the “loving” is done and the female/s are gravid (pregnant). I will pull the female once i can view the eyes of the fry and the gravid patch starts to get dark and place them in the 10g PLANT ONLY tank if there is only one female at that time (if there are 2 i will put them in the 10g in a divided breeding trap with a open grid bottom… in this case the fry will fall through into the tank and away from the mother… i will also do this if i will be away for more then 24 hours and can’t check every 3-4 hours.).. I check the tank about 3-4 times a day (or every 4 hours). My daughter helps with this part lol. This way you sometimes catch her in the act of giving birth (it’s a good lesson for the kids and also for Adults). The fry are free swimming as sooon as they are born.

    The mother will not start to eat her fry till she is done giving birth (usually 2-3 hours) which falls right in with your “check-ins”.
    Once she has given birth, i take hor out and place her in the 5g tank to relax b4 returning her to the 20g Display tank.

    I then net or syphon the fry from the 10g and place them in the 2.5g where they grow out….. i usually have a batch of fry every 2-3 weeks .

    I let the fry grow out to about 2 months in the 2.5g, and keep about 2-3 from each batch that have the best color and health and thoes lucky ones goes into my 20g Display tank and into my breed stock.

    The rest are given away to friends or sold cheap to local pet stores.

    Hope that helps.. I have pix of the whole deal if anyone would like to see. Please e-mail me at JonRich918 [at] aol.com and i’ll respond with pix.

    Fish Tank
    April 30, 2011 | 3:22 pm

    Hi Jon!

    Thanks for the detailed system! It’s good to get different ideas on technique.


    May 25, 2011 | 7:25 pm

    hi there, i know this may sound cruel to some, but have you found it ever necessary to cull any of the young off due to deformities or unnatural growth development? I am new to owning tropical fish, and have just finished setting up and stocking a 90L tank about half a month ago. I have just bought a breeding tank for my pregnant swordtail. I would just like to be prepared for the worst that may happen.


    August 3, 2011 | 7:30 am

    helloo, I have 2 guppy males, and 4 guppy females. one of the females looks pretty pregnent. the belly is pretty big, bigger than the others. and i see the gravid spot, but I dont know when I should put her in a breeding box? please answer me. i realy need some help. thanxx for the answers!! :)

    Fish Tank
    August 4, 2011 | 8:38 am

    Put her in now.

    November 8, 2011 | 4:32 am

    i have a female swordtail and a male.
    the female has a large white belly and the male chases her.
    do you think she is preg.

    December 9, 2011 | 12:34 pm

    I have 2 male swordtail, 1 female + 16 small ones, 2 butterfly + 4 small ones, 2 plecos. I just got the swordtails and butterfly. Since they came I notices my gouramies have gone missing and 2 of my swordtails and 1 butterfly. Could these new fish be eatting my female fish?

    Faith Moua
    December 16, 2011 | 8:14 pm

    Hello And thanks for telling us on how to do this, but I’m a little butt cinfuse on how you fed the mother still and when and how do you knao when the mother is going to have her fry and I really need help so when your fish is preg. Again can you make a YouTube on how you did it and other stuff? Cuz today I just notice that my fish was pregnant and my fish is a neon tetra fish and she lives with my goldfishes and I really need help so pls apply to this ASAP!! Thanks

    December 19, 2011 | 7:27 pm

    i need major help… i just bought four green swordtail fish, two males and two females. the only kind of fish i have ever had is gold fish which do sharethe tank with the swordtails and they get along great. but heres the problem, number one both of my females are pregnant, one very much so. two i have no clue what i am supposed to do, feed them, where to keep them, how long to keep them there, or anything. i have surfed the internet all day with little to no answers, just that the female should be seperated. any help is greatly appreciated. my husbad and i are working on a huge tank collection but i dont want to neglect these fish when they are in such delicate state.

    December 28, 2011 | 10:46 pm

    Hi I have 2 swordtail fish and I haave 3 black tiger striped fish and I had 3 neon guppys. The swordtail is pregnint she hates the breeding tank what should I do? The tiger fish might eat her or the fry they already ate 2 of the neon guppys

    Sincerely, guppylover

    January 14, 2012 | 10:36 pm

    This is my first time with life bearers. I have swordtails, tuxedo platys and Dalmation Mollies. They all seem to be getting on well. But the swordtail female bothers me greatly. She appeared slightly pregnant when I brought her home from the petshop. However, it’s been near two months…and she doesn’t appear to be having any babies. SHe is still quite pregnant looking, and I don’t know what is happening with her. She’s been pregnant wwaaaaaay too long. What should I do.

    February 29, 2012 | 12:29 am

    i have 2 swordtails in my backyard pond(1 male, 1 female) and some large goldfish. the other day i noticed some fry in the pond and scooped them into a tank. there are about 20 of them and they are all the same size. i thought they were swordtails but there are a lot of them. do you think they would be swordtails or goldfish?

    Karen J
    September 18, 2012 | 8:52 am

    I just bought two koi swordtails, male and female. I was positive their would be no problem breeding them since it was so easy with mollies in my thirty gallon. I have had them for a week now and it seems as though the female has an extreme hate for my male.. she chases so much sometimes he doesn’t want to swim any more…. I have them in a 10 gallon, is this enough room for the two of them? could she be stressed if he is not ready to breed?.

    does my fish have problems????

    Fish Tank
    December 31, 2012 | 6:28 pm

    There’s a definite stress problem there. A bigger tank may help. She may also just be tired of the male pursuing her. That should be happening.

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