Swordtail Breeding

by Fish Tank on August 31, 2007

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.

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