Animal-World > Freshwater Fish > Livebearing Aquarium Fish > Swordtail Fish

Swordtail Fish

Family: Poeciliidae

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Xiphophorous hellerii Photo © Animal-World: Courtesy Mathew O'Sullivan

   The most popular fish next to the Guppy is most certainly the Swordtail!

   The Swordtail is similar in shape to both the Platy and the Guppy though it has a bulkier body and a "sword" extending from the bottom of the male's tail fin. Today it is often thought to be named for this "sword" shaped extension of its tail fin, but the Swordtail was actually named for the sword like appearance of the male's anal fin!

   A beautiful male sporting a "sword" tail is one of the most striking physical characteristic possible by any aquarium fish. Even though there is no apparent purpose for this tail, it is 1/4 to 1/3 the total length of the fish. The wild species have an even more majestic tail, with swords up to 6 inches (15 cm). Though the "sword" tail is shorter in tank bred specimens it is complimented by the wonderful colors that are now available.

   Like the platys, they have been interbred to produce all kinds of interesting colors and different types of finnage. Some of the more common Swordtails are: Red, Red Wag, Red Tux, Painted, Neon Green, Marigold (and wag), Pineapple, Black, Red Twin bar, Sunset, and Gold Tuxedo swordtails.

   Extremely popular because they are one of the prettiest fish, the Swordtails are also easy to breed, fast growing and readily available.They are generally peaceful lively fish that swim in loosely grouped schools. Even though they are considered a good community fish, there are potentially many different behavior patterns and temperments. The individual fish vary from peaceful harmonious tankmates to bullies. Older males especially can tend to be aggressive toward each other and other species.

   Swordtails do best in a well planted tank with lots of room to swim around. Provide floating plants to protect the young as the parents often eat their fry. Like all livebearers, they do like a bit of salt though it is not necessary.

For more Information on keeping this fish see:
Guide to a Happy, Healthy Freshwater Aquarium

Distribution:
   The Swordtails are found in Central America from the Atlantic slopes of southern Mexico to Guadamala.
   There are several color varieties of the Swordtail Xiphophorous helleri as well as a variety of other Swordtails species. The Xiphophorous helleri is the most available and the other species, though similar, are not always as large and are often more delicate.
   The Spotted Swordtail Xiphophorous helleri was introduced as early as 1864, while the popular Green Swordtail Xiphophorous helleri was first introduced in 1909.

   Swordtails come in many colors and mixtures of colors, even in wild strains, that including red, green, black and albino though the most well known is red. There are now lyretail and high-fin varieties as males have been developed with exaggerated finnage and with two swords instead of one. Even some females also now have a sword. Most crosses are between the Platy or Moonfish Xiphophorous maculatus and the Swordtail Xiphophorous helleri.

Popular cross bred Swordtails:
   The Green Swordtail has a green body with red and yellow along the lateral line of the sides. The Green Wagtail Swordtail is this fish crossed with a Wagtail Platy and the Green Tuxedo Wagtail Swordtail is this fish crossed with a Tuxedo Wagtail Platy.
   The Red Swordtail is a Cross between the Green Swordtail and the Red Platy, sporting different shades of red and called the Brick-red Swordtail and the Velvet Red Swordtail. There is also the Red Wagtail Swordtail and the Red Tuxedo Wagtail Swordtail.
   A Variegated Swordtail is a mixture of colors with no set pattern.
   The Hybrid Swordtail, is the same fish as the Salt-and-Pepper Platy. No two fish are alike but contain bits of black, red, yellow, and green blotches. If they retain the "sword" then they are called a Hybrid Swordtail rather than Salt-and-Pepper Platy.

Pineapple Swordtail (female) Xiphophorous hellerii

Size - Weight:
The females get up to 4.5 inches (12 cm), males are somewhat smaller at 4.0 inches (10 cm).

Social Behaviors:
   They are generally considered a good community fish although they will sometimes eat their own (and other fishes) fry. Occasionally a Swordtail can become a bully, especially older males.

Sexual Differences:
Only the male has the "sword" extension on the bottom of the tail fin. The male is also slimmer and has a "sword" shaped anal fin called a gonopodium. The female has a fan shaped anal fin, is rounder of body, and will have a spawning patch at breeding time.

   There is an occasional tendency for a female Swordtail to change sex and develop a "sword" on her tail, especially when old or affected by parasites. She may even attempt courtship with another female, though the majority of the time they are infertile!

Water Region: Top, Middle, Bottom:
   These fish will swim in all areas of the aquarium.

Acceptable Water Conditions:
   Hardness: 12-30° dGH
   Ph: 7.0 to 8.3
   Temp: (64-82° F) 18-28° C

Breeding/Reproduction:
   The female Swordtail will generally have between 20 - 100 fry, usually up to 80. See the description of how to breed swordtails in Breeding Freshwater Fish - Livebearers.

Availability:
   The Swordtail is readily available.

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Latest Comments
Me and my gf are starting to breed various swordtails... before I do I had a couple questions before I proceed. 1.) is highfin and sailfin the same as I heard both talked about as very good looking 2.) Lyretail males can not reproduce, is that correct? (so I can go about it from the female side) 3.) black tails ie bluewagtail is that really cancer and probably a bad idea to try to do? 4.) cause I was thinkin a highfin lyretail with the blue black coloringw ould be, well amazing so is that a possibility for a healthy fish anyone know those answers? Larry 2009-11-08
3 years ago I put a pair of green swordtails and a pair of reds into my tank and I raised many fry which have now bred further generations. I have added another red pair for genetic variety and now have swordtails of an astonishing colour mix, including red-white tuxedos, red eyes and albinos. I have one pink female! She has produced her first batch of thirty babies which seem to be either pink or silvery-white or gold! The swordtail is a beautiful and hardy species and mine are thriving in a tank with angels, albino corys, chain loaches and dwarf cichlids. The angels and corys have also produced young successfully. Tony 2009-09-18
I just started breeding all kinds of fish. Sword Tails are the easiest by far! I have 2 oranges and the mother had all orange but 1 white came out also. Anonymous 2008-11-25
Blue swordtails are actualy a blue wag and and swordtail cross ("beautiful fish" is one of the only ways to describe it). I have a small 10 gallon tank but my 15 swordtails (around that much, adults and babies combined), 1 leopard pleco, and (at least) 110 mystery snails are all happy and have learned their feeding schedule. I'm going to get a bigger tank once I have room to house more fish and hopefully get a second pleco so my plecos might breed. Josh 2008-11-24
I raise a combination of clear (almost white) albino swords crossed with lyertail reds (Lyertail Red females X Albino clear males). As the process is slow, can you tell me more of the blue swordtails Josh / or anyone else. I need more variances to deal with. The blue intrigues me. Richard P 2008-11-04
Some of the coolest comments:
I think this is a very wonderful fish. They come in all different colors and will breed easily. But if you are like me and breed your fish these are a good fish to start on. The fry are kind of hard to take care of but if you know how to do it they will probably live. They are very easy to take care of and live a while. My oldest one is almost 7 months now in a heated aquarium around 75 F and fed twice a day. He lives with a mollie, african dwarf frog, female guppy, tiger barb, red platy and 5 jumbo neon tetras.(in a 10 gallon tank) Paige Felbaum 2004-04-06
Comments Dr Jungle REALLY Likes to Hear!
Hey everyone. This is one of the best websites for pets. I use this one and 2 others. These the only 3 I use. First off thanks to this website, I have become a big help for my neighbor who I gave fish to. If you are trying to find a way to feed your swordtails (and possibly snails and/or pleco) without taking a lot of money out of your wallet, you should try feeding them blanched zucchini (I think that is how u spell it). Blanched means that you cut it into slices, put it in a pot of boiling water for about a minute, and then put it in a pot of ice cold water. It brings out the color and makes it sink. All you do is drop it in, either with the skin (for if you have plecos and snails in the tank or if you want to give more nutrients), or without the skin (easier for swordtails to eat). Josh 2009-01-29
I like going to this site for answers to my livebearer questions.I own 4 swordtails,if you include the baby fry,1 large female guppie,and 30 of her fry.People say livebearers are only for beginners,but I like having fish that are easy to breed and tell apart.I could not imagine having a tank without atleast 2 livebearers.I would like to see more pictures or swordtail colors on this site.I enjoy seeing some of the vast color types!Thanks! Sarah . A . 2004-01-18

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Author: David Brough, CFS & Clarice Brough, CFS.