The swordtail fish, also known as Xipho, Sword Bearer or by their scientific name Xiphophorus hellerii, belong to the Poeciliidae family and the Cyprinodontiformes order. They are native to streams, rivers and lakes clear waters with gentle currents, present especially in MesoamericaThey are characterized by their robust tail; in males, the lower rays of the caudal fin are extended to form a "sword", a trait that gives them their name.
La coloration In nature it is usually olive green with a brown or reddish lateral stripe. In aquariums, thanks to selection and crossbreeding, they appear multiple varieties in shades of red, orange, and black, as well as albino and neon forms. Lines such as tuxedo, wagtail, hi-fin, and lyretail also exist. In the aquarium, they can appear more vibrant if provided with a varied diet and good water quality.
It should be noted that Males They can measure up to 8 cm without counting the sword, while the females They are usually somewhat larger, reaching up to 12 cm. They present sexual dimorphism: Males display the sword and gonopodium, while females do not; the latter tend to be more robust.
If you plan to have them in your aquarium, the temperature should be kept between 20 and 28 ºC and the pH between 7 and 8,3. They appreciate aquariums with space to swim, abundant vegetation and somewhat dark backgrounds.
Key features, size and life expectancy
In addition to their stylized silhouette and slightly raised mouth, swordtails are active swimmers of the middle-upper spine. Under optimal conditions, its Life expectancy It is between 3 and 5 years old. Females usually grow slightly more than males, who may show high back muscles in certain selected varieties.
Water parameters and aquarium size
They adapt to a wide range: 18–28 ºC (65–82 ºF), pH 7,0–8,4 and hardness 12–35 dGH. The ideal is to maintain stable values and avoid peaks of ammonium, nitrites or nitrates. For a single specimen, you can start from 60 liters approx., but for groups it is recommended 80–120 liters or more. A filter with good flow and oxygenation promotes their well-being.
Decoration, plants and security
The essential thing is free space for swimming and areas with shelter plantsSpecies such as work very well. Java fern, Anubias o dwarf hairgrassYou can add rocks and logs, leaving the center clear. A secure lid: They are powerful jumpers.
Behavior and tankmates
Its peaceful and perfect for community, although males may show some territoriality with each other. Keep a ratio 3–4 females per male and groups of 4–6 or more. Compatible with fish of similar size and calm temperament (e.g., corydoras, tetras that tolerate neutral-alkaline pH, small rainbows). Avoid nippers and very aggressive species.
Recommended diet
As omnivores, they appreciate flakes or pellets rich in nutrients, more seaweed wafers and blanched vegetables. Complement with brine shrimp, daphnia or mosquito larva (live, frozen, or freeze-dried). Offer 2–3 small feedings a day and remove any excess to avoid spoiling the water. juveniles require a little more protein for good growth.
Health and disease prevention
Its rustic, but susceptible to common problems such as I (whiteheads) or “cotton wool” type fungal infections. Prevention is based on Thermal stability, control of ammonia/nitrites and regular water changes. A test kit helps detect deviations before outbreaks occur.
Reproduction
Its viviparous and reproduce easily. Gestation can last from 26 to 63 days; the female can store sperm and give birth to several litters without remating. To maximize survival, enable a breeding aquarium with fine plants and a stable temperature of around 25–26 ºC, and remove the adults after birth. The fry accept infusoria, powdered flake or brine shrimp nauplii. Control the population to avoid overloads and consider the hybridization with platys if they live together.
Responsibility and conservation
They have established themselves in various countries outside their natural range; avoid releases to the environment so as not to affect native species. Keep quarantine for new specimens and seeks genetic diversity when breeding to reduce potential health problems due to inbreeding.
Although simple to maintain, swordtails shine when their need for growth is respected. stable water, varied diet, swimming space, and a balanced social structure; this way, they show their best color and active, engaging behavior.