The swordtail Xipho fish, also known by their scientific name as Xiphophorus hellerii, are originating from the Atlantic zone of Central America, specifically from northwestern Honduras and Guatemala, however, in recent years it has also been introduced to South Africa. These creatures typically inhabit rivers and streams with gentle, clear currents, rocky and sandy bottoms, and abundant vegetation.
The swordtail fish, are characterized by having an elongated and moderately robust body shape, with a slightly wide caudal peduncle, very similar to that of the platty, although a little more elongated. It differs from these other fish, by the sword and the lower rays of its tail fin, which is very noticeably elongated in males, for which they adopt the name of the sword tail. The color of this tail fin or sword, usually has a black border at its base.
In the wild, that is, in its natural habitatThese animals have a green coloration, with a red stripe that runs through their body, from their eyes to the tail. The sword is usually of different colors, it can be yellow, orange, red, green or simply have different stripes of all these colors combined. It should be noted that the coloring, in the animals that we normally acquire in a pet store, is usually totally different from this one, having an infinity of colors such as albino, red, orange, black and other types of varieties.
If you are thinking have this little animal in your aquarium, it is important to keep in mind that due to the harassment that females receive during courtship by the male, it is only recommended to have 3 females for each male. Likewise, the aquarium should have more than 100 liters, with a temperature ranging between 20 and 28 degrees Celsius, with a pH between 7,0 and 8,0. Likewise, it is important not to forget the decoration of the pond, which should be based on many natural plants, rocks and different places for the little fish to hide and feel safe.
Distribution, habitat and behavior
Xiphophorus It is a genus widely distributed on the Atlantic slope of Mesoamerica, with species that range from Mexico to Honduras. In the wild, xiphos frequently calm, shallow waters with dense vegetation and sandy, muddy or rocky substrates; they also appear in streams, lakes, ponds and swampsSome populations tolerate slight salinityThey are fish gregarious: groups with many females and few males, very active and persistent jealousy.
Morphology, sexual dimorphism and varieties
They present body elongated and robust, with the characteristic extended lower caudal lobe of the male forming the "sword". The dimorphism is marked: males are larger colorful and with gonopodium; larger and more robust females. In nature, greenish tones with a longitudinal reddish stripe predominate; in aquariophilia, there are numerous color varieties and fins (red, orange, black, albino, lyretail, veil), the result of selective breeding. Natural hybridization between species of the genus is infrequent, although it can occur in captivity.
Aquarium parameters and keeping
To minimize stress, keep the ratio of 1 male for 3 females and offers swimming space. A tank from 100 liters is suitable and, if it is communal, a length close to 1 meters. It is convenient cover the aquarium because they can jump. It provides dense plants (shelters for females and fry) and open swimming areas.
- Temperature: 18–28 °C (stable optimum within that range).
- pH: 7,0-8,3; hardness medium-high (12–30 °dH).
- Renewal: partial changes every 1–2 weeks and good filtration with moderate flow.
- Salinity: mild tolerance in some populations, not essential.
Food and nutrition
Its opportunistic omnivores. They accept quality tropical flakes or granules, supplemented with live or frozen food (brine shrimp, daphnia, larvae) and blanched vegetables (spinach, zucchini, peas). Feed 1–2 times a day in small portions.
- supplements like Spirulina They can enhance color and improve overall condition.
- Carotenoids (e.g., astaxanthin or natural sources such as calendula) enhance the pigmentation, useful in players.
- Reproductive females require sufficient protein; levels close to one-third of the diet are adequate. Guideline feeding rates for breeders: around 3% of live weight up to date.
- In juveniles, well-formulated homemade alternatives (egg custard, etc.) can function, ensuring hygiene and nutritional balance.
reproduction and breeding
The xipho is viviparous (non-ovoviviparous): the female gestates and gives birth to already formed fry. They reach maturity early and reproduce with frequency. The gestation lasts 4–6 weeks and can be born 20–100 fry by birth. Females can store sperm for a long time, enabling successive births. Keep 1 male for 3 females, offers bushy plants and, if necessary, separates fry to avoid filial predation. It is typical for some females to display masculine traits with age; this does not imply a stable functional sex change.
Coexistence and compatibility
It is a fish generally peaceful and active, ideal for communities with species of similar size and temperament: guppy, mollies, platys, small tetras, zebras, among others. Males may display rivalry; avoid multiple males in small aquariums. As they occupy mostly the Middle area, rarely interfere with bottom fish. Particular cases to consider: very large, very territorial or very slow species (risk of competition for food) require space and planning.
Health, prevention and treatments
With good water quality, a balanced diet, and quarantine of new specimens, their health is usually excellent. Common problems: swim bladder disorders (associated with diet/infections), infections by protozoa and monogeneans in intensive culture, and opportunistic bacteria (Aeromonas). Short baths with non-iodized salt In appropriate concentrations, they can help against protozoa/monogeneans, but should be tested first on a small number of fish to adjust the timing and dosage. Research into novel treatments exists, but their use should be considered. experimental and under specialized advice.
Conservation and impact notes
Within Xiphophorus There are species with different conservation statuses; loss of habitat and intensive water use are relevant threats. Some species of the genus have been classified as invasive outside their original range. Data on some of their natural populations are still lacking, underscoring the importance of responsible management in aquariophily.
With stable parameters, dense plants and a varied diet, the swordtail fish It offers color, dynamism, and easy reproduction, making it an excellent choice for aquarists looking for a hardy and active species.