Lyretail Swordtail

The Lyretail Swordtail is a selective breeding form of Xiphophorus hellerii, distinguished by the specific structure of its caudal fin. Unlike the wild type, where the lower rays form a single long "sword," in the lyretail form, both the lower and upper rays of the caudal fin are elongated, giving it a fork or lyre shape. The fish's body is elongated, laterally compressed, and its coloration varies from the classic olive-green with a red stripe to vibrant selective colors such as red, black, or calico. Males reach 7–10 cm in length, possess a gonopodium, and have more pronounced fin development, while females are larger and have a more rounded abdomen.

The wild form inhabits waters of Central America (Mexico, Guatemala, Honduras), populating both mountain rivers with fast currents and stagnant waters such as swamps, lagoons, and lakes. The lyretail variety is a product of aquarium selective breeding and is not found in the wild. In the aquarium, these fish prefer the middle and upper water layers, needing space for swimming and dense vegetation for cover.

These are active and peaceful fish, suitable for community tanks with similarly sized species. Within the species, males can exhibit territoriality and aggression towards each other, so it is recommended to keep them in groups with a predominance of females (a minimum of 3 females per 1 male), which helps to disperse the attention of the dominant male. The fish are active and can jump out of the water, so the aquarium should be covered with a lid.

Thanks to their natural resilience and lack of special requirements, Lyretail Swordtails can be a wonderful addition to any freshwater or brackish aquarium. The only thing to consider is the choice of tank mates: it is undesirable to house them with large and aggressive fish. Special attention should be paid to cohabitation with certain types of barbs, which are known for their tendency to nip and damage the fins of other fish, especially if they are long. Even a beginner aquarist can easily manage their care, as it presents no particular difficulties. It is only important to provide them with high-quality and balanced nutrition, maintain stable water parameters, and regularly remove excess organic matter, such as food debris and waste. We recommend trying Aqvium flake food for aquarium fish, our new bestseller on Ozon with a rating of 4.9. This food is perfectly suitable for most aquarium inhabitants. Its raw materials are produced in accordance with new European standards (EU 2018/848) and are enriched with vitamins A, C, D3, E, as well as Omega 3-6. You can purchase it on Ozon.

Swordtails are omnivorous fish with a strong inclination towards plant-based food. Their diet should include high-quality dry foods (flakes or granules), as well as regular additions of live or frozen foods (brine shrimp, daphnia, bloodworms). Important components are vegetable supplements: blanched zucchini, spinach, or spirulina-containing foods. Feeding should be done 1–2 times a day in small portions that the fish can consume within a few minutes.

Along with many advantages, this breed of Lyretail Swordtails has inherited certain disadvantages. The most notable of these is a problem with reproduction in males, caused by an excessively elongated gonopodium. Although recommendations for gonopodium trimming are sometimes found on various specialized forums and websites, such "surgical intervention" is not suitable for hobbyists and beginner aquarists and should not even be considered. To obtain healthy offspring, it is often resorted to crossing a female Lyretail Swordtail with a male of another breed, for example, a Red Swordtail. The "long fin" gene is dominant, ensuring its manifestation in a significant portion of the fry.

The species has a strong immune system provided that water purity is maintained and stress is absent. Common problems include infections caused by protozoa or bacteria, often arising from poor water quality or overcrowding. They are sensitive to sudden changes in environmental parameters. For disease prevention, regular water changes (about 25–30% weekly) and the use of quality filtration are recommended. If signs of illness appear (clamped fins, film, refusal to eat), water parameters must be checked.

When purchasing, choose active fish with clean fins and scales, free of any signs of film, sores, or spots. It is important to pay attention to the condition of the caudal fin's "fork": it should be symmetrical, without signs of rot or mechanical damage. Avoid individuals that stay at the bottom, look emaciated, or have an abnormally swollen abdomen. It is advisable to acquire young fish, as they adapt more easily to new aquarium conditions.