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Maximum size : 10 cm

Swordtail - Xiphophorus helleri : Complete Fish Profile & Care Guide

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Swordtails (Xiphophorus helleri) are a beloved aquarium fish and a popular choice for many hobbyists. Due to their hardiness and adaptability to various water conditions, the Green Swordtail has been bred into several hybrid forms, making them an excellent choice for beginners in the hobby. These active and peaceful fish work well in community tanks with other small, peaceful fish or in a species-only tank. However, avoiding keeping them with larger, more boisterous fish is essential, as Swordtails can become nervous and hide among the plants and decorations. While they live in groups, Swordtails are not shoaling fish and are best kept in groups of five or more, with more females than males, to avoid aggression between males. The wild form of Swordtails is olive green with a red or brown lateral stripe and speckles on the dorsal and occasionally caudal fins. However, they are best known for their unique and attractive tail, which is yellow and edged in black below, a feature exclusive to males. Thanks to captive breeding, many colour varieties and patterns are available in the aquarium hobby, including black, red, and more, but they all originate from the wild green form. Overall, Swordtails are a fascinating and beautiful addition to any aquarium.

Swordtail Photos

Sexual Dimorphism

Determining the gender of Swordtails is a straightforward process. Males can be distinguished by the presence of a Gonopodium, which is a modified anal fin used to impregnate females during breeding. Furthermore, the male's caudal fin extends from its lower half, sometimes reaching up to half the length of its entire body. Conversely, the female's caudal fin does not exhibit such protrusion. Additionally, females are generally more prominent than their male counterparts.

Quick Facts

Scientific NameXiphophorus helleri
Year Described1848
Other NamesRed, Green, Tuxedo, Koi, Lyretail, Black, Hi-fin, Neon
OriginsMexico Guatemala Honduras
Max Size10 cm
Aquarium LevelMiddle - Top
DifficultyBeginner - Intermediate
Best kept asGroups 5+
Lifespan3 - 5 years

Water Parameters

Water TypeFreshwater
PH7.0 - 8.5
GH12 - 30
65 - 82
18.3 - 27.8

Natural habitat

Originating from the clear and fast-flowing streams and rivers of Veracruz, Mexico, Guatemala, and northwestern Honduras in North and Central America, Swordtails are a fascinating species. These versatile fish can thrive in various aquatic environments, from pools and canals to warm springs. While they enjoy grazing on vegetation, they do not require a densely planted tank. Consequently, these fish are rarely found in woody areas or those with high quantities of leaf litter, preferring clearer substrates that are sandy, rocky, and light. Even with mulm and debris, Swordtails can still thrive as long as the waters are fast-flowing. Overall, Swordtails are a resilient and adaptable species that can add both beauty and character to any aquarium.

How to breed the Swordtail

Breeding Swordtails is a straightforward process, making them an excellent choice for amateur aquarists. When the tank conditions are appropriate and contain both males and females, reproduction occurs naturally without intervention. In mixed-gender tanks, all-female groups are often already pregnant upon arrival, forming a breeding population once the fry reaches sexual maturity around three months of age. Later pregnancy stages are easily identifiable as a dark gravid spot develops near the anal fin. To prevent male harassment of individual females, a ratio of one male to three or four females is recommended. In addition, the presence of plants and other structures in the aquarium provides newborn fry with shelter and a safe haven from other aquarium inhabitants that may prey on them. Alternatively, setting up a separate grow-out tank can increase fry survival. As soon as they are born, baby Swordtails search for food. Newly-hatched brine shrimp and finely crumbled flakes are excellent first foods until they are big enough to consume the same food as the adults. Swordtail fry growth is relatively slow, but frequent water changes and a plentiful meat supply can promote faster growth. Overall, Swordtails are an excellent breeding option for aquarists, offering an easy and rewarding experience.

Diet & feeding

Swordtails are not picky eaters and will consume almost anything, including algae and other vegetation, in their natural habitat. However, in captivity, it is crucial to provide them with high-quality dried foods such as flakes, granules, pellets, and algae wafers, as well as excellent quality frozen and live foods like brine shrimp, mosquito larvae, fruit flies, bloodworm, and daphnia. To ensure their nutritional needs are met, providing them with a balanced diet consisting of an ideal mix of protein and vegetation is essential. In addition, feeding them two to three times daily is recommended, providing only the amount they can consume within a few minutes, and removing any leftover food to prevent water pollution. By establishing a feeding routine, your Swordtails will quickly learn when to expect food and become much more active during feeding times. Overall, maintaining a balanced and varied diet is crucial to ensuring the health and vitality of these remarkable fish.

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