Xiphophorus pigmaeus 2 cm | Pygmy Swordtail

Overview

Xiphophorus pigmaeus, commonly known as the Pygmy Swordtail, is a charming dwarf livebearer that brings colour, movement and constant activity to the aquarium. Reaching only around 3.5–4 cm as adults, this species is one of the smallest members of the swordtail group and is a superb choice for aquarists looking for a peaceful, plant-friendly fish with an engaging personality.

Offered here at approximately 2 cm, these young fish are ideal for hobbyists who want to grow them on in a well-established aquarium. Males are typically slimmer and more colourful, while females are slightly larger and fuller-bodied. Like other livebearers, they are hardy, adaptable and rewarding to keep, especially in a planted setup where they can display natural behaviour and feel secure.

At Tropical Fish Co, we supply healthy livestock with a live arrival guarantee and fast UK delivery, so your fish arrive in the best possible condition for acclimation and long-term success.

Care at a Glance

Origin & Natural Habitat

Xiphophorus pigmaeus is native to north-eastern Mexico, where it inhabits slow-moving freshwater systems such as streams, ditches, canals and shallow vegetated waters. In the wild, it is often found among dense aquatic plants and marginal growth, using cover to avoid predators while foraging for tiny invertebrates, algae and plant matter.

This natural preference for sheltered, planted environments translates beautifully to the aquarium. A tank with live plants, gentle filtration and open swimming space will help these fish feel at home and encourage natural schooling and feeding behaviour. Their small size and calm nature make them especially suitable for aquascaped community tanks.

Tank Setup & Water Parameters

Pygmy Swordtails do best in a mature aquarium with stable water conditions. Although they are relatively hardy, they appreciate clean water and regular maintenance. A 60-litre tank is a sensible minimum for a small group, with more space always beneficial if you plan to keep them with other peaceful species.

Provide a planted layout with fine-leaved stems, floating plants and areas of cover. This helps females and juveniles feel secure and gives males room to display. A dark substrate can enhance their colours, while moderate lighting will support plant growth without making the fish feel exposed.

Filtration should be efficient but not overly strong, as these fish come from calmer waters and do best with a gentle current. Regular partial water changes are important to maintain excellent water quality. Aim for stable parameters rather than chasing extremes, as consistency is key to long-term health.

Recommended conditions:

• Temperature: 22–28°C
• pH: 6.8–8.0
• Hardness: Soft to moderately hard water is acceptable, with a preference for neutral to slightly alkaline conditions

As with all livebearers, avoid sudden changes in temperature or chemistry. Acclimate slowly on arrival and allow the fish to settle before introducing them to a busy community.

Feeding Guide

Xiphophorus pigmaeus is an omnivore with a strong appetite for a varied diet. In the aquarium, it will readily accept high-quality micro pellets, crushed flake, and small frozen or live foods such as daphnia, baby brine shrimp and cyclops. A varied feeding routine helps maintain colour, condition and breeding readiness.

Feed small amounts once or twice daily, only as much as the fish can consume in a couple of minutes. Because these fish are tiny, food size matters: choose finely crushed foods or specialist micro feeds to ensure all individuals can eat comfortably. Occasional vegetable-based foods, spirulina flakes or blanched greens can also be beneficial.

Overfeeding should be avoided, as livebearers can be prone to digestive issues if given rich foods in excess. A balanced diet with regular water changes will keep them in top condition.

Tank Mates / Compatibility

Pygmy Swordtails are peaceful and sociable, making them excellent candidates for calm community aquariums. They are best kept with other non-aggressive species that will not outcompete them for food or nip at their fins. Small rasboras, peaceful tetras, dwarf corydoras, otocinclus and gentle shrimp are all good possibilities in suitably sized tanks.

Because of their small size, avoid housing them with large, boisterous or predatory fish. Fin-nippers and highly territorial species can stress them, while very fast feeders may leave them undernourished. If keeping males and females together, be aware that livebearers can breed readily in the right conditions, so provide planting and cover for fry if you wish to raise young.

For best results, keep them in a small group with a balanced sex ratio and plenty of planting. This helps reduce stress and encourages natural behaviour. They are not ideal for very coldwater or highly acidic specialist setups.

Why Buy from Tropical Fish Co

At Tropical Fish Co, we focus on supplying healthy, well-conditioned aquatic livestock with careful packing and reliable service. Our fast UK delivery helps reduce transit stress, and our live arrival guarantee gives you added confidence when ordering online.

We recommend this species for aquarists who want a peaceful, attractive livebearer that stays small and suits planted aquariums. Whether you are building a nano community or adding interest to an established aquascape, Xiphophorus pigmaeus offers colour, activity and easy-going charm in a compact package.

Choose Tropical Fish Co for quality fish, helpful care guidance and dependable delivery from a specialist UK aquatic retailer.