Product Details

Serpae Tetra Longfin – Megalamphodus eques

The Serpae Tetra Longfin is a bright red, active tetra selected for longer flowing fins than the standard Serpae Tetra. Long known in the aquarium trade as Hyphessobrycon eques and sometimes linked with the older name Hyphessobrycon callistus, this fish is best kept as a lively shoaling species rather than a gentle nano tetra. Its colour and movement make it a striking choice for planted community aquariums, but the longfin strain needs careful tank mate selection because Serpae Tetras can be fin-nippy if kept in small groups.

Key Identification:

Common Name: Serpae Tetra Longfin
Other Names: Longfin Serpae Tetra, Long Fin Serpae, Red Minor Tetra, Jewel Tetra, Blood Tetra, Serpa Tetra
Scientific Name: Megalamphodus eques
Older / Trade Names: Hyphessobrycon eques, Hyphessobrycon callistus, Hyphessobrycon serpae
Fish Type: Tetra / Characin
Water Type: Freshwater

Natural Range & Habitat:

Wild Serpae Tetras are South American characins associated with slow-moving and still waters, especially around areas with plant growth, stems and cover near the surface. In nature, they feed among vegetation and use shaded, structured areas for security.

The Longfin Serpae Tetra is a captive-bred ornamental strain, so its extended finnage is a selected aquarium trait rather than a wild feature. Aquarium care should still reflect the species’ preference for planted cover, stable water quality and enough open swimming space for a proper group.

Appearance & Adult Size:

Longfin Serpae Tetras have a deep tetra body with red, orange-red or amber body colour, a dark shoulder mark and contrasting black, red or pale fin markings. The longfin strain has extended dorsal, anal and caudal fins, giving a softer, more decorative shape than the standard form. Colour intensity can vary with age, mood, diet, lighting and group confidence.

Adults usually reach around 4–5 cm, with females often fuller-bodied and males usually slimmer and more intensely coloured. The extended fins may make this strain appear larger in display than the body length alone suggests.

Aquarium Suitability:

This is a good fish for a lively planted community aquarium, active tetra display or South American-style setup. It suits aquariums with plant cover, shaded areas, open swimming room and peaceful but robust tank mates. The longfin form should be kept away from species that are likely to nip its extended fins.

Serpae Tetras are not suitable for very quiet nano aquariums, male bettas, fancy guppies, long-finned gouramis, angelfish with trailing fins, delicate slow-moving fish or tiny shy species.

Recommended Aquarium Size:

A practical minimum is 90 litres for a group, with a tank length of at least 75 cm recommended. Larger aquariums of 120 litres or more are better for bigger groups, mixed communities and reducing fin-nipping behaviour.

Keep in a group of at least 8, with 10 or more preferred. Small groups are much more likely to chase, nip fins and direct attention toward tank mates.

Water Conditions:

Temperature: 22–28°C
pH: 5.5–7.5
Hardness: Soft to moderately hard
Additional Notes: Keep water clean, stable and well filtered. Serpae Tetras are adaptable once settled, but sudden changes in water chemistry should be avoided. They do not require extreme blackwater conditions, but they show well in planted aquariums with subdued lighting, darker décor and good water quality.

Temperament & Tank Mates:

Aquarium Category: Semi-Aggressive

Serpae Tetras are active shoaling fish with a reputation for fin-nipping, especially when kept in small numbers or cramped tanks. In a proper group, most chasing and displaying stays within the shoal, but they should still be matched with suitable tank mates.

Good companions include robust tetras, danios, medium rasboras, peaceful barbs, Cory-type catfish, bristlenose plecs, small peaceful cichlids with care and other active community fish that are not slow or long-finned.

Avoid male bettas, fancy guppies, fancy goldfish, long-finned gouramis, slow angelfish, delicate nano fish and very shy tank mates. Because this is the longfin strain, also avoid known fin-nippers that may damage its extended fins.

Feeding:

Serpae Tetras are easy-feeding omnivores. Offer quality flakes, small granules or micro pellets as the staple diet. Supplement with frozen or live foods such as daphnia, cyclops, brineshrimp, mosquito larvae and small bloodworm. Occasional vegetable-based or spirulina foods can be included for balance.

A varied diet helps maintain red colour, condition and natural activity. Feed small portions that are eaten quickly, as they are eager feeders and may become pushy at feeding time.

Behaviour in the Aquarium:

This species usually swims in the middle and upper areas of the aquarium, moving actively in a loose group. Males may display, chase and spar, especially in mature groups. Some in-group bickering is normal, but persistent fin damage usually points to too few fish, too little space or unsuitable tank mates.

Serpae Tetras are egg scatterers and do not provide parental care. If spawning occurs in a community aquarium, eggs and fry are usually eaten unless a separate breeding setup is used.

Care Notes:

Add Serpae Tetra Longfins only to a mature, fully cycled aquarium. Keep them in a proper group, provide open swimming space and include plants or shaded areas for security. Choose tank mates carefully, as both the Serpae Tetra’s natural nippiness and the longfin strain’s extended fins need to be considered.

Avoid overcrowding, poor water quality, very small groups and slow long-finned companions. Regular water changes and a varied diet will support colour and fin condition.

Recommended For:

Beginner to intermediate

Availability:

Common to occasional / Captive-bred longfin strain

Image Disclaimer:

All images are a visual representation of the fish you will receive, made to be as accurate as possible. Natural variation in size, red colour, fin length, fin shape, shoulder mark and markings can occur between individual fish.