Hi-Fin Tetra Care Guide - Aquarium Setup, Diet & Breeding

Hi-Fin Tetras are a striking variety of the familiar X-ray Tetra, distinguished by their unusually tall dorsal fin. Their translucent, silvery body allows the skeleton and internal organs to be faintly visible, while the dorsal, anal and pelvic fins typically carry bold black, yellow and white markings. The high dorsal fin gives this small schooling fish a particularly elegant profile.

Hi-Fin Tetras are the selectively bred high-fin form of the X-ray Tetra, Pristella maxillaris. The species is native to northern and eastern South America, including Brazil, Venezuela and the Guianas, where it inhabits tributaries, flooded forest margins and coastal freshwater environments connected with the Amazon and Orinoco regions.

A group of Hi-Fin Tetras should have an aquarium of at least 60 litres, with a footprint around 60 by 30 cm and enough open swimming space for the shoal. Use gentle filtration and provide a planted layout with some floating cover, shaded areas and driftwood or other subdued decor, while leaving the front and centre relatively open. A dark, fine-grained substrate can enhance their colours, although any smooth aquarium-safe substrate is suitable. Secure the aquarium cover because these active fish may jump.

Up to 5 cm (2 inches) in total length. Females are usually slightly larger and deeper-bodied than males, while males tend to be slimmer.

Hi-Fin Tetras are omnivores and readily accept quality small flakes, micro-pellets and granules. Their diet should be varied with suitably sized frozen or live foods such as brine shrimp, daphnia, mosquito larvae and bloodworm, offered in moderation. Small portions fed once or twice daily are preferable to amounts that sink uneaten, and the food should be fine enough for their small mouths.

Hi-Fin Tetras are peaceful community fish and can be kept with similarly sized, non-aggressive species such as other small tetras, rasboras, danios, peaceful barbs, Corydoras, kuhli loaches and small livebearers. They should not be housed with large predatory fish, fin-nippers or boisterous species that may damage their tall fins or outcompete them for food. Keeping them in a proper group helps them remain confident and reduces the chance of fin-focused behaviour within the shoal.

Hi-Fin Tetras are egg scatterers that can be bred in a separate, dimly lit breeding aquarium with soft, slightly acidic water and fine-leaved plants or spawning mops. Condition males and females with small amounts of nutritious live or frozen food, then introduce them when the females are full of eggs. Spawning usually takes place among the plants, after which the adults should be removed because they may eat the eggs. The eggs hatch in around 24 hours, and the tiny fry can be raised on infusoria or commercially prepared fry food before progressing to baby brine shrimp.

Females are generally fuller through the belly, especially when carrying eggs, and may be slightly longer than males. Males are typically more slender, with a narrower body profile and a more streamlined appearance.