GloFish® Long-Fin Tetra Care Guide - Aquarium Setup, Diet & Breeding

GloFish® Long-Fin Tetras have the deep-bodied shape associated with Black Skirt Tetras, enhanced by flowing fins and vivid fluorescent coloration. Their glowing appearance is produced by inherited fluorescent protein genes, and the fish display their colours under ordinary aquarium lighting as well as under blue or actinic illumination. They are not painted or dyed fish, and their colour is present throughout their lives.

These are active, sociable tetras that spend much of their time in the middle levels of the aquarium. In a group, they develop a lively social dynamic, with individuals displaying to one another and occasionally sparring without serious harm. Their elongated fins give them a graceful profile, although the fin edges can be vulnerable to persistent nipping.

The wild Black Skirt Tetra comes from slow-moving and still waters in tropical South America, including forested streams, tributaries and quiet areas with submerged vegetation. Its natural environment often contains shaded water, leaf litter and a mixture of open swimming spaces and cover.

GloFish® Long-Fin Tetras are captive-bred ornamental fish descended from the Black Skirt Tetra. Like the original species, they are hardy, adaptable and best appreciated as a lively group rather than as solitary display fish.

GloFish® Long-Fin Tetras are a selectively developed, fluorescent long-finned form of the Black Skirt Tetra, Gymnocorymbus ternetzi. The original species is native to freshwater habitats in the Paraguay River basin of South America, including parts of Brazil, Bolivia and Paraguay; the GloFish® coloration results from genetic modification rather than a separate wild population.

A group of GloFish® Long-Fin Tetras should be kept in an aquarium of at least 75 litres, with a footprint around 60 cm long by 30 cm wide or larger to provide uninterrupted swimming room. Use gentle filtration, open central swimming space and areas of dense planting around the sides and back. Dark substrate, driftwood and subdued shaded areas help their fluorescent colours stand out, while smooth decor and broad-leaved or silk plants reduce the risk of damage to their extended fins.

Adults reach approximately 5.5 cm (2.2 inches) in length. Females are usually slightly larger and deeper-bodied than males, while males tend to be a little slimmer; the long fins can make the overall fish appear larger.

These omnivorous tetras accept a varied diet of quality small pellets or flakes, supplemented with frozen or live foods such as brine shrimp, daphnia, mosquito larvae and bloodworms. Offer appropriately sized portions once or twice daily, with enough variety to support condition, colour and natural feeding behaviour without leaving excess food in the aquarium.

GloFish® Long-Fin Tetras generally suit peaceful community aquariums containing similarly sized, active fish such as other tetras, rasboras, peaceful barbs, livebearers, Corydoras and smaller peaceful catfish. Avoid housing them with aggressive species, very slow fish or fin-nipping tankmates, as their long fins may attract unwanted attention. They should also not be kept with large predatory fish that could swallow or harass them.

GloFish® Long-Fin Tetras are egg-scattering fish and can be bred in a separate aquarium with mature males and females. Condition the adults with plentiful live or frozen foods, then provide fine-leaved plants or a spawning mop for the adhesive eggs. Spawning usually occurs among the plants, after which the adults should be removed because they may eat the eggs. The eggs hatch in roughly 24 to 36 hours, and the tiny fry can be raised on infusoria or other suitably small first foods before moving on to baby brine shrimp.

Females are generally fuller through the body and may grow slightly larger than males. Males are typically slimmer, with a more streamlined profile, although sexing young GloFish® Long-Fin Tetras can be difficult and the long-fin form can make visual differences less obvious.