False black tetra - Gymnocorymbus thayeri

Scientific name: Gymnocorymbus thayeri

Common name: False black tetra

Family: Characidae

Usual size in fish tanks: 4 - 5 cm (1.57 - 1.97 inch)

014

Recommended pH range for the species: 6.3 - 7.4

Recommended water hardness (dGH): 5 - 22°N (89.29 - 392.86ppm)

0°C 32°F30°C 86°F

Recommended temperature: 22 - 27 °C (71.6 - 80.6°F)

The way how these fish reproduce: Spawning

Where the species comes from: South America

Temperament to its own species: peaceful

Temperament toward other fish species: peaceful

Usual place in the tank: Top levels

Introduction

Gymnocorymbus thayeri, commonly known as the False Black Tetra, is a peaceful and adaptable species native to the waterways of Colombia, Brazil, and Bolivia in South America. Their calm temperament, manageable size, and schooling behavior make them an excellent choice for community aquariums, particularly those with soft, planted setups.

Food and Feeding

False Black Tetras are omnivorous and will accept a variety of foods. Offer a high-quality flake or small pellet food as their staple diet. Supplement this with live or frozen treats such as brine shrimp, daphnia, or bloodworms to enhance their coloration and health. Feeding small portions multiple times a day can help replicate their natural grazing habits and keep them active and healthy.

Habitat and Tank Requirements

To replicate their natural habitat, set up a densely planted tank with soft, slightly acidic water. Include hiding spots using driftwood, rocks, and broad-leaved plants such as Amazon Sword (Echinodorus bleheri) and Java Fern (Microsorum pteropus). Maintain water parameters with a pH of 6.3-7.4, hardness of 5-22°N (89.29-392.86 ppm), and a temperature range of 22-27°C (71.6-80.6°F). Regular water changes and good filtration are essential to maintain high water quality.

Sexing

Males and females look similar, but females tend to have a rounder, plumper appearance, especially during the breeding season. Males may be slightly slimmer and more active in courtship displays.

Breeding

Breeding Gymnocorymbus thayeri is achievable with proper preparation. Set up a separate breeding tank with soft, acidic water and dense plant cover to provide egg-laying sites. Condition the breeding pair with live or frozen foods for two weeks before introducing them to the breeding setup. During spawning, the female scatters eggs around the tank, which should be protected by removing the parents immediately after spawning. Eggs typically hatch within 24-36 hours, and fry become free-swimming shortly after. Feed the fry with Infusoria or similar fine foods, transitioning to newly hatched brine shrimp as they grow.

Lifespan

The expected lifespan of False Black Tetras is 3-5 years when provided with proper care and a stable environment.

Behavior and Compatibility

False Black Tetras are peaceful schooling fish that thrive in groups of at least six. Their calm nature makes them excellent additions to community tanks with other non-aggressive species. Suitable tank mates include Neon Tetras (Paracheirodon innesi), Harlequin Rasboras (Trigonostigma heteromorpha), Dwarf Gouramis (Colisa lalia), Ember Tetras (Hyphessobrycon amandae), Rummy-Nose Tetras (Hemigrammus bleheri), and Otocinclus Catfish (Otocinclus affinis). Their peaceful demeanor also makes them compatible with Corydoras Catfish and Kuhli Loaches (Pangio kuhlii).

It is important to avoid keeping False Black Tetras with larger or aggressive species, as they may become stressed or outcompeted for food. Acaras and other cichlids are not suitable tankmates, as their size and temperament can intimidate or harm the tetras. False Black Tetras are active swimmers and prefer the top levels of the tank, adding dynamic movement to any aquarium. Always provide plenty of swimming space and a well-planted environment to keep them comfortable.

Short Description

Gymnocorymbus thayeri, or False Black Tetra, is a peaceful, schooling fish that thrives in planted tanks with soft, acidic water. Their calm temperament and compatibility with other peaceful species make them a great choice for community setups. Provide hiding places and maintain high water quality to keep them thriving.