Maximum size : 2 cm

Fire Ant Tetra - Hyphessobrycon myrmex : Complete Fish Profile & Care Guide

Table of contents


The Fire Ant Tetra (Hemigrammus sp. "Fire Ant") is an intriguing and relatively new addition to the aquarium hobby, having been discovered as recently as 2017. Originating from South America, these characins showcase a captivating feature known as sexual dichromatism, where males and females exhibit distinct colouration differences.

While Fire Ant Tetras can coexist in a community aquarium, it is crucial to consider their small size and timid nature when selecting tankmates. Opting for other small and peaceful characins will ensure a harmonious environment. Additionally, given their natural inclination to school, keeping these Tetras in groups of 10 or more individuals is recommended. Doing so not only promotes their well-being but also enhances the visual allure of your aquarium.

Creating a suitable habitat for Fire Ant Tetras involves carefully considering the aquarium setup. Whether opting for a heavily planted nano tank or a larger South American river biotope, a sandy substrate, dense vegetation, strategically placed driftwood branches, and leaf litter are essential. These elements mimic their natural environment and provide shaded areas where these Tetras can find solace. Additionally, incorporating floating plants helps diffuse the light, creating a more tranquil setting for the fish.

The males of the Fire Ant Tetra boast a beautiful reddish-orange body colouration that gradually transitions to a lighter shade towards the dorsal fin. Their heads are predominantly red, adorned with silver pigmentation and an orange jaw. The eyes of the males exhibit an intense orange hue on the dorsal portion, while the anterior margin appears light orange, and the posterior margin displays a silvery shade. Their fins, with the exception of the hyaline dorsal fin showcasing a few orange specs near the base, showcase a vibrant range of orange to red tones.

In contrast, the females and juvenile Fire Ant Tetras display a more subdued palette, with pale yellow bodies and heads. Their jaws exhibit a light yellow colouration, while their eyes shimmer with silvery tones and a yellowy-orange pigmentation. The adipose and dorsal fins take on a light yellow shade, while the remaining fins appear pale orange. In addition, both males and females possess a distinct dark lateral stripe that runs along their sides, extending above their caudal fins.

The mesmerizing colouration and distinctive features of the Fire Ant Tetra make them a captivating addition to any aquarium, contributing to a visually striking and engaging aquatic display.

Fire Ant Tetra Photos

Sexual Dimorphism

Distinguishing between male and female Fire Ant Tetras is a straightforward task. Adult males exhibit distinct characteristics that set them apart from females. Typically, males display a darker and more vibrant colouration compared to females. Additionally, their anal fin appears straight to slightly concave in shape. On the other hand, the anal fin of adult females is consistently concave in appearance. Females, in general, tend to be lighter in colouration and lack the intense vibrancy observed in males. Observing these visual cues makes it possible to discern the gender of Fire Ant Tetras with relative ease.

Featured Male
Featured Female
Female Male

Quick Facts

Scientific NameHyphessobrycon myrmex
Year Described2017
Other NamesAnt Tetra
Max Size2 cm
Aquarium LevelMiddle - Top
DifficultyBeginner - Intermediate
Best kept asGroups 8+
Diet & FeedingOmnivore
LifespanUp to 5 Years

Water Parameters

Water TypeFreshwater
pH 6.0 - 7.5
GH 5 - 15
TDS 36 - 179
Ideal Temperature
72 - 82
22 - 27

Natural Habitat

Fire Ant Tetras are native to the captivating waters of the Formiga River, an enchanting tributary of the Juruena River, nestled within the majestic landscapes of Serra dos Parecis and the upper Rio Tapajós basin in Brazil, South America. These remarkable tetras thrive in the energetic embrace of rapidly flowing, crystal-clear waters, where the substrate is adorned with a picturesque tapestry of sand, stones, and an ample presence of natural vegetal debris. Their natural habitat offers a captivating glimpse into the harmonious coexistence of aquatic life amidst the pristine beauty of Brazilian ecosystems.


Regrettably, there is limited information available regarding the breeding habits of Fire Ant Tetras; however, based on the behaviour of other Hyphessobrycon species, it is likely that these Tetras follow a similar breeding pattern.

Fire Ant Tetras are egg-scattering free spawners that do not exhibit parental care. In a well-conditioned community tank, adult fish may naturally spawn, leading to the emergence of a small number of fry without human intervention. However, for those seeking to raise a significant number of fry, a separate breeding tank is recommended.

The breeding tank should be dimly lit, and the base should be equipped with mesh or fine-leaved plants like java moss to provide a safe haven for the eggs, protecting them from the adults. Water conditions in the breeding tank should be soft, slightly acidic to neutral, with a temperature range of 79 to 82 degrees Fahrenheit (26 to 28 degrees Celsius). To ensure gentle filtration, an air-driven sponge filter is preferable, and dedicated lighting is not necessary as the eggs and fry can be sensitive to light.

Fire Ant Tetras can be bred in pairs or small groups; however, removing the adult fish after spawning is crucial to prevent them from consuming the eggs. Once the eggs have hatched, the fry will initially rely on their yolk sacs for sustenance. As the fry becomes free-swimming, it is recommended to provide them with microscopic foods such as infusoria and Paramecium. Subsequently, the diet can be supplemented with microworms or baby brine shrimp as the fry develops.

While breeding Fire Ant Tetras may present some challenges due to the limited information available, careful attention to water conditions, lighting, and food provisioning can increase the chances of successful breeding and the subsequent growth of the fry.

Diet & feeding

Fire Ant Tetras exhibit a versatile feeding behaviour in an aquarium setting and are not overly selective. To ensure their optimal nutrition, it is advisable to provide them with high-quality dried food options like flakes or granules as the mainstay of their diet. In addition, supplementing their meals with occasional servings of live, frozen, or freeze-dried delicacies such as brine shrimp, daphnia, mosquito larvae, and bloodworm will add variety and further enhance their overall health and colouration. Offering a diverse range of food options is crucial in maintaining the vitality and vibrant hues of these fascinating fish.

Other Tetras of interest