Hyphessobrycon jackrobertsi: A Comprehensive Guide to Jack Roberts’ Tetra

Hyphessobrycon jackrobertsi: A Comprehensive Guide to Jack Roberts' Tetra

Hyphessobrycon jackrobertsi, commonly known as Jack Roberts’ tetra, is a small and beautiful freshwater fish that belongs to the Characidae family. It was first described by N. K. Lujan, M. Hidalgo, and D. C. Werneke in 2013. The species is endemic to the Madre de Dios drainage in the Amazon Basin, specifically found in the upper Tambopata River in Peru.

There are no known synonyms for Hyphessobrycon jackrobertsi.

Common Names:
Hyphessobrycon jackrobertsi is commonly known as Jack Roberts’ Tetra.

The species is named after Jack Roberts, an ichthyologist and president of the Colorado Aquarium Society, who made significant contributions to the aquarium hobby and the field of ichthyology.

Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Characiformes
Family: Characidae
Genus: Hyphessobrycon
Species: Hyphessobrycon jackrobertsi

Hyphessobrycon jackrobertsi is native to the Madre de Dios drainage in the Amazon Basin, specifically found in the upper Tambopata River in Peru. It is endemic to this region and is not found elsewhere in the world.

These tetras inhabit slow-moving or standing waters in the upper Tambopata River and its tributaries. The natural habitat consists of blackwater environments with dense vegetation, submerged roots, fallen leaves, and branches. The water is typically acidic and soft, mimicking the conditions found in the Amazon rainforest.

Maximum Standard Length:
The maximum standard length of male Hyphessobrycon jackrobertsi is around 3 centimeters (1.2 inches), while females can reach up to 2.5 centimeters (1 inch).

Recommended Aquarium Size:
A small group of Hyphessobrycon jackrobertsi can be comfortably housed in an aquarium with a minimum capacity of 20 liters (5 gallons). However, providing a larger tank, such as a 60-liter (15-gallon) aquarium or more, will allow for better swimming space and a more stable environment.

Maintenance Conditions:
Maintaining Hyphessobrycon jackrobertsi in captivity requires attention to certain conditions. It is recommended to have a well-established aquarium with live plants, driftwood, and leaf litter to mimic their natural habitat. The tank should provide areas for swimming as well as hiding spots. A dimly lit aquarium with floating plants can help replicate the subdued lighting conditions they prefer.

Water Conditions:
These tetras prefer soft and acidic water conditions. The ideal temperature range for Hyphessobrycon jackrobertsi is between 24-28°C (75-82°F). The pH level should be slightly acidic, ideally around 6.0-6.5, and the water hardness should be kept low, ranging from 2-6 dGH.

Jack Roberts’ tetra
This captivating image showcases the vibrant beauty of Hyphessobrycon jackrobertsi, commonly known as Jack Roberts’ tetra. The fish, brilliantly colored with shades of iridescent red, shimmering silver, and hints of yellow, is the centerpiece of the image. Its slender body and flowing fins are elegantly displayed as it gracefully swims through the water. The intricate details of its scales and the intricate patterning of its fins are truly mesmerizing. The contrasting colors create a stunning visual display that captures the eye. This image highlights the unique and enchanting allure of Hyphessobrycon jackrobertsi, a true gem in the aquatic world.

Recommended Diet:
In the wild, Hyphessobrycon jackrobertsi feeds on small invertebrates, insects, and plant matter. In captivity, they readily accept high-quality flake or pellet foods designed for tropical fish. Supplementing their diet with live or frozen foods such as brine shrimp, bloodworms, daphnia, and small insects will provide them with a varied and nutritious diet.

Behaviour and Compatibility:
Jack Roberts’ tetras are generally peaceful and can be kept in community aquariums with other small, non-aggressive fish. They should be kept in small groups of at least six individuals to minimize stress and encourage natural behavior.

While peaceful, they may display minor territorial behaviors among themselves, especially during breeding. It is important to provide ample hiding places and visual barriers in the aquarium to reduce any potential aggression. They are active swimmers and appreciate open spaces for swimming.

Sexual Dimorphism:
Sexual dimorphism is present in Hyphessobrycon jackrobertsi. Males tend to have more vibrant colors, especially during breeding, with intense red or orange fins and a darker overall body coloration. Females, on the other hand, have a slightly duller appearance and lack the intense coloration seen in males.

Breeding Conditions:
To encourage breeding, a separate breeding tank with specific conditions can be set up. The tank should be dimly lit and filled with soft, acidic water. Provide fine-leaved plants or a mesh spawning mop where the female can deposit her eggs. It is advisable to condition the breeding pair with live and frozen foods to enhance their reproductive readiness.

Once the eggs are laid, the parents should be removed from the breeding tank to prevent them from eating the eggs. The eggs typically hatch within 24-48 hours, and the fry will become free-swimming after a few more days. At this point, they can be fed with infusoria or commercially available fry foods until they are large enough to consume finely crushed flakes or brine shrimp nauplii.

Other Useful Information:

  • Hyphessobrycon jackrobertsi is a peaceful and active species that can add color and movement to a well-maintained community aquarium.
  • They are relatively small, making them suitable for smaller aquariums and nano tanks.
  • Regular water changes and proper filtration are crucial for maintaining their health and well-being.
  • Adding dried Indian almond leaves or other botanicals to the aquarium can help simulate their natural habitat and create a beneficial environment.
  • Hyphessobrycon jackrobertsi is a relatively new species in the aquarium trade, and availability may vary. It is important to purchase from reputable sources and ensure the fish are healthy and properly cared for.
  • The species has not been assessed for its conservation status by the IUCN, but as with all species, it is important to practice responsible aquarium keeping and avoid purchasing wild-caught specimens if possible.