Harlequin Rasbora - Trigonostigma heteromorpha : Complete Fish Profile & Care Guide
Table of contents
Introduction
Harlequin Rasboras (Trigonostigma heteromorpha) are an exquisite choice for aquarists seeking captivating visuals and lively aquatic companions. Renowned for their peaceful disposition and robust nature, these fish seamlessly integrate into both community aquariums and nano aquascapes. In captivity, Harlequin Rasboras demonstrate a propensity for shoaling, flourishing most optimally when maintained in groups consisting of eight individuals or more. The observation of their synchronized movements and harmonious group dynamics within an aquarium environment not only enhances its aesthetic appeal but also offers valuable insights into their innate behavioural patterns.
These fish demonstrate compatibility with a variety of small temperate species, including Tetras, Bettas, Dwarf Barbs, and Gouramis. However, it is advisable to avoid housing them with larger or more aggressive counterparts. To establish an optimal aquarium environment, replicate their natural habitat by maintaining soft, acidic water conditions and incorporating ample vegetation, driftwood, and leaf litter. Implementing dim lighting and integrating floating plants will contribute to a natural ambience, fostering their well-being and comfort.
Harlequin Rasboras have a copper-red metallic body with a signature black triangular wedge and red-lined fins. Captive-bred black and gold strains are also available, adding to the variety of this already captivating fish. Feeding Harlequin Rasboras is relatively easy; they are omnivores and will readily accept dried foods like flakes and pellets, supplemented with small live and frozen foods such as daphnia, brine shrimp, and bloodworms. Overall, Harlequin Rasboras are a beautiful, peaceful, and fascinating addition to any aquarium, providing a lively display and adding a touch of elegance to any aquascape.
Harlequin Rasbora Photos
Sexual Dimorphism
The process of identifying the gender of Harlequin Rasboras is relatively straightforward. Males tend to have more striking colours and a slimmer physique than their female counterparts. In addition, the triangular patch on the male's body is typically rounder and more elongated than in females. On the other hand, females tend to have a plumper body shape and less distinct colouration compared to males.
Quick Facts
| Scientific Name | Trigonostigma heteromorpha |
|---|---|
| Year Described | 1904 |
| Other Names | Red Rasbora, Harlequin Fish, Red Razor |
| Kingdom | Animalia |
| Classification | Actinopterygii |
| Order | Cypriniformes |
| Family | Cyprinidae |
| Genus | Trigonostigma |
| Origins | Thailand , Malaysia , Singapore , Indonesia |
| Max Size | 5 cm |
| Temperament | Peaceful |
| Aquarium Level | Middle - Top |
| Difficulty | Beginner - Intermediate |
| Shoaling | Yes |
| Best kept as | Groups 6+ |
| Diet & Feeding | Omnivore |
| Reproduction | Egg Depositor |
| Average Lifespan | Up to 8 Years |
Water Parameters
| Water Type | Freshwater |
|---|---|
| pH | 6 - 7 |
| GH | 2 - 15 |
| TDS | 18 - 215 |
| ℉ | 72 - 82 |
|---|---|
| ℃ | 22 - 28 |
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Featured Species
Natural Habitat
Harlequin Rasboras hail from the regions of Malaysia, Sumatra, and southern Thailand in Southeast Asia. They also inhabit the Nee Soon Swamp in Singapore, favouring slow-moving blackwaters found in streams, rivers, and swamp forests. Typically dwelling in habitats characterized by slightly acidic to neutral and soft water conditions, these Rasboras thrive in shaded environments beneath the forest canopy.
The presence of fallen leaves, twigs, and branches covering the substrates provides ample feeding opportunities, shelter, resting spots, and hiding places for these captivating fish. Incorporating Harlequin Rasboras into your aquarium not only showcases their distinctive beauty but also contributes to their conservation endeavours.
Breeding
Breeding Harlequin Rasboras can be a challenging yet rewarding experience for aquarists. To successfully breed these fish, it is recommended to set up a separate breeding tank with soft, shallow water and peat filtration. Broad-leaved plants should also be added to provide a suitable spawning site. Spawning usually occurs in the morning, triggered by the first rays of sunlight. Females can lay up to 250 eggs on the underside of leaves, with males fertilizing them using a shaking motion.
The process may last up to two hours, with the female laying six to twelve eggs at a time. After the eggs are laid, it is crucial to remove the parents from the breeding tank to prevent them from eating the eggs. The tank should be covered to prevent light exposure and fungus growth. Hatching occurs around 24 hours after laying, and the fry will become free-swimming 72 hours later.
These tiny fry require small-grade foods, starting with infusoria and gradually moving on to more significant foods as they grow. Frequent partial water changes are necessary as the fry is highly sensitive to changes. Overall, breeding Harlequin Rasboras requires careful attention to water quality and the right environment for the fish to spawn.
Diet & Feeding
Harlequin Rasboras exhibit an omnivorous feeding behaviour, readily accepting a diverse array of food sources suitable for their small mouths. At feeding times, these fish demonstrate heightened activity levels, eagerly consuming high-quality dried foods like flakes or pellets. To maintain optimal health and nutrition, it is advisable to augment their diet with small live and frozen offerings such as daphnia, brine shrimp, and bloodworms.
Frequently asked questions
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