The Harlequin Rasbora (Trigonostigma heteromorpha) is a beautiful and popular freshwater fish species native to Southeast Asia, particularly found in the slow-moving streams and forested areas of Malaysia, Singapore, and Thailand. Here's some information about them:
Appearance: Harlequin Rasboras are small, slender fish with a streamlined body and striking coloration. They have a metallic silver body with iridescent scales and a distinctive triangular black patch that extends from the midsection to the base of their tail. Above this patch, they exhibit a vibrant orange to red coloration, which intensifies during periods of activity or breeding.
Behavior: Harlequin Rasboras are peaceful and sociable fish, making them ideal for community aquariums. They are active swimmers and prefer to be kept in groups of at least six individuals or more, which helps reduce stress and encourages natural shoaling behavior. They are not aggressive and generally get along well with other peaceful fish species.
Tank Requirements: They thrive in well-planted aquariums with plenty of swimming space and subdued lighting. A tank size of at least 10 gallons (38 liters) is suitable for a small group of Harlequin Rasboras, although larger tanks are recommended for larger groups. They prefer slightly acidic to neutral water with a pH range of 6.0-7.0 and a temperature range of 72-78°F (22-26°C).
Diet: Harlequin Rasboras are omnivores and will accept a variety of foods. They have a small mouth and prefer smaller-sized foods such as micro pellets, flakes, and frozen or live foods like brine shrimp, bloodworms, and daphnia. They also enjoy nibbling on algae and may benefit from occasional vegetable matter in their diet.
Compatibility: Harlequin Rasboras are peaceful and can be kept with a wide range of tankmates, including other small, non-aggressive fish species that share similar water parameters. Suitable tankmates include other rasbora species, tetras, danios, peaceful barbs, dwarf gouramis, and small catfish species. Avoid keeping them with larger or more aggressive fish that may intimidate or outcompete them for food.
Breeding: Harlequin Rasboras are egg scatterers and will spawn in well-planted aquariums under the right conditions. Breeding setups may require separate spawning tanks with soft, acidic water, and fine-leaved plants such as java moss or spawning mops for egg deposition. Once spawning occurs, remove the adult fish to prevent them from consuming the eggs.
Overall, Harlequin Rasboras are a popular choice among aquarists due to their stunning appearance, peaceful nature, and ease of care. With proper tank conditions and suitable tankmates, they can thrive and bring color and activity to any community aquarium.
