Purple Harlequin Rasbora (Trigonostigma heteromorpha)

Purple Harlequin Rasbora (Trigonostigma heteromorpha) is a selectively bred variant of the classic Harlequin Rasbora, known for its darker, more dramatic coloration and peaceful nature. 

Description

• Coloration: This variant features a deep purple to black body tone, especially as it matures, with the signature black triangular patch near the tail. The darker hues are a result of selective breeding and are more pronounced than in wild-type Harlequins 
• Size: Typically reaches about 1 inch (2.5 cm) in length 
• Behavior: Peaceful, schooling fish that thrive in groups of 10 or more. They exhibit synchronized swimming and are ideal for planted or nano tanks 

Tank Setup

• Tank Size: Minimum 10 gallons for a small school 
• Water Parameters:
  • Temperature: 76–80°F (24–27°C)
  • pH: 6.8–7.8
  • Ammonia/Nitrite: 0 ppm
  • Nitrate: <30 ppm 
• Aquascape:
  • Mimic their natural habitat: slow-moving streams with sandy substrate, tannin-stained water, and dense aquatic vegetation 
  • Use driftwood and leaf litter to enhance comfort and coloration.

Diet

• Type: Omnivore and micropredator
• Feeding:
  • Accepts flakes, micro pellets, and frozen foods.
  • Enjoys live foods like daphnia, brine shrimp, and mosquito larvae 

Breeding

• Method: Egg layers
• Spawning Behavior:
  • Females lay eggs on the underside of broad leaves.
  • Males fertilize externally during the process 
• Tips:
  • Use soft, acidic water and dim lighting.
  • Remove adults post-spawning to protect eggs.
  • Eggs hatch in ~18 hours at 28°C; fry become free-swimming in 1–2 days 

Tankmates

• Compatibility: Peaceful with similarly sized fish.
• Ideal Companions:
  • Neon tetras, guppies, corydoras, dwarf gouramis, cherry barbs, and other small community fish