The Pastel Lily Tetra (Nematobrycon palmeri) is a captivating freshwater fish appreciated in the aquarium hobby. Its vibrant colors and distinctive finnage make it a popular choice. Often called the Emperor Tetra, this species originates from western Colombia’s river basins.
Ideal Habitat Setup
A minimum 15 to 20-gallon tank is suitable for a small group, though larger aquariums benefit larger groups. Fine gravel or sand substrate mimics their natural riverbed habitats. Dark substrate can enhance their vibrant coloration.
Densely arranged live plants, both rooted and floating, are highly beneficial. Fine-leaved plants like Java moss or Water Sprite offer excellent hiding spots. Driftwood and other ornaments provide further cover, mitigating potential male territorial displays. Lighting should be moderate to subdued, as these tetras thrive in dimly lit conditions; brighter light can make their yellow coloration more dominant.
Water Parameters and Maintenance
Maintaining appropriate water parameters is essential for Pastel Lily Tetras’ health. They prefer a stable temperature range between 23°C and 27°C (73°F to 81°F). The ideal pH level is slightly acidic to neutral, typically ranging from 5.0 to 7.5. General hardness (GH) should be kept between 1 to 10 dGH, and carbonate hardness (KH) between 4 to 8 dKH, with total dissolved solids (TDS) ideally between 50 to 300 ppm.
Proper filtration, with gentle to moderate water flow, is necessary to maintain water quality. Sponge or hang-on-back filters effectively remove waste and toxins. Regular water changes maintain a clean, healthy environment. Performing 20% to 30% water changes every one to two weeks keeps nitrate levels below 50 mg/L and ensures consistent water parameters.
Diet and Feeding
Pastel Lily Tetras are omnivorous, with a carnivorous tendency. In the wild, they consume small invertebrates, worms, crustaceans, and some plant matter. In an aquarium, high-quality flake or pellet food should be their primary staple.
For a balanced diet, supplement commercial foods regularly with live, frozen, or freeze-dried options. Choices include brine shrimp, daphnia, bloodworms, and tubifex worms, enhancing coloration and promoting breeding readiness. Feed once or twice daily, offering only what they can consume within minutes to prevent overfeeding and maintain water quality.
Tank Mates and Social Behavior
Pastel Lily Tetras are peaceful schooling fish. A minimum group of six is recommended; larger shoals (10+) encourage natural schooling and reduce stress. Their calm, non-aggressive nature makes them suitable for community aquariums.
Compatible tank mates should be of similar size and temperament, sharing similar water requirements. Avoid overly active or aggressive species, or those large enough to view tetras as prey. While male tetras may engage in sparring displays for females, these interactions are typically harmless in tanks with adequate space and decor. Good choices include:
Other small, peaceful tetras
Corydoras catfish
Pencilfish
Rasboras
Danios
Diminutive cichlids like Apistogramma or Mikrogeophagus
Health and Disease Prevention
Healthy Pastel Lily Tetras display vibrant coloration, active swimming, and alert behavior. Signs of illness include clamped fins, lethargy, loss of appetite, emaciation, or unusual spots or growths. Stable water parameters and a balanced diet prevent common fish diseases.
Quarantining new fish before introduction prevents pathogen spread. While no diseases are exclusive to Emperor Tetras, they can be susceptible to common freshwater ailments like Ich (white spot disease) and various bacterial or parasitic infections. Early detection and action prevent disease spread within the aquarium.
Breeding Pastel Lily Tetras
Breeding Pastel Lily Tetras is achievable in a home aquarium. Males typically display more intense coloration, elongated dorsal and caudal fins, and distinct blue eyes; females often have greener eyes and a thicker body.
To encourage spawning, a separate breeding tank with dim lighting, soft, acidic water (pH 6.0-7.0), and an elevated temperature (around 27°C/80°F) is beneficial. The breeding tank should include spawning mops or dense fine-leaved plants like Java moss, or a mesh bottom, to provide a substrate for egg deposition and protect eggs from adults.
After conditioning the pair with live foods, the female scatters adhesive eggs over several hours. Once spawning is complete, promptly remove adult fish to prevent egg consumption. Eggs typically hatch within 24 to 48 hours; fry become free-swimming in four to six days, then fed infusoria or newly hatched brine shrimp.