Description
Glowlight Tetra (Hemigrammus erythrozonus)
Overview
The Glowlight Tetra (Hemigrammus erythrozonus) is a small, peaceful, tropical freshwater fish native to the Essequibo River basin in Guyana, South America. Growing to 4–5 cm, it features a silvery, semi-transparent body with a striking iridescent orange-red stripe from snout to tail, resembling a glowing filament. Its peaceful nature, vibrant colouration, and schooling Behaviour make it a popular choice for community aquariums, suitable for beginners and experienced aquarists. Introduced to the aquarium trade in 1933, it is widely available and often captive-bred, with albino and golden varieties occasionally sold.
Care Requirements
Tank Size:
Minimum 60 liters with at least 60 cm frontage for a group of 6–10 fish. Larger tanks (70–100 liters) are preferred for active swimming and shoaling.
Water Parameters:
- Temperature: 22–28°C, ideally 25–27°C
- pH: 5.5–7.5 (slightly acidic preferred, 6.0–7.0 optimal for breeding)
- Hardness: 2–15 dGH (soft water, 4–8 dGH for breeding)
- Nitrate: <50 mg/L
- Use a dechlorinator (anti-chlorine agent) during water changes to neutralize tap water.
- Filtration: Hang-on-back or sponge filter with gentle flow to maintain clean water without strong currents.
- Substrate: Dark, fine sand or gravel to enhance colouration and mimic natural riverbeds. Avoid bright substrates.
- Décor: Heavily planted tank with fine-leaved plants (e.g., Java moss, water wisteria, hornwort) and floating plants (e.g., Salvinia) for cover and dim lighting. Add driftwood, small rocks, or dried leaves (e.g., beech, oak) to simulate blackwater conditions with tannins. Ensure open swimming areas.
- Lighting: Dim or subdued to highlight their glowing stripe and reduce stress. Floating plants or partial lighting can achieve this.
- Cover: Secure lid required, as they may jump when startled.
Maintenance
- Water Changes: Replace 20–30% of water every 1–2 weeks to maintain quality and prevent ammonium/nitrate buildup.
- Tank Cleaning: Remove bottom sediment and clean filter media regularly. Avoid overstocking to minimize pollution.
- Monitoring: Use a reliable water testing kit to check temperature, pH, hardness, and nitrate levels weekly, as stable conditions are crucial despite their hardiness.
- Health: Watch for signs of stress (fading colours, skittish Behaviour) or diseases like ich (white spots). Quarantine affected fish to prevent spread.
- Lifespan: 2–5 years with proper care, occasionally longer in optimal conditions.
Diet
- Natural Diet: Omnivorous, primarily feeding on aquatic insect larvae, small crustaceans, and plant matter in the wild.
- Aquarium Diet: Accepts a variety of foods:
- High-quality flakes or micropellets (e.g., Hikari Micro Pellets) as a staple.
- Live or frozen foods (brine shrimp, daphnia, bloodworms, mosquito larvae) for nutrition and colour enhancement.
- Occasional vegetable matter (e.g., blanched spinach) or algae-based foods to vary diet.
- Feeding Frequency: Small portions 2–3 times daily to prevent overfeeding and water pollution. Surface feeders; ensure food doesn’t sink uneaten.
- Variety: A diverse diet promotes vibrant colouration and health. Avoid over-reliance on dry foods to prevent deficiencies.
Behaviour and Compatibility
Behaviour:
Peaceful, active, and shoaling, requiring groups of at least 6–10 (preferably more) to feel secure and display natural Behaviour. Solitary or small groups lead to stress, skittishness, and disease susceptibility. They swim in mid-to-upper water layers, often in tight schools when comfortable, but may hide if startled. Slightly shy but more confident in planted, dimly lit tanks.
Compatibility:
- Ideal for community tanks with similar-sized, non-aggressive species. Suitable tankmates include:
- Small tetras (e.g., Ember Tetras, Rummy-Nose Tetras), rasboras, danios
- Peaceful bottom-dwellers (e.g., Corydoras, smaller Loricariids)
- Small livebearers (e.g., guppies, platies), gouramis, dwarf cichlids (e.g., Apistogramma, Bolivian Rams)
- Avoid large, predatory, or boisterous fish (e.g., large cichlids, barbs) that may intimidate or eat them. Do not mix with Neon or Cardinal Tetras if hybridization or shoaling conflicts are a concern, though they can coexist in large tanks.
- Mixing Species: Avoid mixing with closely related species to prevent hybridization. Ensure tank size accommodates multiple shoaling species to avoid territorial disputes.
Breeding Behaviour
Reproduction: Moderately difficult but achievable with proper setup. Egg scatterers, laying 60–150 light-sensitive eggs over plants or spawning mops. Parents provide no care and may eat eggs, requiring removal post-spawning.
Picture for illustrative purposes only. Either come in store to view available stock or request pictures to be sent to you.
Please Note: Due to variations within species resulting from age, region, sex, etc., the actual livestock may not look identical to the image. Approximate size range may also vary between individual specimens.
