Mahnert’s Loach (Schistura mahnerti)

The Mahnert’s Loach (Schistura mahnerti), often called the Tiger Loach or Burmese Border Loach, is a striking bottom-dweller prized for its bold black-and-white banding and playful personality. Native to fast-flowing hill streams in Southeast Asia, this hardy loach brings activity and algae control to high-flow, well-oxygenated aquaria. Below is an in-depth guide to keeping these captivating loaches healthy and thriving.

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Appearance & Size

• Scientific Name: Schistura mahnerti

• Common Name: Mahnert’s Loach, Tiger Loach, Burmese Border Loach

• Adult Size: 6–8 cm (2.5–3″)

• Coloration:

  • Pale cream to golden-yellow body

  • Distinctive vertical black bands (“tiger stripes”) along the body and tail

  • Red or orange accents on dorsal, pectoral, and caudal fins in well-conditioned specimens

• Sexual Dimorphism:

  • Males often display slimmer bodies and more intense red coloration on fins.

  • Females appear slightly rounder in the abdomen, especially when carrying eggs.

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Natural Habitat

• Geographic Range: Hill streams and tributaries in Myanmar (Burma) and northeastern India.

• Environment:

  • Fast-flowing, oxygen-rich streams with rocky substrates

  • Clear, cool waters (typically 18–22 °C) shaded by overhanging vegetation

  • Rocky crevices and riffles where they loaf during daylight and forage at dawn/dusk

• Behavior in the Wild:

  • Benthic foragers, scavenging in crevices for aquatic invertebrates and algae

  • Often found in small groups or pairs, preferring well-oxygenated pockets of current

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Tank Requirements

1. Tank Size:

   • Minimum: 80 L (20 gal) for a small group of 4–6 loaches

   • Ideal: 120 L+ (30 gal) to allow ample rockscaping and strong flow

2. Aquascape & Décor:

   • Substrate: Fine gravel or smooth river rock to prevent abrasion to barbels

   • Hardscape: Abundant smooth slate or driftwood arranged to create crevices, caves, and overhangs

   • Plants: Hardy, low-growing species (e.g., Anubias, Java fern) tied to rocks—avoid delicate mid-water plants that may be uprooted by strong flow

   • Lighting: Moderate intensity; floating plants (e.g., Amazon frogbit) can help diffuse bright light

3. Filtration & Flow:

   • Filter: High-output canister or powerhead-driven setup to simulate strong stream currents

   • Flow: Moderate to strong—ensure water circulates around rock crevices and provides oxygen-rich pockets

   • Aeration: Additional air stones or sponge pre-filters can enhance oxygen levels

4. Water Parameters:

   • Temperature: 20 – 24 °C (68 – 75 °F)

   • pH: 6.5 – 7.5 (slightly acidic to neutral)

   • Hardness: 5 – 12 °dGH (soft to moderately hard)

   • Ammonia/Nitrite: 0 mg/L; Nitrate: < 20 mg/L

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Diet & Feeding

• Natural Diet: Aquatic insect larvae, small crustaceans, algae, and biofilm scraped from rocks

• Captive Diet Recommendations:

  1. Staple Foods:

     • High-quality sinking pellets or wafers formulated for loaches or bottom-dwellers

     • Algae wafers for supplemental plant matter and grazing

  2. Protein Supplements (2× Weekly):

     • Frozen or live bloodworms, brine shrimp, and daphnia

     • Blackworms or tubifex for enhanced protein intake

  3. Vegetable Matter (1× Weekly):

     • Blanched zucchini or spinach slices; remove uneaten portions promptly

• Feeding Routine:

  • Offer small portions twice daily, ensuring food reaches the bottom quickly

  • Observe feeding spots—Mahnert’s Loaches often pick at algae and scour surfaces rather than compete aggressively

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Behavior & Compatibility

• Social Structure: Semi-gregarious—thrives in small groups of 4–6, reducing stress and encouraging natural foraging

• Temperament:

  • Generally peaceful but moderately active; may chase each other playfully when establishing hierarchy

  • Best kept with other non-aggressive, similar-sized fast-water species

• Tankmates:

  • Suitable companions include:

    • Hillstream loaches (e.g., Homaloptera sp.)

    • Small cyprinids (e.g., Danios, White Cloud Mountain Minnows)

    • Catfish that prefer cooler, well-oxygenated water (e.g., Corydoras habrosus)

  • Avoid large, aggressive cichlids or slow-moving species that can be outcompeted for food

• Territoriality:

  • Occasionally, dominant individuals may defend prime grazing spots or crevices—provide ample hiding places to diffuse competition

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Care & Maintenance Tips

1. Stable Water Quality:

   • Perform weekly 25 % water changes to maintain clarity and low nitrate levels

   • Use a reliable dechlorinator to neutralize chlorine and chloramine

2. Gradual Acclimation:

   • Float the transport bag for 15–20 minutes to equalize temperature, then use drip acclimation over 30 minutes to adjust to pH and hardness differences

3. Observational Checks:

   • Healthy Mahnert’s Loaches maintain crisp banding, active foraging, and cling to rocks in current

   • Pale or faded bands may indicate stress from poor water quality or insufficient hiding spots

4. Disease Prevention:

   • Quarantine new arrivals for at least 2 weeks, watching for signs of ich or bacterial infections

   • Maintain strong flow to prevent dead zones where detritus and waste accumulate

5. Grouping Strategy:

   • Introduce a full group (4–6 loaches) simultaneously to establish a stable pecking order and reduce bullying

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Health Considerations

• Common Issues:

  • Fin Rot: Monitor for frayed fins; treat with improved water quality, aquarium salt (0.3 g/L), and broad-spectrum antibacterial medication if necessary

  • Ich (White Spot Disease): Signs include small white spots on body and fins; treat by raising temperature to 26 °C and administering ich medication in a quarantine tank

  • Barbel Erosion: Ensure substrate is smooth and avoid sharp décor to protect the loach’s sensitive barbels

• Preventative Care:

  • Regularly vacuum substrate to remove uneaten food and waste

  • Inspect crevices and rock surfaces for early signs of fungal or bacterial growth

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Breeding (In Brief)

Breeding Schistura mahnerti in captivity is uncommon and challenging due to their preference for strong currents and specific environmental cues. The following guidelines may encourage spawning attempts in specialized setups:

1. Conditioning:

   • Collect a small group of juveniles and separate into a dedicated breeding tank (80 L) with high flow simulated by a powerhead

   • Provide rock slabs or slate plates angled to mimic spawning sites in nature

   • Condition with high-protein live/frozen foods (bloodworms, blackworms) for 2–3 weeks

2. Water Parameters:

   • Maintain temperature at 22 – 24 °C, pH ~ 6.8, GH < 6

   • Mimic rainy-season conditions by performing large water changes with slightly cooler water

3. Spawning Behavior:

   • If breeding occurs, pairs may deposit eggs on the underside of flat rocks or slate

   • Remove adults immediately after spawning to prevent egg predation; eggs hatch in ~ 48 hours under optimal conditions

4. Raising Fry:

   • Feed infusoria or liquid fry food for first week, then transition to newly hatched brine shrimp and micro-pellets

   • Maintain minimal water flow to avoid washing away delicate fry

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Where to Buy & Final Tips

• Source: At Aquatropics, Andy hand-selects Mahnert’s Loaches for crisp banding, active behavior, and overall vitality.

• Shipping: We package these loaches in well-oxygenated bags with temperature-buffering materials to minimize transit stress.

• Ongoing Support: For personalized advice on replicating high-flow hillstreams, dietary recommendations, or breeding inquiries, message Andy at Aquatropics—expert assistance is always available.