Description
Black Line Flying Fox
The Black Line Flying Fox, also known as the Flying Fox fish, has the scientific name Epalzeorhynchos kalopterus. It belongs to the family Cyprinidae and is native to Southeast Asia, including the Thai-Malay Peninsula, Borneo, Java, and Sumatra.
Overview
The Black Line Flying Fox is a sought-after freshwater aquarium fish valued for its algae-eating habits and distinctive appearance. It has an elongated, torpedo-shaped body with a flat underbelly, an olive to dark brown upper body, and a yellowish-white lower body. A prominent brownish-black horizontal line runs from the eye to the base of the caudal fin, accented by a golden stripe above. The dorsal, anal, and ventral fins are transparent with a thick black band and white edges, and the eyes may feature a reddish iris. Adults typically grow to 12–15 cm in length, though stunting can occur in undersized tanks. In the wild, they inhabit fast-flowing rivers and streams, grazing on algae-covered substrates, and may migrate to flooded areas during the rainy season. In aquariums, they can live 8–10 years with proper care. They are often mistaken for similar species like the Siamese Algae Eater (Crossocheilus oblongus) or Chinese Algae Eater (Gyrinocheilus aymonieri), but can be identified by their two pairs of barbels, clear fins with black edges, and distinct black-and-gold stripe pattern.
Care Requirements
Black Line Flying Foxes thrive in setups that replicate their natural fast-flowing river habitats. Key parameters include:
- Tank Size Minimum 150 litres for one; 200+ litres for groups. Base dimensions at least 120 x 45 cm to allow swimming space.
- Water Temperature 23–27°C
- pH 6.0–7.5
- Water Hardness 2–12 dGH
- Substrate Fine sand or smooth gravel; add rocks, driftwood, and broad-leaved plants for cover and grazing surfaces.
- Filtration & Flow Strong filtration with high water turnover (e.g., canister or powerhead) to create moderate current; excellent oxygenation is essential.
- Lighting Moderate; supports algae growth for natural foraging without encouraging excessive algae blooms.
- Use a secure lid, as these fish are adept jumpers. They prefer mature, cycled tanks and do not damage plants while grazing.
Maintenance
Routine maintenance is essential to maintain water quality in their active, current-loving environment:
- Perform 25–50% weekly water changes to maintain pristine conditions and simulate natural flow.
- Vacuum the substrate lightly to remove debris without disturbing grazing areas.
- Monitor parameters weekly with test kits; ammonia and nitrite should be 0 ppm, nitrates under 20 ppm.
- Clean filters monthly, ensuring beneficial bacteria are preserved.
- Introduce algae wafers or vegetable clips if natural algae is scarce, but control light and feeding to prevent overgrowth.
- Quarantine new fish to prevent diseases like ich or fin rot, which can stress these sensitive swimmers. Signs of stress include paling of the black stripe, lethargy, or hiding—address with improved flow or parameters.
Diet
As omnivores and effective algae eaters, Black Line Flying Foxes primarily graze on green algae, including string and brush types, though they are less voracious than Siamese Algae Eaters. Supplement with:
- Algae-based foods: Sinking wafers, spirulina flakes, or algae tabs (e.g., Hikari Algae Wafers).
- Vegetables: Blanched spinach, zucchini, lettuce, or cucumber slices—offer via veggie clip.
- Protein sources: Flakes, pellets, live/frozen foods like bloodworms, brine shrimp, tubifex, or small crustaceans/insects.
Feeding schedule: Small amounts 1–2 times daily; they forage constantly, so avoid overfeeding to prevent obesity or water fouling. They may ignore prepared foods if algae is abundant, but variety ensures balanced nutrition.
Behaviour and Compatibility
Black Line Flying Foxes are peaceful yet territorial bottom-dwellers, often schooling loosely in the wild but becoming aggressive toward their own kind in confined spaces, especially over prime grazing spots. They are active swimmers, darting through currents and rarely resting, but can become stressed in stagnant or cramped tanks, leading to faded colours or aggression.
Behaviour: Diurnal and bold; they spend time grazing substrates and mid-water foraging. Provide hiding spots (rocks/driftwood) to reduce territorial disputes. They are hardy but dislike sudden changes.
Compatibility: Best in community tanks with similarly sized, peaceful species.
- Suitable tankmates include:
- Barbs, danios, rasboras, and tetras (e.g., tiger barbs, zebra danios).
- Loaches, gouramis, angelfish, and bottom-dwellers like corydoras or kuhli loaches.
- Avoid fin-nippers (e.g., tiger barbs in large groups), aggressive cichlids, or very small fish/shrimp that could be nipped. Keep singly or in groups of 5+ in larger tanks (200+ litres) to diffuse aggression; pairs or small numbers often fight. Not ideal for nano tanks or heavily planted setups without open swimming space.
Reproduction
Breeding Black Line Flying Foxes in home aquariums is challenging and rarely documented, as they are not commonly captive-bred—most are wild-caught. They are believed to be egg-scatterers in the wild, spawning during the rainy season in fast-flowing, vegetated shallows.
- Sexing: Difficult; females may appear fuller-bodied when gravid.
- Breeding setup: Use a large, heavily planted tank (200+ litres) with strong filtration, dim lighting, and slightly cooler temperatures (22–24°C). Condition with live foods and frequent water changes to mimic rainy season.
- Spawning: Males chase females; eggs (up to hundreds) are scattered over substrate/plants without parental care—adults may eat them. Water hardness around 5–10 dGH and pH 6.5–7.0.
- Raising fry: Remove adults post-spawning; fry need infusoria or baby brine shrimp initially, hatching in 24–48 hours. Success rate is low without hormones or commercial breeding facilities. Hobbyists often rely on wild imports; artificial induction via hormones has been reported in farms but is not recommended for beginners.
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.
