Siamese Algae Eater vs Flying Fox: Identification and Behaviour
Mislabelling between the Siamese algae eater and the flying fox is one of the hobby’s most persistent problems. The Siamese algae eater vs flying fox comparison matters because only one of these fish reliably eats the black beard algae that plagues planted tanks. Gensou Aquascaping at 5 Everton Park, Singapore has seen countless customers buy the wrong species, and this guide will help you avoid that frustrating mistake.
The Correct Species Names
The true Siamese algae eater (SAE) is Crossocheilus oblongus (also referenced as C. siamensis in older literature). The flying fox is Epalzeorhynchos kalopterus. A third look-alike, the false Siamese algae eater (Garra cambodgiensis), also turns up in shops. All three share a similar elongated body shape with a dark horizontal stripe, which is why visual identification requires attention to specific details.
How to Tell Them Apart
Focus on the dark lateral stripe. On a true SAE, the black stripe extends from the snout right into the caudal fin with a slightly ragged, zig-zag edge. The stripe on a flying fox is cleaner, straighter, and stops at the base of the tail. Flying foxes also display a prominent gold or orange band directly above the black stripe, which SAEs lack. Finally, check the mouth area: flying foxes have two pairs of barbels, while SAEs have only one pair. Examining these features under good light at the shop before purchasing saves a lot of frustration later.
Algae-Eating Ability
The true SAE is prized specifically for consuming red algae species, including black beard algae (Audouinella) and staghorn algae, which most other fish and invertebrates ignore. Young SAEs are voracious grazers. Flying foxes, by contrast, largely ignore red algae and prefer biofilm, green algae and prepared foods. As SAEs mature beyond 8-10 cm, their enthusiasm for algae often diminishes, and they shift towards pellets and other tank foods. Keeping them slightly underfed maintains algae-eating motivation.
Adult Size and Temperament
Both species grow to 12-15 cm, which surprises keepers who buy them as small 4 cm juveniles. SAEs remain relatively peaceful throughout their lives, though they become boisterous swimmers that may stress very timid tank mates. Flying foxes develop territorial aggression as adults and frequently chase other bottom-dwelling fish, including corydoras and loaches. A flying fox claiming a section of driftwood can terrorise nearby fish. For community tank harmony, the SAE is the safer long-term choice.
Tank Requirements
Given their eventual adult size and active swimming behaviour, both species need a minimum tank volume of 120 litres. They are strong jumpers, so a tight-fitting lid or mesh cover is essential. Provide a moderate to strong current using a canister or hang-on-back filter, as both species naturally inhabit flowing streams. Temperature of 24-28 degrees C suits both perfectly, requiring no heater in typical Singapore conditions. Include driftwood, smooth river stones and dense planting to create a natural environment.
Availability and Pricing in Singapore
True SAEs are stocked at most local fish shops, typically priced at $3-6 each. Flying foxes sell for similar prices. The problem is mislabelling; shops frequently mix species in the same tank under a generic “algae eater” label. Visit during quieter hours when staff can net specific fish for your inspection. Shops in the Serangoon North area and C328 at Clementi generally maintain better species identification than mass-market pet chains. Buying in person rather than online lets you verify identity before committing.
Can You Keep Them Together?
Housing SAEs and flying foxes in the same tank is not recommended. Both occupy similar niches, and the flying fox’s territorial nature creates conflict as both species mature. A group of three to five true SAEs in a spacious planted tank works well. They form a loose social group and spread their grazing across the tank efficiently. Avoid keeping a single SAE with a single flying fox, as the flying fox will typically bully the SAE away from favoured resting spots.
Making the Right Purchase
Before heading to the shop, save a reference photo on your phone showing the diagnostic features: stripe extending into the tail, ragged stripe edge, and single pair of barbels for the true SAE. Politely ask the staff to net a candidate into a clear container so you can examine it closely. A few minutes of careful inspection saves weeks of disappointment watching a flying fox ignore your black beard algae problem entirely.
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emilynakatani
Still Have Questions About Your Tank?
Drop by Gensou Aquascaping — most walk-in questions get answered in under 10 minutes by someone who has set up hundreds of tanks.
5 Everton Park #01-34B, Singapore 080005 · Open daily 11am – 8pm
