Flying Fox
Epalzeorhynchos kalopterus
Also known as: Flying fox fish, Black-lined flying fox
Quick Facts
- Adult size: 14-16 cm (5.5-6.3 inches)
- Minimum tank size: 160 litres (42 gallons)
- Lifespan: 8–10 years
- Temperament: semi-aggressive
- Swimming level: bottom-and-middle
- Diet: omnivore
- Minimum group size: 1
- Difficulty: intermediate
Water Parameters
- Temperature: 20–26°C
- pH: 6–7.5
- Hardness (GH): 36–215 ppm (2–12 dGH)
Values above are general hardness (GH). For carbonate hardness (KH), the buffer that keeps pH stable, see the water parameters guide.
Care Summary
A slender, streamlined grazer banded with a bold black stripe and bright, black-tipped fins, the flying fox is a hardy cyprinid constantly confused with the Siamese algae eater, and the difference matters. The flying fox has a small flap of skin at each corner of the mouth, a smoother-edged stripe that stops at the tail base, and yellow-and-black fins, and crucially it is a less dedicated algae eater, grazing some as a youngster but switching to prepared foods with age, and it is more territorial. Reaching around 14 to 16cm, it becomes increasingly feisty toward other bottom-dwellers and especially toward similar-looking fish as it matures. It is best kept as a single specimen in a roomy, well-planted tank, or in a group of six or more to spread aggression, never in between. Hardy and handsome, but choose it for its looks, not as a cure for black beard algae: for that, buy a true Siamese algae eater.
Tankmates
Hardy and handsome, but territorial with age, especially toward other bottom-dwellers and similar-looking fish. Keep it as a single specimen, which is the usual recommendation, or in a group of six or more to spread the aggression, but never two to five, which leads to bullying. Avoid housing it with Siamese algae eaters, rainbow and red-tailed sharks, and other flying foxes. It suits a roomy, planted community of mid and upper-water fish such as rainbowfish, barbs, and gouramis, and it will harass dwarf shrimp.
Compatible with
Avoid keeping with
- Siamese Algae Eater
- Rainbow Shark
- Red-Tailed Black Shark
- Cherry Shrimp
- Large Cichlids
Common Problems
- territorial aggression toward similar-looking fish and other bottom-dwellers with age
- being bought by mistake instead of the true Siamese algae eater
- being expected to control algae, which it does poorly as an adult
- harassment of subdominant fish when kept in groups of two to five
Sources: seriouslyfish.com, fishbase.org · Last updated: 2026-10-13