Silver Flying Fox (Crossocheilus reticulatus)

Silver Flying Fox (Crossocheilus reticulatus) is a large, active Southeast Asian river fish recognised by its reticulated scale pattern and dark marking at the base of the tail. It is often bought as an algae grazer, but adult size, swimming needs and diet make it much more than a “clean-up fish”.

Choose the size option above for current supplied size, price and availability. These are juvenile delivery sizes; plan the aquarium around the adult fish.

What you are buying

• Scientific name: Crossocheilus reticulatus
• Common/trade name: Silver Flying Fox; sometimes sold as a reticulated algae eater
• Origin: Mekong and Chao Phraya basins
• Verified maximum size: FishBase records 17 cm standard length
• Habitat: clear, relatively fast rivers with gravel and boulders
• Diet: algae, periphyton and other small food items; not an algae-only diet
• Temperament: active and generally community-compatible with appropriately robust fish

Identification

Crossocheilus reticulatus is different from the better-known Siamese Algae Eater forms. FishBase describes a reticulated pattern created by dark scale margins and a prominent black blotch at the caudal-fin base. This pattern is useful when distinguishing it from striped Crossocheilus species.

Common names such as “Flying Fox”, “Siamese algae eater” and “algae eater” are used inconsistently in the aquarium trade. The scientific name on this listing is therefore important. Do not assume that every fish sold under a similar common name has the same adult size or behaviour. Compare the separately listed Siamese Algae Eater (Crossocheilus cf. langei) when checking which Crossocheilus you want; this comparison is not a tank-mate recommendation.

Adult size and aquarium planning

This is not a nano algae grazer. FishBase records a maximum of 17 cm standard length, and the fish is built for sustained movement in river habitats. For a group, Seriously Fish recommends an aquarium base of 180 × 45 cm or equivalent. Plan around this swimming footprint rather than treating a volume alone as sufficient.

A long aquarium is more useful than a tall narrow aquarium of the same volume. Leave open lanes for swimming and avoid filling the entire footprint with dense décor.

Flow, filtration and oxygen

Wild C. reticulatus occurs in clear, relatively fast water over gravel and boulders. In the aquarium, provide strong biological filtration, good surface movement and clean oxygen-rich water. The fish does not need to be blasted by a powerhead continuously, but stagnant low-oxygen conditions are a poor match for its natural ecology.

Use smooth stones, wood and robust planting to create grazing surfaces while retaining open water. A mature aquarium with established biofilm gives the fish more natural feeding opportunities than a newly scrubbed setup.

Water parameters

FishBase records 20–24°C for this species, while Seriously Fish gives a broader 16–24°C aquarium range. A stable range around 20–24°C is a practical planning target within both references, with near-neutral to moderately acidic/alkaline water generally workable when stable. This is guidance for aquarium planning rather than a claim about the full temperature tolerance of supplied fish.

Ammonia and nitrite should remain at zero. Keep nitrate controlled and avoid sudden chemistry changes. Good oxygenation becomes increasingly important as temperature rises.

Feeding and algae grazing

Silver Flying Foxes naturally take algae, periphyton and other small food items. That makes them useful grazers in a mature aquarium, but they should not be purchased as a guaranteed algae cure.

Provide a complete diet alongside natural grazing: quality sinking or midwater foods with algae or spirulina, plus blanched vegetables where accepted. Avoid making high-protein foods the staple; Seriously Fish cautions against their regular use for these grazers. Older fish may rely less heavily on nuisance algae than enthusiastic juveniles.

Do not underfeed the fish in an attempt to force more algae consumption. A hungry animal is not the same as an effective maintenance strategy.

Group behaviour

Crossocheilus are active social river fish, and a properly sized group can work well in a sufficiently large aquarium. Seriously Fish recommends six or more in a sufficiently spacious aquarium, so social attention is spread rather than concentrated on one companion.

If the aquarium is not large enough for a proper group, stocking should be planned carefully rather than automatically adding two or three fish. Watch for persistent chasing or one fish being excluded from feeding.

Tank mates

Choose active peaceful-to-robust fish that share similar water and oxygen requirements. Medium rasboras, barbs, rainbowfish and other river-oriented community fish can be suitable in a large aquarium.

Avoid very slow long-finned fish if the aquarium is crowded, very small tank mates that may be stressed by constant activity, and aggressive cichlids that monopolise the bottom or repeatedly attack the grazer.

Plants and aquascapes

Silver Flying Foxes work well in planted and river-style aquariums. Attach hardy plants to wood and stone, leave smooth grazing surfaces exposed and protect delicate newly planted stems if the fish repeatedly investigates them.

Because these fish are strong swimmers, keep a secure lid and cover gaps around pipes or cables. A startled river fish can jump.

Before ordering

Choose Crossocheilus reticulatus if you want an active river fish that naturally grazes algae and periphyton and you have enough aquarium length for its adult size. Reconsider if the tank is small, newly cycled or if the entire reason for purchase is the expectation that one fish will permanently eliminate algae.

Check the selected size option for current price and availability before ordering. Young fish still need mature grazing surfaces, suitable companions and space to reach their adult size.

References

FishBase: Crossocheilus reticulatus supports the wild distribution, identification and recorded maximum standard length. Seriously Fish: Crossocheilus reticulatus gives aquarium guidance on group size, swimming footprint and diet.