fish · Cyprinidae
True Siamese algae eater
Crossocheilus langei
Wild range: Borneo, Peninsular Malaysia, Sumatra; southern and western Thailand; possibly southern Myanmar (distribution of striped Crossocheilus in Thailand still under study) (Asia)
At a glance: True Siamese algae eater care
Compiled reference information. Review the care notes and original sources below.
What temperature is listed for True Siamese algae eater?
The compiled profile lists 20.0–26.0 °C for True Siamese algae eater (Crossocheilus langei). Check the original sources below for context and differing recommendations.
What tank size is listed for True Siamese algae eater?
The profile lists a minimum tank volume of 55.0 US gallons (208.0 liters). Volume alone does not establish suitability; consider dimensions, group size and other inhabitants alongside the full care notes.
What pH is listed for True Siamese algae eater?
The compiled profile lists a pH of 6.0–7.5. Review the cited care sources alongside the other water parameters in this profile.
Natural habitat
Flowing clear streams and tributaries with boulder/pebble/gravel/sand substrates, often with submerged wood or roots; browses biofilm and algae on hard surfaces in well-oxygenated current. May enter deeper, more turbid water during seasonal movements.
Where they are found
Valid name Crossocheilus langei Bleeker, 1860 (ITIS TSN 688915; Catalog of Fishes). Type locality Palembang, Sumatra. TRADE / TAXONOMY: widely sold as 'Siamese algae eater' (SAE), 'Siamese flying fox', or mislabeled Crossocheilus siamensis / C. oblongus. Seriously Fish notes C. oblongus (Java) was described as a blueish yellow-finned fish and is likely not the common aquarium SAE; the laterally striped trade fish is usually C. langei sensu amplo (or close undescribed forms) and is also confused with C. atrilimes and Garra / Epalzeorhynchos flying foxes. This catalog keeps a separate siamese-algae-eater (C. oblongus) row for the oblongus label; this entry is the true langei / typical BBA-grazing SAE of planted-tank literature. Distinguish from Chinese algae eater (Gyrinocheilus aymonieri), which grows larger and often becomes territorial.
Aquarium care
Plan a medium–large, well-oxygenated planted or river-style aquarium. Aquarium Co-Op recommends about 50–55 US gallons for a single adult SAE with a tight lid (known jumpers). Seriously Fish cites a ~150×45 cm base (~80 US gallons / ~304 L) for a group. This catalog uses 55 US gallons as the floor for one adult; keep groups of 6+ in substantially larger tanks with line-of-sight breaks. Provide rocks, driftwood, algae-friendly hardscape, strong filtration, and moderate flow with high dissolved oxygen. Spotless water—intolerant of organic waste buildup. Excellent grazers of black brush / beard algae when hungry (especially as juveniles); adults often prefer prepared foods, so reduce feeding if algae control is the goal. Do not treat as a nano 'cleanup crew' fish.
Feeding
Aufwuchs grazer (algae, diatoms, associated microorganisms) and opportunistic omnivore. Offer Spirulina-rich flakes/pellets, sinking algae wafers, blanched zucchini/spinach/peas, and modest live/frozen foods. Avoid relying on high-protein foods alone—Seriously Fish warns prolonged overfeeding protein can cause fat deposits. Supplement grazing; do not starve for algae control beyond short appetite resets.
Compatibility
Generally peaceful and community-safe with similarly sized, fast midwater fish (barbs, danios, loaches, robust livebearers). Shoaling rather than tight schooling—best in 6+ to dilute pecking-order bullying; a single specimen often does well alone (Aquarium Co-Op). May eat dwarf shrimp; usually leaves snails and larger shrimp alone. Avoid mixing with lookalike cyprinids (flying foxes, Garra, Chinese algae eaters) if identification or territorial friction is a concern. Pair with tankmates that can compete for food so SAEs do not monopolize meals.
Breeding
Not thought to have been bred in home aquaria; commercial farms use hormones (Seriously Fish). Mature females thicker-bodied; young cannot be sexed externally. Species undergoes seasonal reproductive migrations in nature.
Sources
Compiled from multiple independent care sheets — not copied from a single site.