Siamese Algae Eater

fish description – Siamese Algae Eater Care Guide ($Crossocheilus\ siamensis$)

Category	Detail
Scientific Name	$Crossocheilus\ siamensis$ (often traded as $C.\ oblongus$)
Common Name	Siamese Algae Eater (SAE), True SAE
Origin	Rivers and fast-flowing streams of Southeast Asia (Thailand, Malaysia, Cambodia)
Adult Size	5–6 inches (13–15 cm)
Temperament	Peaceful, very active, constantly grazing, can be territorial toward its own kind
Lifespan	8–10 years
Care Level	Easy to Moderate (due to size and activity)

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Appearance and Sexual Differences

 

• Short Description: A slender, torpedo-shaped fish with a pointed snout and a light body. The key identification feature is the bold black horizontal stripe that runs from the tip of the snout all the way through the caudal (tail) fin, which has no other black markings.
• Coloration: Body is typically a light tan, gold, or silvery-grey, with a prominent black stripe. The fins are completely clear (uncolored). Females tend to be slightly larger and noticeably fuller-bodied than males, especially as adults (sexual maturity takes a long time).
• Fins: All fins are uncolored. Lacks the red/gold stripe or colored fins of common look-alikes (e.g., Flying Fox).
• Behavior: Extremely active, constantly grazing the substrate, rocks, and plant leaves. They are shoaling fish but can become territorial with their own species as they mature, requiring plenty of space and line-of-sight breaks. They are jumpers and must have a tight lid.

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Tank Requirements and Water Parameters

 

• Minimum Tank Size: 40 gallons long (150 liters) is highly recommended for a single adult due to their adult size and high activity level. If keeping a group, 80 gallons or more is best.
• Schooling: Best kept solitary (in smaller tanks) or in a large group of 5 or more (in very large tanks) to diffuse potential aggression/territoriality toward their own kind.
• Temperature: Tropical range: $75^\circ$–$81^\circ\text{F}\ (24^\circ$–$27^\circ\text{C})$.
• pH Level: Highly adaptable: 6.0 to 8.0 (ideally 6.5–7.5). They require strong filtration and a moderate to high water flow to replicate their natural stream environment. High water quality (low nitrates) is essential for their health.
• Aquascape: Requires a well-structured tank with plenty of driftwood, rocks, and hardy plants to provide surfaces for grazing and areas to hide/rest. Leave ample open horizontal swimming space. Substrate can be sand or fine gravel.

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Diet and Feeding

 

The Siamese Algae Eater is an omnivore that is highly effective at controlling algae, but requires supplemental food.

• Staple Diet: The bulk of their diet should be algae and biofilm. Supplement with high-quality sinking algae wafers and blanched fresh vegetables (e.g., zucchini, cucumber, spinach).
• Supplementation: Offer a balanced omnivorous diet, including protein-rich frozen foods occasionally: Bloodworms, Brine Shrimp, and Daphnia.
• Schedule: Feed once or twice a day. Note that as they age, they often prefer prepared food over algae, which may require you to fast them occasionally to encourage algae grazing.

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Compatibility

 

• Caution: Peaceful toward most fish but may be territorial toward its own species and other similar-shaped bottom-feeders (e.g., Flying Foxes). Their speed can disturb slower, shyer species. May eat small dwarf shrimp and their fry.
• Good Tank Mates: Robust, peaceful, and active community fish that can handle the current and compete for food. Examples include Rainbowfish, larger Tetras (Congo, Serpae), Danios, Loaches, and peaceful Gouramis.