Crossocheilus Oblongus

Crossocheilus oblongus, commonly known as the Siamese algae eater, is a compact, bottom-dwelling freshwater fish that brings natural algae control to your aquarium. This small, diligent grazer stays busy along the substrate, rocks, and plant surfaces, helping to keep visible algae growth in check so your tank stays cleaner between maintenance sessions.

In the wild, this tropical bottom-dweller is native to mainland Southeast Asia, including the Chao Phraya and Mekong basins and the Malay Peninsula. In captivity, it typically reaches a length of 3–5 cm, making it a versatile addition to many setups—from nano tanks to larger community aquariums.

• Efficient algae control: A reliable daytime grazer that feeds on common freshwater algae, helping reduce green film and diatoms on glass, décor, and plant leaves.
• Peaceful, community-friendly: Generally non-aggressive and compatible with a variety of peaceful tank mates, provided the aquarium is appropriately stocked.
• Compact, low-profile presence: Its small size (3–5 cm) makes it ideal for planted tanks and nano aquariums where space is at a premium.
• Hardy and adaptable: A tropical freshwater species that adapts to a range of routine aquarium conditions, supporting hobbyists of all levels.
• Natural behavior adds interest: Active during the day, it brings steady movement to the mid-to-bottom zones of the tank, enhancing the overall dynamics of your aquarium community.

This fish is an excellent choice for aquarists looking to balance algae management with a peaceful, visually appealing addition to the tank. Its bottom-dwelling habits mean it’s less likely to nibble on tender plants or disturb midwater-dwelling fish, while its modest size keeps it unobtrusive in moderately stocked setups.

Ideal use cases

• Planted aquariums seeking reliable algae control without aggressive tank mates
• Community tanks with small to medium-sized, peaceful fish
• Nano tanks where space is limited but algae management is desired

Care tips

• Provide a stable, well-filtered tropical environment and ample grazing surfaces (glass, rocks, driftwood, and plant matter) for consistent algae access.
• Offer a varied diet that includes algae-focused foods and supplemental proteins to support overall health.
• Keep stocking levels sensible to maintain harmonious tank dynamics and ensure enough algae growth for grazing.
• Include hiding spots and gentle décor to reduce stress and encourage natural foraging behavior.

With its small stature, peaceful temperament, and practical approach to algae management, Crossocheilus oblongus stands out as a thoughtful addition to a well-planned freshwater aquarium. If you’re aiming to reduce routine algae buildup while enriching your tank’s activity and biodiversity, this Siamese algae eater is a proven, low-maintenance choice that fits neatly into a variety of setups.