The Siamese Algae Eater, scientifically known as Crossocheilus oblongus, is a highly effective freshwater fish for algae control, native to the rivers and streams of Thailand, Malaysia, and Indonesia. Known for its constant grazing behavior and peaceful nature, this species is a popular choice for planted and community aquariums.

Physically, Crossocheilus oblongus has a long, slender body with a silver-gray coloration and a distinct black horizontal stripe running from its snout to the base of its tail. This stripe remains solid throughout its life, differentiating it from similar species like the Flying Fox (Epalzeorhynchos kalopterus), which has a fading or incomplete stripe. Siamese Algae Eaters grow to about 5 to 6 inches (12 to 15 centimeters) in length, requiring a spacious tank to accommodate their active nature.

In the aquarium, Siamese Algae Eaters require a minimum tank size of 30 gallons, though larger tanks are preferred for long-term care. They thrive in well-oxygenated water with moderate to strong flow, mimicking their natural river habitats. A soft sand or fine gravel substrate is ideal, along with driftwood, plants, and rock structures to provide hiding spaces. These fish are highly active swimmers and require open areas for movement.

Water parameters should be stable, with a temperature range of 75 to 82°F (24 to 28°C), a pH between 6.0 and 7.5, and soft to moderately hard water. Consistent water changes and strong filtration help maintain water quality, as these fish are sensitive to poor conditions.

Feeding Crossocheilus oblongus is simple, as they are omnivorous and thrive on a diet of algae, biofilm, and plant matter. While they consume algae naturally, they should also be offered high-quality sinking pellets, spirulina wafers, blanched vegetables like zucchini and spinach, and occasional protein sources such as bloodworms or brine shrimp. A varied diet ensures they receive proper nutrition and prevents them from relying solely on aquarium algae.

Siamese Algae Eaters are peaceful and do well in community tanks with other non-aggressive fish. They coexist well with tetras, rasboras, gouramis, corydoras, and similar-sized fish. However, they should not be kept with territorial or overly aggressive tank mates, as they may become stressed or outcompeted for food. Keeping them in small groups of three to five individuals can encourage more natural social behaviors.

Breeding Crossocheilus oblongus in home aquariums is extremely rare and has not been widely documented. Most specimens available in the aquarium trade are wild-caught or bred in commercial breeding facilities using hormone induction.

Overall, Crossocheilus oblongus (Siamese Algae Eater) is a hardworking and beneficial species for aquariums, particularly in planted setups where algae control is a priority. Their active swimming behavior, peaceful nature, and efficient algae-eating abilities make them a valuable addition to a well-maintained freshwater tank.