Siamese Algae Eater, lat. Crossocheilus oblongus- Crossocheilus oblongus distribution
Family: Cyprinidae;
Genus: Crossocheilus;
Species and synonyms: Siamese Algae Eater (Crossocheilus oblongus, SAE, Siamese Algae Eater, Crossocheilus siamensis).
GBIF:
Siamese Algae Eater (lat. Crossocheilus oblongus) is a species of ray-finned fish from the order Cypriniformes, family Cyprinidae, genus Crossocheilus. One of the most popular aquarium fish, known for its ability to eat algae.
Distribution. The natural range of Crossocheilus oblongus covers freshwater bodies of Southeast Asia: Thailand, Malaysia, Indonesia (Sumatra, Kalimantan), as well as southern China and Myanmar. It inhabits rivers and streams with clean water, fast currents and rocky or sandy bottoms rich in algae growths. Due to its popularity in aquaristics, the species has been introduced to some regions for algae control.
Care requirements. The Siamese Algae Eater is one of the most popular fish for controlling algae, especially filamentous algae and "black brush algae". For keeping a small group (from 3 specimens), an aquarium of 80 liters or more is recommended. Optimal water parameters: temperature 24–28°C, hardness 5–15 dGH, pH 6.5–8.0. Filtration, aeration, moderate flow and weekly water changes of 20–25% are required. Diet: algae, dry flakes and granules with plant components, live and frozen food (bloodworms, brine shrimp, tubifex). Adults reach a length of up to 15 cm. Lifespan with good care is 5–8 years.
Crossocheilus oblongus is one of the few fish that effectively eats filamentous algae and "black brush algae" (a complex of red algae). Unlike many other "algae eaters", it eats not only young growths but also tough fibrous algae. The fish is active during the daytime, stays in the lower and middle water layers, prefers aquariums with many shelters made of stones and driftwood. In the wild, it feeds on algae and small invertebrates, which it scrapes from rocks and plants.
The Siamese Algae Eater is a schooling fish, forming groups of up to several dozen individuals in the wild. When kept alone, it may become aggressive or timid. In a school, the fish are calmer and more active, and a hierarchy is established among them. It is not recommended to keep them with slow-moving and veiltail fish, as the algae eaters may nip at their fins in search of mucus and algae. They coexist well with most peaceful fish of comparable size: danios, tetras, rasboras, barbs, as well as other inhabitants of Southeast Asia.
Crossocheilus oblongus has a characteristic appearance: an elongated torpedo-shaped body of gray-brown color with a dark longitudinal stripe from head to tail. A distinctive feature is the black spot at the base of the caudal fin and the presence of a pair of barbels on the upper lip. Unlike similar species (e.g., Epalzeorhynchus kalopterus — "Flying Fox"), the Siamese Algae Eater has a straight lateral profile without a hump. Sexual dimorphism is weak: females are usually fuller than males, especially during spawning. Breeding in the aquarium is difficult and requires stimulation with hormonal drugs or special conditions.
Thanks to its effectiveness in controlling algae, the Siamese Algae Eater has become an indispensable assistant in planted aquariums. However, it is important to distinguish the true SAE (Crossocheilus oblongus) from its less effective imitations, such as the Flying Fox (Epalzeorhynchus kalopterus) or the False Siamese Algae Eater (Garra cambodgiensis). The true SAE has a characteristic black stripe running from the nose to the caudal fin, and a dark spot at the base of the tail.
Comparison of the algae eaters Crossocheilus oblongus, Epalzeorhynchos kalopterus, Garra cambodginiensis and Gyrinocheilus aymonieri
Siamese Fighting Fish, lat. Betta splendens