Famous for being one of the few freshwater fish that actively consumes Black Beard Algae (BBA). A torpedo-shaped, active bottom-to-midwater swimmer native to Southeast Asian streams. True Siamese Algae Eaters feature a distinct black horizontal stripe that extends all the way through the tail fin. As they mature, they can become lazy, preferring prepared foods over algae, and may occasionally chase other bottom dwellers.
At a Glance
Tank Requirements
Water Parameters
Temperament & Compatibility
Available Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Standard
The standard true Siamese Algae Eater. Excellent algae grazers when young. Provide a tight-fitting lid as they are easily spooked and prone to jumping.
Differs in 1 trait from base species
Also known as: True Siamese Algae Eater, Juvenile SAE
Siamese Algae Eater Care Summary
The Siamese Algae Eater, scientifically known as Crossocheilus oblongus, belongs to the Cyprinids family group. Adults reach a maximum size of approximately 15 cm and have a fusiform body shape with a moderate growth rate. Classified as mostly peaceful, this species primarily occupies the bottom and mid-level zones of the aquarium and produces a medium level of biological waste.
To thrive, the Siamese Algae Eater requires a freshwater only aquarium with a minimum volume of 110 litres and a tank length of at least 90 cm. Water temperature should be maintained between 22°C and 28°C, with a pH range of 6–7.5 and a general hardness of 5–15 dGH. A moderate water flow is preferred. To replicate their natural habitat, the tank should include established algae (otocinclus), driftwood (digestion/hiding), and plants - lighly covered.
Siamese Algae Eater can be kept singly or in a group, making them flexible additions to most setups. Keepers should be aware that this species will defend a territory within the tank and is a known jumper, so a tight-fitting lid is essential. The Siamese Algae Eater is typically available in one standard form.
Similar Species
Betta (Siamese Fighting Fish)
Betta splendens
The Siamese Fighting Fish is an aquarium icon known for its labyrinth organ (allowing air breathing) and vivid colors. While hardy, they require heated, filtered water (24-30°C). Males are solitary and fiercely territorial. Females are generally less ornate but can be kept in 'sororities' with strict precautions (minimum 5 females in 75L+).
Pictus Catfish
Pimelodus pictus
An extremely active, striking silver catfish with black spots and incredibly long barbels, native to South America. While peaceful toward similarly sized tank mates, they are highly effective nocturnal predators that will easily swallow small fish (like Neon Tetras) whole. They are scaleless and possess sharp pectoral spines that can easily become entangled in aquarium nets.
Bumblebee Goby (Brackish)
Brachygobius xanthozonus
A miniature, bottom-dwelling goby famous for its striking black and yellow stripes. While they are often sold as freshwater fish and can survive in it temporarily, they are highly susceptible to fungal infections in fresh water and truly require a brackish setup (SG 1.002-1.005) to thrive long-term. They are notoriously picky eaters, often ignoring flakes in favor of live or frozen foods (like bloodworms or brine shrimp).
Florida Flagfish
Jordanella floridae
A robust, deep-bodied killifish native to Florida. Unlike most killifish, they are primarily herbivores and are renowned for their ability to eat Hair Algae and sometimes Black Beard Algae. They are sub-tropical and thrive in unheated aquariums. They can be fin-nippers, especially if underfed or kept with long-finned tank mates.
Scarlet Badis
Dario dario
One of the smallest known aquarium fish, resembling a tiny jewel. Males display brilliant vertical red and iridescent blue stripes. While beautiful, they are known for being extremely picky eaters, often refusing dry foods and requiring live or frozen micro-foods (Daphnia, Baby Brine Shrimp). Males act like tiny Cichlids and will stake out territories.
Dwarf Gourami
Trichogaster lalius
A peaceful to semi-aggressive labyrinth fish native to South Asia. Famous for their brilliant metallic blue and red stripes. While generally suitable for community tanks, males are territorial toward each other and similar-looking fish. They are sensitive to water quality and prone to Iridovirus if stressed. Requires access to the surface to breathe.