The Pseudomystus siamensis, commonly known as the Asian Bumblebee Catfish, is a freshwater bagrid native to the Chao Phraya and Mekong basins in Thailand and neighbouring countries. This species is characterised by a contrasting yellow-black pattern, discreet nocturnal behaviour and a moderate adult size (10-15 cm depending on conditions). The advertised size of 4-5 cm corresponds to a young specimen, perfect for starting out.

Behaviour & maintenance

• A rather nocturnal and benthic species: it remains hidden during the day and becomes active after the lights go out.
• Territorial towards congeners or similar bottom fish if space or hiding places are insufficient.
• A good candidate for intermediate aquarists: requires a suitable décor and compatible cohabitants (avoid small fish that could serve as prey).

Diet

• An opportunistic carnivore: in the wild, it feeds on aquatic insects and small invertebrates.
• In the aquarium: sinking pellets, catfish pellets, frozen food (worms, prawns) fed in the evening.
• Make sure it has access to its food in quiet or dark areas to limit competition.

Water quality

• Temperature: 20 - 26°C depending on the source.
• pH: around 6.0 - 8.0 (preferably 6.5-7.5); moderate GH.
• Very clean water, good moderate mixing, sandy substrate recommended.

Decor & environment

• Sandy subsoil or very fine gravel, plenty of dark hiding places (roots, PVC pipes, caves).
• Subdued lighting or shaded areas to respect its nocturnal behaviour.
• Recommended volume: for a group and optimal conditions, around 150-200 L or more, to limit conflicts and allow good growth.

Maintenance sheet

Aquabota tip

Although hardy, this fish needs a serious setup: choose a dark bottom, moderate lighting, and only introduce it into a well-stabilised tank. At night, they become active: a little blue or "moon" light will allow you to observe them. Avoid smaller species that could become its prey and provide several caves/tubes to limit conflicts between individuals.