The Leiocassis or Pseudomystus siamensis, (Name in Thai “แขยงหิน”) is native to the lower Mekong river running through Thailand, Laos, Cambodia, and Vietnam. It’s also found in the Chao Phraya river in Thailand.

The taxonomy regarding this genus is a bit confused and uncertain. It is often confused with the bumblebee catfish. There is little information and images, as it is not yet a very well known species in the aquarium. It has a long yellow or white-colored body with irregular bands that can be black or ash in color and can change according to the fish’s mood, age, size, and gender.  

Bumblebee Catfish inhabits sluggish streams and tributaries. It lurks among submerged tree roots and other refuges during daylight hours, emerging at night to feed.

Bumblebee Catfish Color has irregular vertical bars on a yellowish to the dark grey background (sometimes plain dark body); hyaline caudal fin with or without a single black blotch on each caudal lobe.

Dorsal spines (total): 1-1; Dorsal soft rays (total): 7-7; Anal soft rays: 16-17. Short barbels (maxillary barbels not reaching the pectoral spine); body depth at dorsal-fin origin larger than head width; a high, rounded adipose fin.

Maximum Standard Length – 6″ (15cm).


It’s a shy, nocturnal species, so it’s best to keep the tank dimly lit. Provide plenty of hiding places using upturned flowerpots, lengths of plastic piping, tangles, driftwood, etc. Plants aren’t essential but are useful in cutting out the amount of light hitting the bottom of the tank and providing extra cover. If you’re keeping it alongside other similarly-sized catfish, or as a species group, arrange the decor to form distinct territories. Try to position the heater in such a way that the fish will not be tempted to rest under it, as it’s a scaleless species and will burn easily.

Water Conditions

Temperature: 20.0-26.0°C or 68-78.8°F

pH: 5.8 to 7.8. Does best in acidic conditions.

Hardness: 4 to 25°H


Predatory by nature, but usually adapts well to dead foods in captivity. It relishes meaty items such as prawns, mussels, cockle, lancefish, or earthworms. Most specimens will also take dried sinking foods. When first introduced, it may only feed after lights out, and food should be added accordingly.


Not reported but would appear to be a substrate spawner laying its eggs in tangled roots in the wild. Maybe The p.H.would need to be on the acid side for any success with this species. There is a fleshy appendage in front of the anal fin that would indicate sexual dimorphism, which has been noticed in other Bagrids. But in the wild, in the rainy season, they lay up to 500 eggs in June and July. The fishermen easily find the small fry in their nets in August.

 Stamp of Thailand showing Bumblebee Catfish
Stamp of Thailand showing Bumblebee Catfish

By fishexp