Borneo Sucker Loach

Looks how to spot one

Flattened hillstream loach

Small, flat and rounded from above, with wide fins that seal against stones like a suction pad. Colours vary by species; a typical traded fish such as G. ctenocephalus is dark with evenly spaced pale brown spots, creamy spots on the head and shimmering blue marks on the dorsal and tail fins. Females are a little larger and heavier.23

Personality what they are like

Peaceful toward other fish but mildly territorial with each other, holding favourite stones. In a group the small border disputes are part of their most interesting behaviour.23

Daily activity how busy a day looks

Busy daytime grazers that move over rocks facing into the current. They need fast, highly oxygenated water and plenty of grazing surface.23

Grooming and care the hands-on bits

Water: about 20 to 24 C, pH 6.0 to 7.5 (Loaches Online gives 7.0 to 8.0 for G. ocellatus), hardness 2 to 12 dGH. Oversized filtration and powerheads for a turnover of roughly 10 to 15 times the tank volume per hour, with frequent partial water changes.23

Home where they are happiest

A stream-style tank with a base of at least 60 x 30 cm (about 54 litres) for a small group, smooth pebbles and boulders, bright lighting for algae growth and strong current.23

Food basics what goes in the bowl

Mainly grazes algae and the tiny organisms living in it. Also accepts algae wafers, quality sinking foods, blanched greens and small frozen foods such as bloodworm, with plant-based foods forming the base.23

Company who they like around

Keep a group of four or more to see natural behaviour; some species even rest together in small loose groups. Best with calm fish that like cooler, fast water.23

The story where it all began

The genus was named by Albert Günther in 1874. Most of its roughly three dozen species were described only in the 2000s, largely through the work of Heok Hui Tan, which is why many aquarium fish are still sold under one loose name.1

Recognised by the official bits

Taxonomy

Genus Gastromyzon, established by Günther in 1874 with G. borneensis as type species; about 36 species recognised, most described by H. H. Tan between 2003 and 20061

Trade note

The name Borneo sucker is applied loosely to several Gastromyzon species, which are hard to tell apart2