Taxonomy & naming
Imperial Tropicals, Aqua Huna and Dan's Fish sell this loach as the Bloody Mary hillstream loach, Gastromyzon sp. "Bloody Mary". Imperial Tropicals also gives the name "red Lamandau hillstream loach". This is an undescribed form: its identity and range are not documented in the atlas's sources.
Morphology
Imperial Tropicals describes a dark brown or grey body crossed by sand-coloured bands, with blood-red dorsal and caudal fins. Dan's Fish describes deep red on the dorsal fin, the tail and the upper rear body. As in other Gastromyzon, the body is flattened, with fins spread against the substrate to form a sucker (genus-level).
Habitat
Sellers list it as coming from the headwaters of the Amandit River in the Lamandau regency of Borneo, in cool rapids. Gastromyzon as a genus are hillstream loaches of fast, well-oxygenated streams in Borneo (genus-level).
Feeding
Not recorded for this form. Gastromyzon graze biofilm and small invertebrates from rock surfaces (genus-level).
Mating
Not recorded for this form. Aqua Huna says the sexes are picked at random.
Breeding
Not recorded for this form.
In the aquarium
Dan's Fish lists the stock as harvested from nature, with an estimated shipping size of 1.25–1.75 inches (1–2 in) and an adult size of around 1.5–2 inches (1.5–2 in). Imperial Tropicals calls it uncommon and in demand among hillstream enthusiasts. Like other Gastromyzon, it is a fish for cool, fast, well-oxygenated water (genus-level).
Conservation
Sellers describe it as wild-collected. The form has no IUCN assessment, and its wild status is not documented.