Tamang Borneo sucker

About

A rarely traded hillstream loach from the Kapuas drainage of Indonesian Borneo, Hypergastromyzon humilis is a member of the family Gastromyzontidae and one of only two species in its genus. It is a small fish, topping out well under two inches, with the classic flattened body plan that defines its family: horizontal paired fins, a depressed head, and pelvic fins fused into a powerful suction cup that lets it grip smooth rock surfaces in fast-flowing water. Unlike the wide, papillated mouths of related genera like Gastromyzon, Hypergastromyzon has a noticeably smaller, simpler mouth measuring roughly a third to half the head width. In H. humilis, seven to eight pale bars run across the dorsal surface. A useful field mark for telling it apart from its only congener. Open-water swimming is not really in this fish's repertoire; it crawls over and under substrate rather than moving through the water column. In the wild the species exists in loose groups, and a small group is worth aiming for in the aquarium. Because it rarely appears in the trade as a target species, turning up instead as bycatch in Gastromyzon shipments, building a group takes patience. It is a delicate fish best kept alongside calm hillstream companions; dominant or boisterous tankmates are a poor match.