Taxonomy & naming
Parakysis notialis was described by Heok Hee Ng and Maurice Kottelat in 2003. It belongs to the Akysidae, the Asian stream catfishes, and the Catalog of Fishes lists it as the valid name. Wet Spot has offered it under its scientific name; the atlas knows no established English common name.
Morphology
FishBase gives a maximum length of 1 in SL for males or unsexed fish. That is an adult size, and it makes the species a miniature even by the standards of its family. Akysids as a group have a naked, tuberculate skin, a depressed head and a stout spine at the front of the dorsal and pectoral fins. Beyond size, the atlas holds no further description of this species.
Habitat
FishBase records the species as freshwater, demersal and tropical, known only from the Barito River drainage in southern Borneo. The type locality is the area of Tamiyang Layang in Kalimantan Selatan. No temperature, pH or hardness figures are recorded for it.
Feeding
No diet is recorded for this species. Small akysids generally take tiny invertebrates from the bottom, but no feeding observation exists for P. notialis itself.
Mating
Courtship has not been described.
Breeding
No spawning, egg or larval information is recorded. The species has not been bred in captivity to the atlas's knowledge.
In the aquarium
The species has been offered by a specialist store, so some fish reach hobbyists. With a maximum of 1 in SL it needs a small tank with gentle flow, fine substrate, leaf litter and quiet tankmates that will not outcompete it. No husbandry data are published for it.
Conservation
IUCN lists Parakysis notialis as Critically Endangered. The known range is a single drainage in southern Borneo, which leaves the species exposed to any habitat change there. Wild collection for the trade adds a further, if small, pressure on a fish known from so few places.