Taxonomy & naming
Triplophysa cakaensis was described by Cao Wenxuan and Zhu Songquan in 1988, part of a wave of Triplophysa descriptions from surveys of the Qinghai-Tibetan and adjacent plateaus through the 1980s and 1990s. It belongs to the family Nemacheilidae, the stone or brook loaches — by species count the largest family in the loach superfamily Cobitoidea, and one that has absorbed most of the old, broad genus Nemacheilus (and its near-synonym Noemacheilus) as taxonomists split it along regional and morphological lines. Triplophysa is itself one of the biggest genera to emerge from that reshuffling, with well over 150 described species spread across the plateaus and mountain drainages of China and Central Asia.
The species epithet cakaensis refers to its type locality, Cha Ka (rendered Ulan/Cha Ka) in Qinghai Province — a naming pattern typical of the many narrowly distributed Triplophysa described from single plateau springs, streams or lakes. As with much of this genus, the species is known mainly from the original description and subsequent regional checklists rather than a deep literature; the Catalog of Fishes is the governing authority for the current genus placement, and nothing in the available record suggests this combination has been revised.
Morphology
Triplophysa cakaensis is a small loach, reported at about 2.5 in standard length — modest even by the standards of this genus, which runs from tiny spring-dwelling dwarfs to comparatively robust plateau-lake forms. Like other members of the family Nemacheilidae it is an elongate, cylindrical to slightly compressed fish with a small, subterminal, sucker-like mouth and barbels around the snout adapted for picking food from stream substrates, and it lacks the erectile suborbital spine that defines the botiid loaches — that structure is a Botiidae feature, not a Nemacheilidae one.
Detailed morphological data for this specific species (fin ray and scale counts, colour pattern, precise body proportions) are not available from the sources consulted here, and it would be irresponsible to invent them. What can be said with confidence, extrapolated from the genus and family, is that it shares the near-scaleless or fine-scaled skin typical of nemacheilids, a trait that matters for husbandry and disease sensitivity in any related species that might be kept.
Habitat
The species is endemic to Ulan (Cha Ka) in Qinghai Province, on the Qinghai-Tibetan Plateau of western China — one of the highest and coldest inhabited freshwater environments on Earth, with plateau elevations commonly in the range of 3,000 to 4,000 metres or more. Triplophysa as a genus is characteristic of this plateau: most species occupy cool, clear, well-oxygenated streams, spring outflows and lakes, with a smaller number of cave-adapted (hypogean) species known from karst systems elsewhere in the genus's range.
No specific stream-level habitat description (substrate, flow regime, associated species) is available for T. cakaensis in the sources consulted, but its plateau setting strongly implies a cold, swift, highly oxygenated environment rather than anything resembling a warm, still tropical water body. Given the species' apparent single-locality endemism, its entire known habitat may be a single spring or short stream reach — a precarious situation shared by many narrowly distributed plateau Triplophysa.
Feeding
No diet-specific data have been recorded for Triplophysa cakaensis in the sources consulted. Nemacheilid stone loaches as a group, including most Triplophysa, are benthic micro-predators and grazers: they work the bottom of clear, fast water for small invertebrates such as insect larvae and crustaceans, along with algae and biofilm scraped from stones. It is reasonable to assume a similar diet for this species, but that is an inference from the genus, not a documented fact, and should be treated as such rather than as confirmed biology.
Mating
Nothing specific has been published on courtship or spawning behaviour for Triplophysa cakaensis in the sources available here. Across Nemacheilidae generally, reproduction is not built around pairing displays or nest construction; ripe adults come together over suitable substrate in flowing water and release eggs and milt with no extended courtship. There is no basis in the record for describing anything more particular for this species, and none should be invented.
Breeding
As with virtually all stone and brook loaches, Triplophysa cakaensis is presumed to be an egg-scatterer: adults broadcast eggs over gravel or among stones in flowing water, with no parental care of eggs or fry. This is the standard reproductive mode for Nemacheilidae and stands in clear contrast to the cave-guarding males of some gobies or the mouthbrooding seen in unrelated fish families — neither applies here or anywhere in this family.
There is no record of this species being bred in captivity, which is unsurprising: it is not established in the aquarium trade, its wild population is confined to a single site and assessed as Endangered, and even well-known Triplophysa are rarely spawned by hobbyists. For a plateau endemic this restricted, captive breeding — if it were ever attempted from surviving stock — would be a conservation measure rather than a hobby one.
In the aquarium
Triplophysa cakaensis is not a species found in the aquarium trade, and given its conservation status it should not be sought as one. It is included here for completeness of the Nemacheilidae record on this site, not as a care recommendation.
For context, the handful of Triplophysa species that do circulate in the hobby — and any hypothetical care of this one — would need cold-to-cool, clear, fast-flowing, highly oxygenated water rather than a standard tropical community setup, plus a fine sand or smooth gravel substrate and stable water quality; nemacheilid loaches in general are also scaleless-skinned fish that respond poorly to copper-based medications and full-strength treatments. None of this is a substitute for protecting the single wild population that this species still depends on.
Conservation
The IUCN Red List now assesses Triplophysa cakaensis as Endangered — a serious but not extinct status, superseding earlier national-level evaluations of China's continental fish fauna that had listed the species as possibly Extinct. As a species known only from a single locality — Ulan/Cha Ka in Qinghai Province — it remains exactly the kind of narrowly endemic plateau stream fish most vulnerable to local habitat change: water abstraction, damming, spring capture or pollution at a single site could still eliminate the entire species, with no possibility of natural recolonisation from elsewhere.
Given how recently the species was feared lost, continued fieldwork at or near the type locality remains valuable for tracking the health of this single known population and confirming its long-term persistence.