Taxonomy & naming
Arhinoglanis relictus was described in 2026 by Carlos DoNascimiento, Arturo Ortega-Lara, José G. Albornoz-Garzón, Carlos Román-Valencia and Nathan K. Lujan, in a paper in the Zoological Journal of the Linnean Society titled 'Phylogenetic assessment and taxonomic description of the first scale-feeding candiru from west of the Andes.' It belongs to the family Trichomycteridae, subfamily Stegophilinae — the scale-eating and mucus-feeding parasitic catfishes, distinct from the blood-feeding Vandelliinae found elsewhere in the family.
In the Catalog of Fishes (Eschmeyer, California Academy of Sciences), both the genus Arhinoglanis and the species relictus carry the identical author citation 'DoNascimiento, Ortega-Lara, Albornoz-Garzón, Román-Valencia & Lujan, 2026' without enclosing parentheses — the convention used for a name in its original combination. This indicates the genus was very likely erected in this same 2026 paper alongside the new species, though the full text confirming this (and any other species placed in the genus) was not accessible for this article.
The holotype, CZUT-IC 24378, was collected from the Río Risaralda, La Virginia Municipality, Colombia, 1 mi downstream of its confluence with the quebrada Totui and 5 mi from the mouth of the río Cauca, at an elevation of about 1,253 meters. The Catalog of Fishes records Arhinoglanis relictus DoNascimiento, Ortega-Lara, Albornoz-Garzón, Román-Valencia & Lujan, 2026 as the currently valid name.
Morphology
No morphological description, measurements, or coloration details for Arhinoglanis relictus were accessible for this article beyond the Catalog of Fishes record. Genus-level, Stegophilinae species are typically small, elongate, scaleless catfishes with reduced or specialized dentition adapted for feeding on the scales or mucus of other fish, but no species-specific data can be confirmed here.
Habitat
Arhinoglanis relictus is known from the upper Cauca River basin in western Colombia, a trans-Andean drainage system — notable because most Stegophilinae diversity is documented from cis-Andean basins (Amazon and Orinoco) to the east, making this a biogeographically unusual record for the subfamily. The type locality lies at roughly 1,253 meters elevation in the Río Risaralda, a tributary system near La Virginia, Colombia. No water chemistry data have been reported.
Feeding
The paper describing Arhinoglanis relictus identifies it, in its own title, as the first confirmed scale-feeding candiru known from west of the Andes — meaning this species (unlike most Trichomycteridae) is documented as lepidophagous, feeding on the scales of other fish, a specialized parasitic strategy shared with other Stegophilinae genera such as Stegophilus. Beyond this headline finding, no further feeding details (prey species, feeding frequency, or attack behavior) were accessible for this article.
Mating
No courtship or spawning behavior for Arhinoglanis relictus was accessible for this article.
Breeding
Breeding biology is entirely undescribed for this species in the material available; it has never been kept or bred in captivity.
In the aquarium
Arhinoglanis relictus is not in the aquarium trade and has no husbandry record. As a documented scale-feeding parasite of other fish, it would in any case be unsuitable for community aquaria; genus-level, Stegophilinae are not kept in the hobby. No care guidance is offered here.
Conservation
Arhinoglanis relictus has not been assessed by the IUCN Red List and carries no formal conservation status. It is currently known only from its type locality in the upper Cauca River basin, western Colombia; no information on population size, trend, or threats has been published.