Taxonomy & naming
Rhadinoloricaria ommation was described by Nijssen and Isbrücker in 1988 and is recognised as valid by the Catalog of Fishes (Eschmeyer, CAS). The parenthetical authority — (Nijssen & Isbrücker, 1988) — reflects an original placement in a different genus, later recombined into Rhadinoloricaria, a genus of slim-bodied whiptails within the subfamily Loricariinae of the suckermouth-armoured catfish family Loricariidae.
Little literature exists for the species beyond the original description and standard taxonomic checklists; the principal modern reference is Ferraris (2003), the Checklist of the Freshwater Fishes of South and Central America.
Morphology
Rhadinoloricaria ommation reaches a maximum recorded length of 5.5 in standard length (FishBase, based on a male or unsexed specimen) — the largest size recorded among the cached members of the genus. It displays the elongate, depressed body and slender, tapering caudal peduncle typical of the Loricariinae, with bony dermal plating along the body and a ventral suckermouth.
Detailed meristic, osteological and colour characters are contained in the original 1988 description and are not reproduced in the readily available secondary sources; no data on live coloration or sexual dimorphism is published here.
Habitat
The species is a freshwater, demersal, tropical fish of the upper Amazon drainage, recorded from the lower Marañón River in Peru — within the Marañón ecoregion of the FEOW classification. As a bottom-dwelling loricariine it would be expected on sandy or detritus substrates in flowing water, but specific microhabitat, current, depth and water-chemistry data have not been published for R. ommation.
Feeding
No direct feeding study exists for Rhadinoloricaria ommation. FishBase assigns a model-based trophic level estimate of 2.5, consistent with the detritivore and biofilm-grazer ecology general to whiptail loricariines. This is an inference from the genus and subfamily rather than an observation of this species; dietary data are sparse.
Mating
No data on courtship or mating behaviour have been published for Rhadinoloricaria ommation.
Breeding
No data on reproduction, spawning mode, clutch size or parental care have been published for Rhadinoloricaria ommation. No reproductive mode is asserted here.
In the aquarium
Rhadinoloricaria ommation has no recorded presence in the ornamental-fish trade and no L-number. There is no published aquarium husbandry experience for the species, and no care recommendations can be given.
Conservation
The IUCN Red List assessed Rhadinoloricaria ommation as Least Concern, with the assessment dated 7 October 2020. CITES and CMS list the species as Not Evaluated. The Least Concern listing reflects the absence of evidence for significant range decline or major threats across its upper-Amazon distribution, rather than detailed population monitoring.