Taxonomy & naming
Otothyropsis dialeukos was described by Calegari, Morlis and Reis in 2017. It is placed in the subfamily Hypoptopomatinae of the Loricariidae — the group of small 'dwarf' suckermouth or otocinclus-type armoured catfishes — within the genus Otothyropsis, a small assemblage of miniature loricariids associated with the Río Paraná system.
The genus name Otothyropsis signals a resemblance to the related genus Otothyris among these dwarf hypoptopomatines. Beyond the original description, published taxonomic and ecological treatment of this species is limited, and detailed diagnostic notes are not reproduced in the sources available here.
Morphology
Otothyropsis dialeukos is a very small loricariid, reaching about 1.5 in standard length. It has the depressed, bony-plated body typical of the dwarf Hypoptopomatinae. Beyond its small size, detailed external morphology and coloration are not described in the sources to hand, and no sexual dimorphism has been documented.
Habitat
The species occurs in freshwater, demersal, subtropical habitat in the upper Río Paraná basin of Paraguay. It is a bottom-associated fish of this drainage. Specific data on water temperature, pH, hardness, and depth at the collection localities are not published in the available sources.
Feeding
No diet has been published for Otothyropsis dialeukos. Dwarf hypoptopomatines of this body form are generally biofilm and algae grazers that rasp surfaces in their habitat, but no feeding data specific to this species exists in the sources at hand, so its diet should be treated as unrecorded.
Mating
No courtship or mating behaviour has been described for this species. Nothing reliable can be said about its reproductive interactions.
Breeding
There are no published breeding accounts for Otothyropsis dialeukos. Reproductive mode, clutch size, spawning site, and parental care are all unrecorded in the available sources.
In the aquarium
Otothyropsis dialeukos is not established in the aquarium trade and no husbandry has been documented for it. Any care expectations would have to be inferred from related dwarf Río Paraná hypoptopomatines — clean, gently flowing freshwater with surfaces for grazing — but no tested aquarium parameters exist for this species.
Conservation
Otothyropsis dialeukos has not been evaluated by the IUCN Red List (status Not Evaluated), so no formal conservation category applies. As a recently described, narrowly known fish of the upper Río Paraná system in Paraguay, its population status and trends are undocumented. Broad-scale pressures on the Paraná drainage — agricultural runoff, sedimentation, and hydrological alteration — affect small benthic fishes of this kind generally, but no species-specific assessment is available.