Taxonomy & naming
Pseudohemiodon devincenzii was originally described by Señorans in 1950. The Catalog of Fishes (Eschmeyer, CAS) confirms the valid combination Pseudohemiodon devincenzii (Señorans, 1950), the parenthesised authority indicating that the species was first placed in a different genus before being transferred to Pseudohemiodon. FishBase places it in subfamily Loricariinae of the family Loricariidae.
Pseudohemiodon is a genus of the whiptail subfamily Loricariinae, comprising flattened, sand-associated species. Ferraris's 2003 Check List (cited by FishBase) records the species' length data.
Morphology
Pseudohemiodon devincenzii reaches about 5.5 in standard length. It has the flat-headed, depressed, elongate body characteristic of the sand-dwelling whiptails of its genus — a form suited to lying flat over and partly burying itself in fine substrate. The body is armoured in bony scutes and tapers to a slender caudal region.
No reliable account of sexual dimorphism in P. devincenzii has been published. In several Pseudohemiodon and related loricariines the male broods eggs on the underside of the body, a habit that can be accompanied by seasonal development of enlarged lip or pectoral odontodes, but this has not been specifically documented for this species.
Habitat
The species is known from the Uruguay River basin in South America. FishBase classes it as a demersal freshwater fish of temperate climate, reflecting the subtropical position of the Uruguay drainage. As a flat-headed whiptail it is associated with sand and fine sediment, over which it rests and into which it burrows.
Beyond this substrate association, detailed microhabitat data (depth, current, and seasonal water chemistry at collection sites) have not been published in accessible sources.
Feeding
No species-specific feeding study has been published for Pseudohemiodon devincenzii. Members of the genus are sand-sifters that work over and through fine substrate, and the feeding ecology of this species is presumed to follow that pattern, but no documented diet or trophic-level figure is available for it specifically.
Mating
No data on courtship or mating behaviour have been published for Pseudohemiodon devincenzii.
Breeding
No breeding data — spawning mode, clutch size, or parental care — have been published for Pseudohemiodon devincenzii. Several loricariines, including members of this genus, are lip-brooders in which the male carries the egg mass attached to his underside, but no such observation is documented for this species in accessible sources.
In the aquarium
Pseudohemiodon devincenzii is not an established aquarium species, and no husbandry record specific to it exists. Its genus members are sand-sifters that bury themselves, so any captive setting would need a deep bed of fine sand; beyond that general inference, no documented keeping guidance is available, and specific recommendations would be speculation. The species should be regarded as one for which no reliable aquarium data have been published.
Conservation
The IUCN Red List assessed Pseudohemiodon devincenzii as Data Deficient (DD), with the assessment dated 18 February 2021. Data Deficient means there is insufficient information to evaluate its risk of extinction — the available data on distribution, population, and threats are inadequate for a category assessment rather than indicating either security or imperilment. The Uruguay River basin is subject to agricultural land-use change and damming, but the species' actual status remains unresolved.