The Dwarf Antenna Ray has only one congener, the Antenna Ray (Plesiotrygon iwamae). This species is reported to differ from it in colour, spiracles, snout, nasal curtain, and numbers of teeth, vertebrae and tail length (Last et al. 2016). Some researchers suspect that P. nana corresponds to a smaller-sized population of P. iwamae (P. Charvet unpubl. data 2021), since P. iwamae neonates and juveniles have extremely long filiform tails (over 10x disc width) and a clearly reticulated disc dorsal colour pattern (Charvet-Almeida 2001).

The Dwarf Antenna Ray (Plesiotrygon nana) is a small (to 52 cm disc width) Neotropical freshwater stingray patchily distributed in parts of the Upper Amazon River Basin. It is known only from freshwater habitats and apparently found in low densities. This species is caught for the international ornamental aquarium trade and is probably subject to persecution in some areas due to fear of sting injuries. Habitat loss and degradation over the last decades are significant threats for this species and are ongoing. Thus, considering the combination of lack of management and increase in threats along its distribution range, the Dwarf Antenna Ray is suspected to have undergone a population reduction of at least 20% over the last three generation lengths (29 years). Therefore, the Dwarf Antenna Ray is assessed as Near Threatened (close to meeting A2cd).

The Dwarf Antenna Ray has a patchy distribution and is known from the Upper Amazon River basin, in Peru (Nanay, Pachitea, Ucayalí, Amazonas Rivers; in the Huánuco and Loreto departments) and Colombia (Putumayo River, Isla Nueva; Amazonas River, Puerto Nariño-lago El Correo) (Ortega et al. 2012, Lasso et al. 2013, Last et al. 2016, P. Charvet unpub. data 2021). There is reference to a single specimen collected during the Calhamazon Project in the Solimões River, close to the mouth of Purus River (Amazonas State, Brazil) but this record is based solely on a photograph and this specimen was not analysed in the species description (Carvalho and Ragno 2011). Therefore, researchers (Lasso et al. 2013) have expressed doubts if this specimen corresponds to the Dwarf Antenna Ray or a young Antenna Ray (P. iwamae).

The Dwarf Antenna Ray does not seem to be a common species (Lasso et al. 2013). It is a species with low density and biomass, making it vulnerable to exploitation. The population trend is decreasing as this species is subject to habitat impact and degradation by activities such as deforestation and urban expansion (Lasso et al. 2013), and is taken by the international ornamental aquarium trade. Thus, the Dwarf Antenna Ray is suspected to have undergone a population reduction of at least 20% over the past three generation lengths (29 years).

The Dwarf Antenna Ray is a demersal species only known to date from freshwater habitats. It reaches a maximum size of at least 52 cm disc width (DW), males mature at approximately 18–20 cm DW and female size-at-maturity is unknown. Size-at-birth is approximately 7 cm DW (Lasso et al. 2013, Last et al. 2016). There are no age parameters available for this species, however, generation length was estimated as 9.5 years based on estimates of age parameters from similar sized species in related genera and families (Potamotrygonidae, Dasyatidae, and Urotrygonidae) (Lucifora et al. 2022).

The Dwarf Antenna Ray is caught with some regularity for the international ornamental aquarium trade (Carvalho and Ragno 2011, Lasso et al. 2013). Fisheries for this species are of concern since it is not a very abundant species. Negative fishery (tail mutilation, killing and discard) is a potential threat since it is commonly observed throughout the Amazon River basin (Araujo et al. 2004). Habitat loss and degradation have been occurring over the past decades and are ongoing due to deforestation and urban expansion (Ortega et al. 2016). In Peru, there is no ornamental export regulation for this species and therefore, there is no official data or control on the trade of this species.

The Dwarf Antenna Ray is valued in the international ornamental aquarium trade due to its small size and valued reticulated dorsal colour pattern. Since it is a small species it is not known to be used for consumption.

The Potamotrygoninae subfamily (referred as Potamotrygonidae) was listed under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendix III in 2017 mainly to improve trade data (CITES 2017). The Dwarf Antenna Ray was not included in this listing (CITES 2017). The Dwarf Antenna Ray was also not listed in the recent addition of Potamotrygon species under CITES Appendix II (CITES 2023). Management plans, specific legislation (both development and implementation), and community management are recommended. Also, habitat maintenance and conservation, including reduction of several environmental impacts are key for the survival of this species. Further research is needed on taxonomy, population size and trends, and life history, and catch rates should be monitored.