Siqueira-Souza, M. & Amazonas, M.G. & Yamamoto, K.C. & Duncan, W.P. (2024)
Remodeling of Uterine Tissues During Gestation of Potamotrygon wallacei (Elasmobranchii), a Neotropical Freshwater Stingray Endemic to the Negro River, Central Amazonia. Journal of Morphology, 285(9), Article e21772
DOI: 10.1002/jmor.21772

Machado, R.N. & Duncan, W.P. (2024)
Morphology of the Digestive Tube of the Amazonian Freshwater Stingray Potamotrygon wallacei (Elasmobranchii: Potamotrygonidae): A Stereological Approach. Journal of Morphology, 285(9), Article e21771
DOI: 10.1002/jmor.21771

Shibuya, A. & Duncan, W.P. (2022)
Pre-copulatory bite wounds as evidence of aggressive competition for mating in the neotropical freshwater stingray Potamotrygon motoro. Acta Amazonica, 52(1), 45–48
DOI: 10.1590/1809-4392202101762

Duncan, W.P. & Machado, R.N. & Fernandes, M.N. (2021)
Environmentally-induced osmoregulation in Neotropical freshwater stingrays (Myliobatiformes: Potamotrygoninae) after controlling for phylogeny. Comparative Biochemistry and Physiology – Part A, Molecular & Integrative Physiology, 262, Article 111076
DOI: 10.1016/j.cbpa.2021.111076

da Silva, M.I. & de Oliveira, M.I. & da Costa, O.T. & Duncan, W.P. (2017)
Morphology and morphometry of the ovaries and uteri of the Amazonian freshwater stingrays (Potamotrygonidae: Elasmobranchii). The Anatomical Record, 300(2), 265–276
DOI: 10.1002/ar.23501

Duncan, W.P. & da Silva, M.I. & Fernandes, M.N. (2015)
Gill dimensions in near-term embryos of Amazonian freshwater stingrays (Elasmobranchii: Potamotrygonidae) and their relationship to the lifestyle and habitat of neonatal pups. Neotropical Ichthyology, 13(1), 123–135
DOI: 10.1590/1982-0224-20140132

Duncan, W.P. & Silva, N.F. & Fernandes, M.N. (2011)
Mitochondrion-rich cells distribution, Na+/K+-ATPase activity and gill morphometry of the Amazonian freshwater stingrays (Chondrichthyes: Potamotrygonidae). Fish Physiology and Biochemistry, 37(3), 523–531
DOI: 10.1007/s10695-010-9454-z

Duncan, W.P. & da Costa, O.T.F. & Sakuragui, M.M. & Fernandes, M.N. (2010)
Functional morphology of the gill in amazonian freshwater stingrays (Chondrichthyes: Potamotrygonidae): implications for adaptation to freshwater. Physiological and Biochemical Zoology, 83(1), 19–32
DOI: 10.1086/605458

Duncan, W.P. & Fernandes, M.N. (2010)
Physicochemical characterization of the white, black, and clearwater rivers of the Amazon Basin and its implications on the distribution of freshwater stingrays (Chondrichthyes, Potamotrygonidae). Pan-American Journal of Aquatic Sciences, 5(3), 454–464

Duncan, W.P. & Costa, O.T.F. & de Araújo, M.L.G. & Fernandes, M.N. (2009)
Ionic regulation and Na+-K+-ATPase activity in gills and kidney of the freshwater stingray Paratrygon aiereba living in white and blackwaters in the Amazon Basin. Journal of Fish Biology, 74(4), 956–960
DOI: 10.1111/j.1095-8649.2008.02156.x