“…In general, the most documented morphological abnormalities in American cartilaginous fishes are related to albinism (e.g., Anislado‐Tolentino et al., 2016; Becerril‐García et al., 2017; Escobar‐Sánchez et al., 2014; Jones et al., 2016), incomplete fins fusion (e.g., Hauser‐Davis et al., 2020; Mejía‐Falla et al., 2011; Rolim et al., 2020; Torres‐Huerta et al., 2015) and bicephaly (e.g., Ehemann et al., 2016; Galván‐Magaña et al., 2011; Sans‐Coma et al., 2017). The causes of such anomalies remain uncertain; however, most authors agree to hypothesize an effect of nutrition issues, genetic disorders, embryo development and water pollution as the main probable causes (e.g., Becerril‐García et al., 2017; Hauser‐Davis et al., 2020; Sans‐Coma et al., 2017; Torres‐Huerta et al., 2015). The present work aimed to document several morphological abnormalities observed directly on free‐living specimens of Haller's round ray Urobatis halleri (Cooper, 1863), the spotted round ray Urobatis maculatus Garman, 1913, the smalleyed round stingray Urotrygon microphthalmum Delsman, 1941, the blotched stingray Urotrygon chilensis (Günther, 1872) and the thorny stingray Urotrygon rogersi (Jordan & Starks, 1895), all of which are endemic species of the American continent belonging to the Urotrygonidae family.…”