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The taxonomic status of butterfly rays within the genus Gymnura remains a subject of ongoing debate among researchers. Some authors recognize up to five valid species for the Americas, while others considered several to be synonyms, which has posed a persistent challenge. We aimed to shed light on this complexity by employing molecular operational taxonomic units (MOTUs) based on the mitochondrial gene cytochrome oxidase I (COI). Genetic sequences were obtained from fresh muscle tissue collected in the marine ecoregions corresponding to the type locality from all the nominal butterfly ray species distributed along the Eastern Tropical Pacific (ETP). Our results unveiled compelling findings; all the species delimitation models used consistently identified seven MOTUs for the American continent and an extra G. altavela MOTU restricted to Africa. In addition, our results and models exceeded the worldwide accepted interspecific threshold of 2.0%. Remarkably, our results support the taxonomic reinstatement of Gymnura afuerae (Hildebrand, 1946) as a valid species, with a range expanding into the ETP in the Southern Hemisphere. Similarly, our data support the recent suggestion of resurrecting Gymnura valenciennii (Duméril, 1865) as a valid species in the western Atlantic. These findings urge a reassessment of the conservation status and a comprehensive taxonomic revision of American butterfly rays. [ABSTRACT FROM AUTHOR]

Although morphological abnormalities in several rays and skate species around the American continents have frequently mentioned, their numbers are unknown. The present work record morphological abnormalities in four Urotrygonidae species. Two anophthalmic specimens were detected (Urotrygon microphthalmum and Urobatis halleri). Two individuals lacked caudal fins (Urobatis maculatus and Urotrygon chilensis). Two round rays showed incomplete fusion of the pectoral fin to the head (U. microphthalmum and U. chilensis). Vertebral compression and fusion were found in a 6‐year‐old female Urotrygon rogersi. In addition, 118 abnormal batomorph specimens were gathered from the available bibliography, spanning the last six decades (1959–2021). Amblyraja doellojuradoi was the species with the highest number of abnormalities (18). The most common anomaly was an incomplete fusion of the pectoral fin with the head. Since 2010, at least 30 anomalous batomorphs have been recorded every 5 years. Sixty‐nine abnormal specimens occurred in the Northern Hemisphere (1.00–60.00 N). The Cortezian (Pacific) and Southeastern Brazil (Atlantic) marine ecoregions stood out with the highest number of these specimens. Mexico recorded 58 anomalous specimens, followed by Brazil (n = 36). Biological, abiotic and anthropogenic factors are probably the leading causes. However, additional studies are necessary to elucidate these speculations. [ABSTRACT FROM AUTHOR]

Urotrygon chilensis (Günther, 1872) was described based on a single specimen acquired by the British Museum of Natural History, London, from the Johan Cesar Godeffroy Museum in Hamburg. This medium-sized, benthic stingray is found along the eastern Pacific shelf (distance ranging almost 7000 km). During the last century, it has been frequently mentioned in the taxonomy and biogeography of Chile's marine fishes. However, since the original description in 1872, no other record of this species has been reported from Chilean waters. In this study, the historical presence of U. chilensis in Chile was confirmed based on three mature male specimens held at the Zoological Museum of the University of Hamburg (ZMH) collected in Taltal Harbour (Chile) in July 1894. According to the International Code of Zoological Nomenclature guidelines, we propose Taltal Harbour as the type locality of U. chilensis. Additionally, we conduct a historical review to determine how Albert Günther might have obtained the holotype. The discovery of these specimens catalogued in the fish collection at the ZMH is a demonstration of the important role that natural history museums play in documenting biodiversity patterns. The geographical distribution of U. chilensis is extended to the Central Chile marine ecoregion, approximately 1,500 km southward, from records in available databases. However, 126 years after its last recorded capture off Chile's coast, the historical presence of U. chilensis at such southern latitudes seems to reflect vagrancy in response to weather conditions. [ABSTRACT FROM AUTHOR]