Evolução e biogeografia do gênero de raias marinhas Hypanus Rafinesque, 1818 (Myliobatiformes, Dasyatidae)

Abstract

Stingrays of the genus Hypanus Rafinesque (1818) have distribution areas along Atlantic and Pacific coasts of the American continent, as well as a species at the Guinea Gulf, in Eastern Atlantic. Since most Hypanus species are classified under Data Deficiency (DD) at IUCN Red List of Threatened Species, there is a need to solve their taxonomic and geographic distribution issues for future evaluations of their conservation statuses. By studying mitochondrial genomes of all valid species (H. americanus (Hildebrand & Schroeder, 1928), H. dipterurus (Jordan & Gilbert, 1880), H. guttatus (Bloch & Schneider, 1801), H. longus (Garman, 1880), H. marianae (Gomes et al., 2000), H. rudis (Günther, 1870), H. sabinus (Lesueur, 1824), and H. say (Lesueur, 1817))) we delimited 14 lineages, and two of them are the species H. geijskesi (Boeseman, 1948) and H. colarensis (Santos et al., 2004), that used to belong to the genus Fontitrygon (Last et al., 2016), and were now allocated to the genus Hypanus. The species with the widest distribution, H. americanus, is a non-monophyletic group and the lineage that occurs south of Amazon river discharge to Southeastern Brazil is a yet undescribed species and sister to H. rudis, in Atlantic African coast. We examined specimens of the clade H. americanus (H. americanus, H. longus, and H. rudis) to describe a new species using an integrative approach of data from DNA barcode, morphology, and ecological niche modeling. Besides, we inferred Hypanus’ lineages divergence times and identified possible biogeographic barriers posed by the American continent: Isthmus of Panama, Florida Peninsula, Amazon River water discharge, distance between continents separated by the Atlantic and Pacific Oceans, and temperature limitations in Northern and Southern Hemispheres (temperate and tropical waters). The results indicate the geographic distribution of Hypanus species is smaller than previously defined, encompassing yet undescribed species. At the Brazilian coast there are six species of the genus, H. colarensis, H. geijskesi, H. guttatus, H. marianae, H. say, and H. sp. 1,with at least four endemic ones, including the newest herein described. Therefore, with the morphological, genetic, geographical distribution and identification of suitable habitats it is possible to accomplish an evaluation of the conservation status of some species que are classified under Data Deficient in IUCN, even though they are widely fished and consumed in the Brazilian coast.