Chondrichthyan systematics in Brazil depicted: historical overview, research trends and future perspectives

Brazil comprises one of the world's biodiversity hotspots of the chondrichthyan fauna, currently with 12 orders, 44 families, 90 genera and over 200 species of sharks, batoids, and chimaeras. These species inhabit marine, estuarine and freshwater realms of coastal and oceanic zones from the North equatorial central to the South-western Atlantic Ocean. Reporting on species occurrence in Brazil goes back to the pre-Linnaean Period. The golden era of the European Zoological studies put in place the knowledge on the local fauna with many Brazilian endemic and native species being officially described. The birth of Ichthyology in Brazil in the early 20th th century, however, represents the milestone for the Chondrichthyan Systematics in the country when national scientists published the first list of species. This study provides an historical overview of the Chondrichthyan Systematics research in Brazil through a literature review of peer-reviewed publications in shark taxonomy, phylogenetics and morphology. Scientific trends of over 120-year period of dedicated investigations are herein pointed out regarding research scope and subject area, methodology, target study taxa, and gender diversity. Research recommendations and priorities are further given to assist researchers and interested stakeholders on future efforts in shark science and conservation in the country.