Abstract
Longnose skates may have a high intrinsic vulnerability among fishes due to their large body size, slow growth rates and relatively low fecundity, and their exploitation as fisheries target species places their populations under considerable pressure. They are found circumglobally in subtropical and temperate coastal waters. Although longnose skates have been recorded for over 150 years in South America, the ability to assess the status of these species is still compromised by critical knowledge gaps. Based on a review of 185 publications, a comparative synthesis of the biology and ecology was conducted on two of the most commercially important elasmobranchs in South American waters, the yellownose skate <em>Zearaja chilensis</em> and the roughskin skate <em>Dipturus trachyderma</em>; in order to examine and compare their taxonomy, distribution, fisheries, feeding habitats, reproduction, growth and longevity. There has been a marked increase in the number of published studies for both species since 2000, and especially after 2005, although some research topics remain poorly understood. Considering the external morphological similarities of longnose skates, especially when juvenile, and the potential niche overlap in both depth and latitude occupied, it is recommended that reproductive seasonality, population structure and connectivity be assessed to ensure their long-term sustainability.
Highlights
Global threats to sharks, skates and rays have been increasing due to direct and indirect fishing effects (Pauly et al 2002, Worm et al 2006, Dulvy et al 2014)
For Z. chilensis, 77% of the articles correspond to scientific publications and 23% to ‘grey literature’ that comprised mostly fishery reports, covering almost 170 years since the original description
Available information concerning Zearaja chilensis and Dipturus trachyderma has been reviewed in a single assessment
Summary
Skates and rays have been increasing due to direct and indirect fishing effects (Pauly et al 2002, Worm et al 2006, Dulvy et al 2014). The biology and ecology of longnose skates is poorly known and requires further morphological, taxonomic and molecular research in spite of them being one of the largest taxa within batoids (Compagno 1999, Ebert & Compagno 2007, Séret & Last 2008) and have been subject to intense fishery exploitation (Baum et al 2003, Myers & Worm 2005, Myers et al 2007, Dulvy et al 2008, 2014, Ferretti et al 2008). The common skate Dipturus batis (Linnaeus, 1758), barndoor skate D. laevis (Mitchill, 1818), white skate Rostroraja alba (Lacepède, 1803), thornback ray Raja clavata L., 1758, smooth skate D. innominatus (Garrick & Paul, 1974) and longnosed skate D. oxyrinchus (L., 1758), are among the best documented examples of local extinctions in cartilaginous fishes as a result of fishing activities (Casey & Myers 1998, Francis et al 2001, Dulvy et al 2008, Dulvy & Forrest 2010)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
