Chondrichthyans from the southern tip of South America with emphasis on the marine protected area Namuncurá-Burdwood Bank: exploring egg nursery grounds

Abstract

The Burdwood Bank (BB) is a subantarctic area, where two of the three Marine Protected Areas (MPA) of the Argentinean Exclusive Economic Zone are located: Namuncurá I, and Namuncurá II. The area is characterized by a high biodiversity of benthic invertebrates and teleost fishes; however, the available information on oviparous chondrichthyans is scarce. The aim of this study is to explore the potential reproductive use that oviparous chondrichthyans could make of the area based on the presence of egg-laying grounds. Additionally, we aim to provide an updated checklist of the species that inhabit the BB. Samples of specimens and egg capsules collected in four research cruises carried out between 2016 and 2018 were analyzed. Six skate species were found in both MPAs: Amblyraja doellojuradoi, Bathyraja albomaculata, B. brachyurops, B. macloviana, B. scaphiops, and Psammobatis rudis; whereas B. cousseauae, and B. magellanica were found exclusively in Namuncurá I, and B. multispinis in Namuncurá II. Here we report, for the first time, the presence of egg-laying grounds for five chondrichthyan species in the BB area: A. doellojuradoi, B. brachyurops, B. macloviana, B. scaphiops, and P. rudis. The results obtained highlighted the importance of the region for the conservation of oviparous chondrichthyans found in the southern Patagonian shelf.