New insights into the reproductive biology of the blue shark (Prionace glauca) in the South Atlantic Ocean

Size structure, age, and growth of the blue shark, Prionace glauca (Linnaeus, 1758) in southern Brazil

“…The higher proportion of males in the catches (9.86:1) indicates a pattern of sexual segregation, with males dominating the area throughout the year, especially in autumn. This is consistent with the findings of Mas et al (2023) for the southwestern Atlantic Ocean, where males also dominated the catches. Additionally, there are signs of size‐related segregation for males during summer, with adults making up the majority of the catches and very few juveniles in the area, whereas the opposite pattern is observed during winter.…”

“…The species also undergoes seasonal latitudinal migrations observed on both sides of the Atlantic and the Pacific oceans (Adams et al, 2016; Coelho et al, 2017). In the southwestern Atlantic Ocean, several studies (Carvalho et al, 2011; Hazin et al, 2000; Joung et al, 2017 and Mas et al, 2023) propose a size segregation pattern of male blue sharks in which the mean sizes increase as latitude decreases. Therefore, based on the results of this study, we hypothesize that a new batch of large juvenile male blue sharks arrives in the region (27–39°S) during autumn and remains through the winter to feed and grow.…”

“…In 2014, the species was locally assessed as vulnerable (VU) according to the IUCN criteria (Decree 51797, RS, 2014). Coelho et al (2017) and Mas et al (2023) have shown that juveniles are the main blue shark catches in the southern portion of the southwestern Atlantic (south of 32 S). However, both analyses considered large-scale spatial resolutions, which may result in the loss of finer-scale processes.…”