Abundance, distribution and reproduction of the Data-Deficient species (Squalus blainville) around Sardinia Island (central western Mediterranean Sea) as a contribution to its conservation

摘要: Data-Deficient (DD) species are currently under threat because of the paucity information regarding their abundance, distribution and biological traits. In this study we analysed temporal trends bioecological features DD shark, Squalus blainville. Biological fishery data were collected through two different scientific surveys spanning 1994–2018 commercial hauls around Sardinia Island (central western Mediterranean) from 2008 to 2018. The analysis based on abundance revealed a significant population decline over time. late attainment maturity low fecundity S. blainville suspected have contributed making it highly vulnerable overfishing. No bathymetric segregation by sex size was found. However, almost exclusive presence pregnant females south-west could be due sexual spatial segregation. This is also supported histological findings showing long-term sperm storage ensure persistence when males separated. documented species, its reproductive potential similarities in depth immature mature individuals indicate need for urgent protection plans Sardinian waters.