A few sub-adults of the Antarctic toothfish (Dissostichus mawsoni) were collected by bottom trawling carried out by the RV Polarstern in the southern Weddell Sea (Subarea 48.5) (PS82, ANT-XXIX/9, 19 December 2013 - 5 March 2014). Fishes were caught on the shelf and slope off the Riiser-Larsen Ice Shelf. In this document we report first data on individual age, gonad stage of maturity and diet through otolith readings, histological and stomach content analyses, respectively. All specimens were immature, showing an age range of 10-13 years. Main prey consisted of Antarctic silverfish and daggertooth.