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Keywords:

  • Squatinidae;
  • reproduction;
  • development;
  • delayed vitellogenesis;
  • gestation;
  • egg capsule;
  • lecithotrophy

Distribution, sexual maturity, fecundity, genital asymmetry, cyclic vitellogenesis and gestation are described in the angel sharks Squatina squatina (L., 1758) and S. oculata Bonaparte, I840 from Tunisian waters. With embryonic nutrition being purely lecithotrophic, lack of egg capsules, block of oocyte growth at the beginning of gestation, and inability to ovulate soon after parturition, Squatinidae can be compared to Torpedinidae and to Centroscymnus (Squalidae), except that their vitellogenesis starts again at mid-gestation. This new, special feature has been termed ‘semi-delayed vitellogenesis’ with regard to the delayed vitellogenesis of Torpedinidae and Centroscymnus.