Abstract Deriving from a larger investigation into the sources used by Leonidas of Byzantium for his second-century AD Halieutica , this article argues that handful passages in Aelian’s De natura animalium (3.18, 3.28, 10.13, 10.20, 11.21, 11.23–24, 12.24–25[24] and 12.27[25]) comprise coherent series indebted to same section Leonidas’ work. More importantly, all these accounts are ultimately d...