15721 Carcharhinus tilstoni (Whitley, 1950) Carcharhinidae Requiem sharks Carcharhiniformes Elasmobranchii Australian blacktip shark Indo-West Pacific: currently known only from the continental shelf of tropical Australia. Very similar to <i>Carcharhinus limbatus</i> and reliably distinguished only by biochemical studies and vertebral counts (Ref. 9819).