Species delimitation in poorly-known and diverse taxa is usually performed based on monolocus, DNA barcoding-like approaches, while multilocus data are often used to test alternative species hypotheses in well-studied groups. We combined both approaches to delimit species in the Xenuroturris / Iotyrris complex, a group of venomous marine gastropods from the Indo-Pacific. First, COI sequences were analyzed using three methods of species delimitation, ABGD, PTP and GMYC to propose primary species hypotheses (PSH). Second, RAD-seq...