Map of Donax deltoides collection sites from south-eastern Australia. G, Goolwa; C, Coorong; N, Nelson; L, Lake Monibeong; V, Venus Bay; P, Paradise Beach; E, Eden; G, Gerroa; KI, Kingscliff; KB, Killick Beach; F, Fraser Island. Color coding of collection sites correspond with genetic clusters identified by Bayesian analyses (blue, western population; green, eastern population; red, admixed genotypes). Solid red lines represent the direction of dominant ocean currents (SAC = South Australian Current; EAC = East Australian Current), dashed red lines represent the direction of genotype influx into Bass Strait, and rotating red arrows represent the contact zone between the isolated western and eastern populations.