The intertidal nassariid Nassarius bicallosus lives on surf-exposed beaches across northern Australia including 80-Mile Beach near Broome in northwestern Western Australia. As the tide recedes, N. bicallosus emerges from the sand and feeds on a film of surface inorganic and organic particles, as confirmed by gut content analysis, but it may also be an opportunistic scavenger. Based on a review of feeding in nassariids, their widely reported habit of scavenging is probably and largely opportunistic in most taxa, although it appears to be obligatory in species of Bullia that are similarly occupants of surf beaches in South Africa.