A ridged temperate whelk that hunts sea squirts, found on rock and on jetty pylons with its egg capsules beside it.
Shell between about 15 and 18 cm, commonly around 8. A solid spindle-shaped shell with strong spiral ribs and strongly nodular shoulders. The outer lip is thickened and toothed inside, and the column of the shell is smooth with a single tooth at the back. In life it is covered by a thin yellowish-brown skin, which is why living animals look drab and beached shells look bright.
Other Australian tritons are separated by the nodular shoulders and that single tooth, and by where it lives.
It eats sea squirts, almost exclusively the cunjevoi, and is found on exposed rocky shores among rocks and cunjevoi beds, intertidally and just below. It is the most common large sea snail on the rocky shores around Sydney and is easy to find at low tide. It has been recorded to 80 m but is almost always shallow.
It is a temperate animal of southern Australia and New Zealand, not a tropical reef species. It is sold for eating in fish shops in New South Wales.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.