Mulberry Whelk

Morula marginalba, commonly known as "mulberry whelk", is a carnivorous species of sea snail, a marine gastropod mollusc in the family Muricidae, commonly referred to as "murexes" or "rock snails". It has a distinctive shell pattern with five spiral rows of nodules on body whorl, with a variable number of scaly ribs between. The shell is usually eroded, so this fine sculpture is normally not present. Size is usually less than 20 mm, but can grow up to 35 mm in length. This is a predatory species that feeds almost exclusively on molluscs and barnacles, and it's also found in estuaries where it is known as the "black oyster borer" because it feeds on oysters where it is regarded as a pest. It has an extensible rasping radula with which it drills a hole through it victim's shell. The process is believed to be assisted by the sulphuric acid it produces in its salivary glands which helps to soften and dissolve the calcium carbonate in the mollusc's shell. It then uses its radula to cut the soft body of its victim in pieces before sucking the semi-digested mass out. Nasty! PS: Not the best picture quality as rushed photos due to rising surf. I almost got drenched a couple of times, so this spotting was a hit-and-run.