The aperture is usually crenulated in mature dog whelks, less often in juveniles.
The dog whelk lives in rocky shores, and estuarine conditions.
If waves are large or there is an excessive risk of water loss the dog whelk will remain inactive in sheltered locations for long periods.
Predators of the dog whelk include various species of crabs and birds.
Many predators cannot smash the strong shell of an adult dog whelk, but juveniles are vulnerable to attack from many predatory species.
In general, the dog whelk can be thought of as being vulnerable to birds when emersed, and to crabs when immersed.
Even at relatively low levels, TBT causes masculinization in female dog whelks.
TBT is harmful to some marine organisms, including the dog whelk.
Small mussels are also eaten by the dog whelk, Nucella lapillus.
The report stated that female dog whelks still grow penises even after a ban on tributyltin.