dog whelk

1971 January 14, Graham Chedd, Peter Stubbs, Gerald Wick (section editors), Monitor: Starving dog whelks grow teeth in the estuary, New Scientist, Volume 49, Number 734, page 57, A recent study of shell-shape in the dog whelk Nucella lapillus along the Bristol Channel suggests - that in progressively less saline conditions the species lives in a colonising situation, where periodic food shortages, rather than physiological limitations, decimate populations and sometimes lead to local extinction.