Nucella

Nucella is a genus of marine gastropod mollusks in the family Muricidae, commonly known as murex or rock snails. The genus comprises a small number of species, the most recognized being Nucella lapillus, known as the dogwhelk, along with less widespread members such as Nucella emarginata and Nucella guttata. Members of Nucella are characterized by their solid, often discoidal shells that are typically darkly colored, with a high spire and a relatively broad aperture. They possess an operculum that is usually corneous and concentric.

These snails are carnivorous predators, feeding primarily on other bivalves and barnacles. They use their radula, a ribbon-like tongue bearing tiny teeth, to bore into the shells of prey. Nucella species also have a unique organ called the secretory gland, which produces acidic secretions that aid in dissolving the calcium carbonate of the prey's shell. The feeding behavior is often described as a slow, methodical drilling process that can take several hours to complete.

Nucella species are intertidal organisms, commonly found on rocky shores throughout the northern Atlantic Ocean, the Pacific coast of North America, and the Southern Ocean. Their distribution is largely restricted to temperate and subpolar waters, where they occupy a niche as an important predator in the coastal ecosystem. The presence of Nucella is often used as an indicator of healthy intertidal habitats and can influence the community composition of other shellfish and algal species.

While the genus does not hold major economic importance, it is of interest to malacologists and ecologists studying predator–prey interactions, shell morphology, and the effects of environmental changes on coastal biodiversity. The taxonomic status of several species remains under review, and ongoing molecular studies are refining the phylogenetic relationships within Muricidae.