Nassariidae in the context of "Aperture (mollusc)"

The Nassariidae, Nassa mud snails (US), or dog whelks (UK) are a taxonomic family of small to medium-sized snails, mostly marine gastropod mollusks in the clade Neogastropoda. These snails have rounded shells with a high spire, an oval aperture, and a siphonal notch. This family of snails is found worldwide.

These snails are found mostly in shallow water, on sandy or muddy substrates, often intertidally, but sometimes in deep water. They can be present in very large numbers in suitable habitat. Nassariidae are primarily active and lively scavengers.