Atlantic Oyster Drill

Urosalpinx cinerea

Quick Facts

  • Species

    Native

  • Habitat

    Lives on oyster reefs, rocks, pilings and bay grass beds in shallow waters.

  • Range

    Found year-round in the middle to lower Chesapeake Bay; cannot survive in the upper Bay’s low-salinity waters.

  • Diet

    Feeds mainly on oysters; will also eat barnacles, mussels and other small mollusks

  • Status

    Stable

The Atlantic oyster drill is a small, predatory snail with a pointed, ribbed shell. It lives on reefs, rocks and pilings throughout the middle and lower Chesapeake Bay.

Appearance

The Atlantic oyster drill grows to about 1 inch in length. Its oval-shaped shell varies in color from gray or purplish to tan or yellowish-white and has a pointed spire, or tip. The shell has 5 to 6 raised whorls; brown, spiraling vertical ribs; and a thin, flared lip with small teeth.

Feeding

Oyster drills feed mainly on oysters, but will also eat barnacles, mussels and other small mollusks. They secrete an enzyme to soften an oyster’s shell, then drill pin-sized holes through the shell to reach the oyster’s soft parts inside.

Reproduction and Life Cycle

Spawning occurs throughout the summer. Atlantic oyster drills lay distinctive leathery, vase-shaped eggs that attach to a hard surface. Larvae crawl from the eggs within 6 to 8 weeks.

Did You Know?

  • Oyster drills are gastropods, a type of mollusk that includes whelks, snails and slugs.
  • They are significant oyster predators, particularly in parts of the lower Bay.

Sources and Additional Information

Quick Facts

  • Species

    Native

  • Habitat

    Lives on oyster reefs, rocks, pilings and bay grass beds in shallow waters.

  • Range

    Found year-round in the middle to lower Chesapeake Bay; cannot survive in the upper Bay’s low-salinity waters.

  • Diet

    Feeds mainly on oysters; will also eat barnacles, mussels and other small mollusks

  • Status

    Stable