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Atlantic Oyster Drill

Urosalpinx cinerea

The Atlantic oyster drill is a small snail with a pointed, ribbed shell. (The Southeastern Regional Taxonomic Center, South Carolina Department of Natural Resources)
The Atlantic oyster drill is a small snail with a pointed, ribbed shell. (The Southeastern Regional Taxonomic Center, South Carolina Department of Natural Resources)

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.

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.

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.

Other Facts:

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

Sources and Additional Information:




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