Fundy Region 


 Our Work 






Corophium Volutator

The unsung hero of the annual fall shorebird migration...

A prominent resident of the Bay of Fundy’s mud flats, the tiny invertebrate Corophium volutator. During summer, millions of these shrimp-like creatures cruise about the wet glistening muddy surface; it is one of the most abundant animals in the intertidal mud flats. About 5 mm long, this ant-sized crustacean eats bacteria, algae and other microscopic organisms churned up daily by the tides. Though seemingly insignificant in size, the mudshrimp plays a major role in the lifecycle of migratory shorebirds. Without them there would be no sandpiper stopover.

Mudshrimp dig U-shaped burrows in the mud flat. Not all mud flats are the same and, in fact, few mud flats contain the proper combination of coarse sand, fine silt and clay particles needed by mudshrimp to build and maintain stable burrows. In North America, Corophium volutator occurs only in the Bay of Fundy and the Gulf of Maine, where it is restricted to patches of mud where the quality of sediments is just right.

Corophium spends most of its life concealed in burrows. However, during its breeding season in early summer, this tiny creature devotes much of its time crawling about the surface of the mud in search of mates. Most retire to a burrow once the tide has fallen, but many remain on or near the surface of the exposed mud as they search for available burrows and mates, leaving themselves vulnerable to hungry sandpipers. On mud flats where Corophium do occur, the average density is between 10,000 and 20,000 per square metre of mud. When mudshrimp are breeding, one square metre of mud at a high quality site may contain as many as 60,000 Corophium!

A female Corophium shown in its protective U-shaped burrow.

Photo: Jim Wolford


Bay of Fundy

Upper Bay of Fundy


Text prepared by Nova Scotia Department of Natural Resources (NSDNR)
Graphics provided by NSDNR unless otherwise indicated
Web Design by CAPFLEX Networking
Page last updated 27 January, 2006 11:49 AM