Meeting Abstract

11.4  Tuesday, Jan. 4  Finding Refuge: factors influencing the estuarine distribution of the nemertean egg predator Carcinonemertes errans on its crab host, Cancer magister DUNN, Paul H.; University of Oregon pdunn@uoregon.edu

The nemertean worm Carcinonemertes errans has been shown to be an egg predator on the Dungeness crab, Cancer magister. Worms feed by crawling into the berry of female crabs and consuming the crab eggs. Since worms can be found by the hundreds or even thousands on one individual crab, their presence can contribute to brood loss in this economically important species. A three-year sampling program in Oregon’s Coos Bay Estuary is being conducted to estimate the level of infestation of crabs there. Crabs are trapped throughout the year using crab pots in different locations around the bay, checked for worms, measured, sexed, and released. The data suggest that crabs in the lower estuary are more likely to carry worms and are more heavily infected. In addition, laboratory experiments have shown that both juvenile and larval worms are sensitive to the lower salinity conditions that they might experience in the upper estuary. These data suggest that the lower-salinity waters of the estuary may be creating a spaciotemporal refuge for crab hosts from their nemertean egg predators.