Invasions of ecosystems by exotic species have been the focus of a growing body of research in applied biology and ecology, but relatively little attention has been paid to their economic consequences. Even where economic estimates have been made these often make ad hoc assumptions about the biological relationships of interest and lack grounding in economic theory. This paper develops an integ...

The quantitative importance of ctenophores, medusae, salps and other gelatinous organisms in pelagic ecosystems has been recognized widely for over two decades (Alldredge, 1984; Longhurst, 1985). The potential for gelatinous zooplankton to affect food web structure is illustrated dramatically in the Black Sea where a ctenophore, Mnemiopsis leidyi Agassiz, 1865, was introduced from North America...

Gelatinous zooplankton play an important role in marine food webs both as major consumers of metazooplankton and as prey of apex predators (e.g., tuna, sunfish, sea turtles). However, little is known about the effects of crude oil spills on these important components of planktonic communities. We determined the effects of Louisiana light sweet crude oil exposure on survival and bioaccumulation ...

The lobate ctenophore Mnemiopsis leidyi occurs throughout Narragansett Bay, Rhode Island, during warm summer months but is often undetectable in the central portion of the bay during winter months. During 2 yr of weekly sampling, we found that M. leidyi populations in a shallow embayment, Greenwich Cove, either overwintered or were only briefly absent during winter. The Greenwich Cove populatio...

The TGF-β signaling pathway is a metazoan-specific intercellular signaling pathway known to be important in many developmental and cellular processes in a wide variety of animals. We investigated the complexity and possible functions of this pathway in a member of one of the earliest branching metazoan phyla, the ctenophore Mnemiopsis leidyi. A search of the recently sequenced Mnemiopsis genome...