| Abstrakt: |
Three recent range extensions for the Chesapeake Bay, Virginia, veined rapa whelk (Rapana venosa) population are described. These extensions into Tangier Sound, the mid James River estuary, and to Cape Henry at the Bay mouth extend respectively, the northern, western, and southeastern boundaries of the occupied rapa whelk range in Virginia waters. Salinity and tidal circulation mediate the distribution of adults and larvae of this animal. During dry years (e.g., 2001 and 2002) adult rapa whelks may move up-estuary in western tributaries like the James River, given increased salinity and available habitat and food resources. Declines in salinities (or return to normal salinities) will either kill the rapa whelks in the upriver habitats or force a return to downstream habitats. [ABSTRACT FROM AUTHOR] |
