The Thick Water Diet

From September, 1994 (update #22)

FRIDAY HARBOR, Wash. - Biologists generally observe that "cold-blooded" invertebrates, such as zebra mussels, feed more slowly at low temperatures. They usually attribute this to the fact that physiological processes slow down at lower temperatures. But slower feeding by planktonic invertebrate larvae at low temperatures may result from changes in water viscosity rather than temperature, according to a July 1 report in "Science" by University of Washington zoologist Robert Podolsky. Podolsky observed that feeding by sand dollar larvae, which are slightly larger than zebra mussel veligers, declined just as much due to changes in water viscosity at low temperatures as to physiological effects of low temperature. Simply stated: It's hard to strain food out of water when it's thick as molasses. "The biological effects of viscosity may prove to be especially important in freshwater systems," Podolsky said.

ID: 199409-5.

The Zebra Mussel Update was a 4- to 8-page quarterly national newsletter published by the University of Wisconsin Sea Grant Institute from May 1990 through May 1997. The ZMU documented the spread of the zebra mussel -- an exotic nuisance mussel -- through North America's freshwater environments, especially the Great Lakes, and on efforts to control it.