Accession Number : ADA293200

Title :   Studies of Heat Tolerance of Zebra Mussels: Effects of Temperature Acclimation and Chronic Exposure to Lethal Temperatures.

Descriptive Note : Final rept.

Corporate Author : TEXAS UNIV AT ARLINGTON DEPT OF BIOLOGY

Personal Author(s) : McMahon, Robert F. ; Matthews, Milton A. ; Ussery, Thomas A. ; Chase, R. ; Clarke, Michael

PDF Url : ADA293200

Report Date : FEB 1995

Pagination or Media Count : 33

Abstract : Chronic (i.e., long-term incipient) upper lethal temperatures were determined for zebra mussels (Dreissena polymorpha) acclimated to 5, 10, 15, 20, 25, or 30 degress C for at least 14 days. Subsamples (n=25-33) from each acclimation group were exposed to constant temperatures of 31, 32,33, 34, 35, 36, or 37 degrees C (+ or - 0.1 C). Mussels were brought from acclimation temperature to test temperature by increasing media temperature at a rate of 1 C/10 min. After reaching the test temperature, mortality was determined every 15 min for the first 2 hr, every 30 min for the next 3 to 5 hr, and every hr for the next 17 to 21 hr and every 3 to 4 hr thereafter until all individuals had died. Multiple regression analysis indicated that acclimation temperature, exposure temperature, and mussel shell length (SL) were significantly correlated (P<0.00001) with the natural log of thermal tolerance time. Tolerance time increased with increasing acclimation temperature and decreasing SL and decreased with increased exposure temperature. LT(50) values (i.e., estimated time for 50-percent sample mortality) ranged from 1 hr at 37 degrees C regardless of acclimation temperature to 456 hr in 25 degrees C-acclimated individuals at 31 degree C. (AN)

Descriptors :   *MUSSELS, *HEAT TOLERANCE, MATHEMATICAL MODELS, EXPERIMENTAL DATA, EXPOSURE(GENERAL), HIGH TEMPERATURE, HEAT TREATMENT, ESTIMATES, REGRESSION ANALYSIS, FRESH WATER, LETHALITY, MORTALITY RATE, TOLERANCES(PHYSIOLOGY), FOULING ORGANISMS, ACCLIMATIZATION.

Subject Categories : Biology

Distribution Statement : APPROVED FOR PUBLIC RELEASE