Tolerance of the Nematode Caenorhabditis elegans to pH,Salinity, and Hardness in Aquatic Media |
| |
Authors: | N Khanna C P Cressman III C P Tatara P L Williams |
| |
Institution: | (1) Environmental Health Science Program, College of Agricultural and Environmental Sciences, University of Georgia, Athens, Georgia 30602-2102, USA , US;(2) Institute of Ecology, University of Georgia, Athens, Georgia 30602-2102, USA , US |
| |
Abstract: | The toxicity of many chemicals depends on the physical
conditions of the test environment, and any change or adjustment made to the
tests can alter the results. Therefore it is important to establish the
sensitivity of the test organism over a range of test conditions to determine
when it is necessary to make adjustment and to what extent. In this study, we
established the tolerance range of the nematode Caenorhabditis
elegans for pH, salinity and hardness using 24- (without food source) and
96-h (with food source) aquatic toxicity tests. The tests were performed in
two media: K-medium and moderately hard reconstituted water (MHRW). C.
elegans has high tolerance under these test conditions. In K-medium worms
survived a pH range of 3.1 to 11.9 for 24 h and 3.2 to 11.8 for 96 h without
significant (p > 0.05) lethality. In MHRW the pH range was 3.4 to 11.9 for
24 h and 3.4 to 11.7 for 96 h. Salinity tolerance tests were approximated
with NaCl and KCl individually. Up to 15.46 g/L NaCl and 11.51 g/L KCl were
tolerated by C. elegans in K-medium without significant lethality (p
> 0.05). In MHRW higher salt concentrations were tolerated; about
20.5 g/L NaCl and 18.85 g/L KCl did not show any adverse effect compared to
control. Hardness tolerance was tested by adding NaHCO3. The
nematode could tolerate 0.236 to 0.246 g/L of NaHCO3. The high
tolerance of C. elegans to these test conditions (pH, salinity, and
hardness) allows more versatility than other organisms commonly used in
aquatic toxicity tests. It also allows the monitoring of effluents and
receiving waters from freshwater or estuarine sources without dilution or
adjustment.
Received: 14 February 1996/Revised: 20 June 1996 |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|