38 
Charles R. Blem and Leann B. Blem 
Pough (1976) and Pough and Wilson (1977) found that New York 
populations of the spotted salamander suffered high mortality of larvae 
at a pH lower than 6.0, and the species has declined or disappeared 
from parts of the northeastern United States. However, Cook (1983), 
working with spotted salamanders at sites within the Connecticut Valley 
of Massachusetts, found that the percent of mortality of embryos /larvae 
was small (i.e., usually less than 20%) in ponds of pH 4.2 to 6.0. He 
concluded that survival of embryos /larvae in some populations of the 
spotted salamander indicated embryonic acid tolerance, an idea echoed 
by others (see Pierce 1985). The present study examines a similar 
apparent tolerance of acidity in coastal plain and piedmont populations 
of the spotted salamander in Virginia. 
MATERIALS AND METHODS 
Studies were conducted in the spring (February - April) of 1983 
through 1986. Initially we surveyed temporary ponds in six counties 
(Charles City, Chesterfield, Goochland, Hanover, Henrico, and 
Powhatan) of the coastal plain and piedmont of east-central Virginia. 
We specifically looked for egg masses, larvae, and spermatophores in all 
168 temporary ponds we encountered. 
In 64 of the ponds, we measured pH by means of an electronic, 
portable meter (Digital Mini-pH meter) and confirmed these 
determinations with two laboratory meters (Corning and Orion), Merck 
colorpHast pH paper, or both. The pH of the remaining 104 ponds was 
not measured, in the interest of time, because the ponds were near 
others whose pH was known, or for both reasons. Although the point is 
seldom mentioned in the literature, pH is difficult to measure in low 
conductivity waters such as those encountered in temporary ponds. We 
therefore were careful to duplicate most determinations with at least 
two different meters, or with a meter and pH paper. Different techniques 
never produced pH’s that differed by more than 0.2; duplicate 
measurements were averaged in those instances where two methods 
were used. Additionally, we confirmed most determinations by adding 
small amounts of KC1 to aliquots of the solution to be tested before 
using a pH meter. This increases the conductivity of the solution and 
increases the accuracy and speed of measuring pH (F. Hawkridge, pers. 
comm.). 
Tests of pH-related mortality were performed on A. maculatum egg 
masses that were removed from a temporary pond in Chesterfield 
County, Virginia. This site is within the coastal plain and is acidic 
(mean pH = 4.35 ± 0.30; calculated from 22 determinations made on 
different days over a span of 4 years). One-liter aquaria filled with water 
from the temporary pond were used for all tolerance tests as well as 
