1. POPULATION STRUCTURE OF THE SPOTTED SALAMANDER (Ambystoma Maculatum)
IN NORTH CAROLINIAN PONDS
Halley Watson, Cindy Vigueira, and Charles Smith
High Point University
I. Background
ABSTRACT
Vernal pools are unique habitats that promote growth, gene flow and
variation among demes. In addition to more-developed ponds and
lakes, these pools serve as breeding grounds for many amphibians,
including the spotted salamander (Ambystoma maculatum), which is
found in sub-aquatic habitats throughout most of the Eastern United
States. Recently, isolation of these habitats has become a concern
and issues in regards to genetic diversity and population structure of
the spotted salamander could give insight to the long-term health of
these populations. We have compared the genomic similarity of A.
maculatum embryos from different aquatic locations in the Uwharrie
National Forest through the comparison of microsatellite markers and
Nested PCR. The findings of this study will lead to promoting better
conservation methods for this species and a better understanding of
the population biology and habitat fragmentation as a whole.
Figure 5. Google Earth image of
the sample sites and their
distances in respect to one
another. Ponds north to south,
respectively, are Robbins Branch
Trail Pond, Badland Upland
Depression Pond, and Gate Pond.
Figure 2. The
geographic
distribution of the
spotted salamander
in the United States
and Canada.
Figure 3. Two of the three vernal pools that salamander embryos were
collected from in the Uwharrie National Forest.
II. Methods
III. Results
Figure 4. Uwharrie
National forest is found
in central North
Carolina.
Figure 1. Ambystoma maculatum have a complex life cycle that can be
broken up into three stages (pictured above). The embryonic and juvenile
stages spend their life in the water while adults are mainly terrestrial.
Individuals migrate locally every year up to 250 meters to their native pond
which can be broken up by fragmentation. Fragmentation not only threatens
deme isolation but may lead to a loss of genetic diversity as a whole.
Figure 7. Nested PCR mechanismFigure 6. Microsatellite PCR mechanism
Figure 11. Sequence alignment of FAT_4. Characters in color symbolize
nucleotide diversity among individuals.
~14 miles
~0.5 miles
Figure 8. Markers that were sent for sequencing
Figure 9. (left) Successful
amplification of DNA samples
with Ama5-1 microsatellite
primer.
Figure 10. (right) Successful
PCR amplification with nested
KIAA_20 primer set.
CONCLUSIONS
Based on the data we have collected so far, it is evident that there is
genetic variance in individuals from the ponds sampled. Future
directions include running the rest of the primer sequences through
population genetics software, and eventually comparing our results
from Ambystoma maculatum to similar species found in North
Carolina. We eventually hope to use the data collected from these
studies to determine the effects of habitat fragmentation and to
decide whether conservation efforts will one day be necessary for
salamander species in North Carolina.
Figure 12. Comparison of FAT_4
nucleotide diversity among egg
masses. Variation in bar heights
indicates among sibling diversity
within egg masses.
Figure 13. Comparison of genetic
diversity among three sample ponds.
The Badland Upland Depression
pond shows the greatest diversity at
FAT_4.
Figure 14. Comparison of genetic
divergence between ponds. FAT_4
divergence is highest between
Badland Upland Depression pond
and the other two ponds.
