Genetic Diversity of the Eastern Massasauga (Sistrurus catenatus) in Berrien and Van Buren Counties, Southwest Michigan
Department of Biology
Berrien Springs, MI USA
The Eastern Massasauga rattlesnake (Sistrurus catenatus; EMR) is a small robust pitviper currently found in nine states and the province of Ontario, Canada. EMR wetland habitats have experienced significant destruction and fragmentation by humans and as a result the current distribution of the EMR is a fraction of its historic distribution. For this reason, the EMR has been federally listed as threatened. A recent analysis of the mitochondrial NADH dehydrogenase (ND2) gene from 179 individuals from 34 unique locations throughout the EMR range found 18 unique haplotypes that cluster into three groups that corresponded to the following geographic regions: western cluster in Iowa, Wisconsin and Illinois; central cluster in Indiana, southern and central Michigan, and Ohio; and eastern cluster in Pennsylvania, New York, Ontario and northern Michigan. The exact boundary between the western and eastern clusters is not known due to the lack of samples from Berrien and Van Buren Counties in southwest Michigan and counties in northwest Indiana. The objective of our study was to determine the genetic diversity of EMRs in Berrien & Van Buren County, Michigan to add clarity to the boundary between the western and central clusters. A total of 11 EMRs were captured from three locations during three field seasons (2015-2017). Blood samples were collected from the caudal vein and DNA was extracted. The mitochondrial ND2 gene was amplified by polymerase chain reaction (PCR) and sequenced using the Sanger dideoxy method. Results, although based on few samples, indicate that all three EMR haplotype clusters are represented within Berrien and Van Buren Counties, including a new undescribed transitional haplotype between the eastern and western clusters.