Hybrid enrichment identified a single, low-frequency myotoxin SNP across the range of C. adamanteus. We sequenced myotoxin exons 2 and 3 for 140 individuals; each point represents an individual. One-hundred and thirty-one samples possessed mean coverage for both exons; no sequence was obtained for either exon for nine individuals, indicating the locus was absent from the genome (gray points). For the 131 samples with sufficient coverage, we found no sequence variation in exon 3 and only a single nonsynonymous SNP in exon 2, which was present in only four individuals. We plotted the frequency of each allele, the reference allele and the alternative, nonsynonymous variant identified in exon 2, for each individual; pie charts indicate the percentage of duplicates with a particular allele within each individual.