Blue-spotted Salamander, Ambystoma laterale, Photographed in Clare County, Michigan
Unisexual Hybrid Salamander, Ambystoma sp., Photographed in Oakland County, Michigan
Unisexual hybrids can be diploid, triploid, or even tetraploid. These animals share the genotypes of the Blue-Spotted, Jefferson's, Smallmouth, and occasionally Eastern Tiger Salamander. These unisexually female salamanders migrate to breeding pools with other salamanders on warm, rainy spring nights where they utilize sperm from males of other Ambystoma species to fertilize their eggs. The sperm of the males stimulates unreduced eggs to develop, resulting in clones of the female, this is a process known as kleptogenesis. It is also possible for the genome to be replaced or for the number of chromosomes in the offspring to be increased. The genetics of these salamanders is still undergoing study by many researchers.