Ambystoma jeffersonianum

Taxonomic recognition of asexual forms that combine genomes of this species, A. laterale, A. texanum, and A. tigrinum raises complex issues. These include discordance between cytoplasmic and nuclear genes, reticulate evolution, and genome-swapping (Bogart 2003). Bi and Bogart (2010) confirm an ancient origin for the mitochondrial genome shared by asexual forms of this complex. Dubois and Rafaëlli (2012) resurrected the name platineum for the asexual forms (Crother 2017).

To accommodate the genetic variation in these salamanders (and the often uncertain genetic composition of particular populations), we have established for this database the following elements: (1) Ambystoma jeffersonianum (Jefferson Salamander), used for pure populations only; (2) Ambystoma laterale (Blue-spotted salamander), used for pure populations only; (3) Ambystoma hybrid pop. 1 (jeffersonianum x laterale; jeffersonianum genome dominates), used for hybrid populations dominated by the jeffersonianum genome (e.g., populations that include mainly LJJ individuals); this element includes "Ambystoma platineum"; (4) Ambystoma hybrid pop. 2 (jeffersonianum x laterale; laterale genome dominates), used for hybrid populations dominated by the laterale genome (e.g., populations that include mainly LLJ individuals); this element includes "Ambystoma tremblayi"; (5) Ambystoma pop. 3 (jeffersonianum/laterale complex - uncertain composition), used for populations for which chromosomal representation is unknown. If needed we could establish additional elements for hybrid populations that involve A. laterale, A. texanum, and/or A. tigrinum.

Also see Kraus (1985), Bogart and Licht (1987), Bogart et al. (1987), Kraus et al. (1991), Lowcock et al. (1991), and Bogart and Klemens (1997) for information on the involvement of A. jeffersonianum in hybridization with A. texanum, A. tigrinum, and/or A. laterale. See Lowcock et al. (1987) and Bogart and Klemens (1997) for discussions of nomenclatural treatment of hybrid populations.

See Kraus (1988), Shaffer et al. (1991), and Jones et al. (1993) for phylogenetic analyses of North American Ambystoma.

This species is widespread in eastern North America. It is threatened by habitat loss, especially uplands surrounding breeding wetlands. The current population trend is unknown, but the species has reportedly declined compared to historical levels.

This species is found in North America in the eastern United States and adjacent Ontario, Canada (Conant and Collins 1991, Petranka 1998, COSEWIC 2010). The range extends from western Illinois and western Kentucky northeastward to southern New York and Ontario (Conant and Collins 1991, Petranka 1998, COSEWIC 2010). Pure diploid populations have been confirmed throughout Pennsylvania and in southern New York (Bogart and Klemens 2008), east-central Illinois (Phillips et al. 1999), and Ontario (COSEWIC 2010). Using select Global Biodiversity Information Facility (GBIF) (2025) records from within the accepted diploid range, range extent is estimated to be approximately 675,000 km² (RARECAT 2024).

No pure diploid A. jeffersonianum populations were found northeast of New York in Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, or Vermont (Bogart and Klemens 2008).

There are many occurrences throughout the range, although determining which populations are pure diploids is challenging (Petranka 1998, Phillips et al. 1999, Bogart and Klemens 2008, COSEWIC 2010).

Vulnerable to detrimental alteration of vernal pool breeding sites, especially as a result of residential development (COSEWIC 2010). Threats to local populations likely include intensive timber harvesting practices that reduce canopy closure, understory vegetation, uncompacted forest litter, or coarse woody debris (moderately to well-decayed) in areas surrounding breeding sites (deMaynadier and Hunter 1999). Some local populations incur heavy road mortality during migrations to and from breeding sites (Klemens 1993, COSEWIC 2010).