A review of colour phenotypes of the Eastern Red-backed Salamander, <em>Plethodon cinereus</em>, in North America

Abstract

Moore, Jean-David, and Martin ouellet. 2014. A review of colour phenotypes of the Eastern Red-backed Salamander, Plethodon cinereus, in North America. Canadian Field-Naturalist 128(3): 250-259.the Eastern Red-backed Salamander (Plethodon cinereus) is the most abundant salamander species in many forests of northeastern North America. it is well-known for its colour polymorphism, which includes eight colour phenotypes: the red-backed (striped), lead-backed (unstriped) and erythristic morphs, as well as the iridistic, albino, leucistic, amelanistic and melanistic anomalies. Here we review the various colorations of P. cinereus, with the objective of facilitating the identification of these different phenotypes and of generating interest among field herpetologists and scientists reporting on this species. We also list six previously unpublished occurrences of colour variants in this species (1 case of erythrism, 3 of iridism, 1 of leucism, and 1 of partial leucism). to our knowledge, these cases include the first documented occurrence of iridism in the red-backed morph of P. cinereus, and the first two mentions of this colour anomaly in the lead-backed morph from Canada. showed that they are of the same species (Highton 1959). Both morphs can be found across the species range, throughout southeastern Canada and the eastern united States (Petranka 1998), but in very different proportions (Moore and ouellet 2014). in some areas, both morphs are abundant, while in others, one or the other is more abundant. Monomorphic red-backed populations are not uncommon, while in other cases, redbacked individuals can be scarce or absent (thurow 1955;Highton 1959;Pfingsten and Walker 1978;Reichenbach 1981;Fisher-Reid et al. 2013). the redbacked morph has been reported in five Canadian provinces and 22 American states (table 2), which represents the distribution range of this species. Kentucky, Minnesota, and tennessee are at the limit of the species' range and the lead-backed morph of P. cinereus has not been reported there. in the last decades, studies have suggested that the lead-backed morph of P. cinereus is more closely associated with warmer climates than the red-backed morph (lotter and Scott 1977;Moreno 1989;Gibbs and Karraker 2006; Anthony et al. 2008). However, it seems that the possible role of climate in the distribution of the lead-backed morph has never been unanimously recognized; some doubts still persist in the scientific community about the validity of using this morph as indicator of climatic changes (Angleberger and Chinnici 1975;Pfingsten and Walker 1978; Petruzzi et al. 2006; Anthony et al. 2008). Based on new discoveries in the northern areas of the species' range and on the largest compilation ever made for this species, Moore and ouellet (2014) demonstrate however that climate and geographic variables do not influence the colour morph proportions in P. cinereus populations. Fitzpatrick et al. (2009) mentioned that the most reasonable hypothesis to explain the existence of visual polymorphism across a geogr...

Silver-white Variants of the Eastern Red-backed Salamander, <i>Plethodon cinereus</i>, from Eastern Canada

“…In these occurrences, the dorsal stripes vary from gray to silver-white or white. Silver-white variants are thus characterized by the absence of visible xanthophores on the mid-dorsal stripe, compared with other variations of P. cinereus, which usually involve yellow and/or red pigment cells (Moore and Ouellet 2014). This phenotype of P. cinereus should be distinguished from the cream-backed variant (Figure 4 in Moore and Ouellet 2014) and similar colour combinations ("creamy-white stripe" in Reed 1955).…”

“…This salamander's striking colour polymorphism has long attracted the attention of herpetologists and naturalists. Eight colour phenotypes are known and have been recently reviewed (Moore et al 2012;Moore and Ouellet 2014). The red-backed (striped) and lead-backed (unstriped) morphs occur in most populations of P. cinereus, but in very different proportions (Moore and Ouellet 2015).…”

“…The red-backed (striped) and lead-backed (unstriped) morphs occur in most populations of P. cinereus, but in very different proportions (Moore and Ouellet 2015). The erythristic morph is also sporadically observed, but the iridistic, albino, leucistic, amelanistic, and melanistic anomalies are much rarer (Moore and Ouellet 2014).…”

“…Mid-dorsal stripe colours other than redorange, such as shades of brown, gray, pink, white, and yellow, have also been reported (Bishop 1941;Test and Bingham 1948;Schueler 1975;Moore and Ouellet 2014). Surprisingly, little photographic evidence of these colour variations exists in the published literature.…”

Potential change in the distribution of an abundant and wide-ranging forest salamander in a context of climate change

“…Most of its present distribution range (Moore and Ouellet 2015) is encompassed in a large territory that, until recently on a geological timescale, was glaciated and uninhabitable. Although some recent studies have discussed the possible effect of climate on the distribution of the color phenotypes (Gibbs and Karraker 2006, Moore and Ouellet 2015, Cosentino et al 2017) of this polymorphic species Ouellet 2014, Ouellet andMoore 2016), little is known about its climatic niche. Previously, we assembled a large dataset for this species (236,109 observations in 1148 localities and dating from 1880 to 2013) to test color morphs in P. cinereus populations as an indicator of climate change (Moore and Ouellet 2015).…”